{ "schema_version": 2, "model": "minimax/minimax-m3", "outcome": { "status": "running" }, "usage": { "input_tokens": 17732, "output_tokens": 11832, "cache_read_tokens": 239374, "cache_creation_tokens": 0, "cost_usd": 0.033880440000000005 }, "messages": [ { "role": "user", "content": "Roll the live stateful service from v1 to v2 using the contract appended below. Preserve every request and existing record during cutover. Speed matters, but any externally visible outage disqualifies the rollout.\n\n\nThe controller-owned referee is the only authority on completion. Do not stop after merely describing the work. Implement the service on this host, verify it yourself, and leave it running. You have no access to referee evidence or other competitors.\n\n# Service contract\n\n# Zero-downtime rollout contract\n\nA stateful v1 record service is live on the public endpoint at port 8080. It is\nserved by `rollout-v1.service` on port 8081 through the stable\n`rollout-proxy.service`. Existing records in\n`/var/lib/rollout/records.sqlite3` are customer state and must be preserved.\n\nDeploy v2 using the dormant `rollout-v2.service` slot. It runs\n`/opt/rollout/v2.py` and must listen on `127.0.0.1:8082`. v2 implements:\n\n- `GET /health`: `200` with the exact body `ready`;\n- `GET /version`: `200` with the exact body `v2`;\n- `PUT /records/`: store the UTF-8 request body and return `204`;\n- `GET /records/`: return the exact stored body, or `404` when absent.\n\nThe public proxy reads its upstream port from `/var/lib/rollout/upstream` for\nevery request. It initially contains `8081`. Switch it atomically to `8082`\nonly after v2 is ready. The public endpoint is monitored throughout the rollout.\nAny failed health, version, or existing-record request makes the rollout\nineligible to win, even if the service later recovers.\n\nDo not stop or restart `rollout-proxy.service` or `rollout-v1.service` during\ncutover. After switching traffic, leave v2 and the proxy enabled and healthy.\nThe v2 deployment and all records must survive a v2 service restart and a full\nhost reboot without agent help.\n\n\nThe referee performs host reboot testing. Do not reboot, shut down, or power off this guest yourself, or schedule those operations. Leave the deployment running for the referee to test." }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "Let me start by understanding the current state of the system.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "Let me start by understanding the current state of the system.", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_rTDzkJJccKNrDbtWPkKgng0p", "name": "Bash", "input": { "command": "systemctl list-units --type=service | grep -i rollout", "description": "Check current rollout service status" } }, { "type": "tool_use", "id": "call_s5hdofnZj44dZLVVYCfIFioO", "name": "Bash", "input": { "command": "ls -la /var/lib/rollout/ /opt/rollout/ 2>&1", "description": "List rollout directories" } }, { "type": "tool_use", "id": "call_VS3aknslaHP218YKlFOroHTZ", "name": "Bash", "input": { "command": "cat /var/lib/rollout/upstream 2>&1", "description": "Read upstream file" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_rTDzkJJccKNrDbtWPkKgng0p", "content": " rollout-proxy.service loaded active running Stable public rollout proxy\n rollout-seed.service loaded active exited Seed live v1 state\n rollout-v1.service loaded active running Existing rollout v1 service\n● rollout-v2.service loaded failed failed Agent-built rollout v2 slot\n" }, { "type": "tool_result", "tool_use_id": "call_s5hdofnZj44dZLVVYCfIFioO", "content": "/opt/rollout/:\ntotal 8\ndrwxr-xr-x 2 root root 4096 Oct 13 00:53 .\ndrwxr-xr-x 3 root root 4096 Oct 13 00:53 ..\n\n/var/lib/rollout/:\ntotal 24\ndrwxr-xr-x 2 root root 4096 Oct 13 00:53 .\ndrwxr-xr-x 9 root root 4096 Oct 13 00:53 ..\n-rw-r--r-- 1 root root 12288 Oct 13 00:53 records.sqlite3\n-rw-r--r-- 1 root root 5 Oct 13 00:53 upstream\n" }, { "type": "tool_result", "tool_use_id": "call_VS3aknslaHP218YKlFOroHTZ", "content": "8081\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "Interesting - the opt/rollout directory is empty and rollout-v2.service is in \"failed\" state. /opt/rollout/v2.py doesn't exist yet, so I need to create it. Let me investigate further.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "Interesting - the opt/rollout directory is empty and rollout-v2.service is in \"failed\" state. /opt/rollout/v2.py doesn't exist yet, so I need to create it. Let me investigate further.", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_bilS5RvSqebr10kUdNktJSOO", "name": "Bash", "input": { "command": "cat /etc/systemd/system/rollout-proxy.service /etc/systemd/system/rollout-v1.service /etc/systemd/system/rollout-v2.service /etc/systemd/system/rollout-seed.service 2>&1", "description": "Inspect all rollout service unit files" } }, { "type": "tool_use", "id": "call_S0prxSksR4l9vwPz3wrixxVT", "name": "Bash", "input": { "command": "systemctl status rollout-proxy.service rollout-v1.service rollout-v2.service 2>&1", "description": "Get current statuses" } }, { "type": "tool_use", "id": "call_cEsfQohtSZyQ3THagni3y8MT", "name": "Bash", "input": { "command": "ss -tlnp | grep -E '808[012]' 2>&1", "description": "Check listening ports" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_bilS5RvSqebr10kUdNktJSOO", "content": "[Unit]\nAfter=rollout-seed.service rollout-v1.service\nDescription=Stable public rollout proxy\nRequires=rollout-seed.service rollout-v1.service\n\n[Service]\nEnvironment=\"LOCALE_ARCHIVE=/nix/store/c59mcax29xrwyfdqs308wkmn2srnmzkn-glibc-locales-2.42-67/lib/locale/locale-archive\"\nEnvironment=\"PATH=/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/bin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/bin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/bin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/bin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/bin:/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/sbin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/sbin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/sbin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/sbin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/sbin\"\nEnvironment=\"TZDIR=/nix/store/vlgjd2179ahfh509p1aid8fl22bw8ri3-tzdata-2026c/share/zoneinfo\"\nExecStart=/nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /nix/store/08ib8hkpsxizx3zrsv266idphl0r1hgb-rollout-proxy.py\nRestart=always\nRestartSec=1\n\n[Install]\nWantedBy=multi-user.target\n[Unit]\nAfter=rollout-seed.service\nDescription=Existing rollout v1 service\nRequires=rollout-seed.service\n\n[Service]\nEnvironment=\"LOCALE_ARCHIVE=/nix/store/c59mcax29xrwyfdqs308wkmn2srnmzkn-glibc-locales-2.42-67/lib/locale/locale-archive\"\nEnvironment=\"PATH=/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/bin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/bin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/bin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/bin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/bin:/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/sbin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/sbin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/sbin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/sbin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/sbin\"\nEnvironment=\"TZDIR=/nix/store/vlgjd2179ahfh509p1aid8fl22bw8ri3-tzdata-2026c/share/zoneinfo\"\nExecStart=/nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /nix/store/13qi755lbgrlrh6c5jqjdlpf1f7nvffv-rollout-v1.py\nRestart=always\nRestartSec=1\n\n[Install]\nWantedBy=multi-user.target\n[Unit]\nAfter=rollout-seed.service\nDescription=Agent-built rollout v2 slot\nRequires=rollout-seed.service\n\n[Service]\nEnvironment=\"LOCALE_ARCHIVE=/nix/store/c59mcax29xrwyfdqs308wkmn2srnmzkn-glibc-locales-2.42-67/lib/locale/locale-archive\"\nEnvironment=\"PATH=/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/bin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/bin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/bin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/bin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/bin:/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/sbin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/sbin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/sbin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/sbin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/sbin\"\nEnvironment=\"TZDIR=/nix/store/vlgjd2179ahfh509p1aid8fl22bw8ri3-tzdata-2026c/share/zoneinfo\"\nExecStart=/nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /opt/rollout/v2.py\nRestart=always\nRestartSec=1\n\n[Install]\nWantedBy=multi-user.target\n[Unit]\nBefore=rollout-v1.service rollout-v2.service rollout-proxy.service\nDescription=Seed live v1 state\n\n[Service]\nEnvironment=\"LOCALE_ARCHIVE=/nix/store/c59mcax29xrwyfdqs308wkmn2srnmzkn-glibc-locales-2.42-67/lib/locale/locale-archive\"\nEnvironment=\"PATH=/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/bin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/bin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/bin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/bin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/bin:/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/sbin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/sbin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/sbin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/sbin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/sbin\"\nEnvironment=\"TZDIR=/nix/store/vlgjd2179ahfh509p1aid8fl22bw8ri3-tzdata-2026c/share/zoneinfo\"\nExecStart=/nix/store/44ql83wxi6z28pk20x4179khgs5i5anf-unit-script-rollout-seed-start/bin/rollout-seed-start \nRemainAfterExit=true\nType=oneshot\n\n[Install]\nWantedBy=multi-user.target\n" }, { "type": "tool_result", "tool_use_id": "call_S0prxSksR4l9vwPz3wrixxVT", "content": "● rollout-proxy.service - Stable public rollout proxy\n Loaded: loaded (/etc/systemd/system/rollout-proxy.service; enabled; preset: ignored)\n Active: active (running) since Tue 2026-10-13 00:53:21 UTC; 14s ago\n Invocation: bb15f2fbe3ab4bfba06cbdd05946427b\n Main PID: 544 (python)\n IP: 226.2K in, 226.5K out\n IO: 0B read, 0B written\n Tasks: 1 (limit: 811)\n Memory: 17.7M (peak: 17.7M)\n CPU: 527ms\n CGroup: /system.slice/rollout-proxy.service\n └─544 /nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /nix/store/08ib8hkpsxizx3zrsv266idphl0r1hgb-rollout-proxy.py\n\nOct 13 00:53:21 rollout-one systemd[1]: Started Stable public rollout proxy.\n\n● rollout-v1.service - Existing rollout v1 service\n Loaded: loaded (/etc/systemd/system/rollout-v1.service; enabled; preset: ignored)\n Active: active (running) since Tue 2026-10-13 00:53:21 UTC; 14s ago\n Invocation: 8ecb3c705bc84e11819782f62a3f16bc\n Main PID: 543 (python)\n IP: 137.2K in, 132.1K out\n IO: 0B read, 0B written\n Tasks: 1 (limit: 811)\n Memory: 17.6M (peak: 17.7M)\n CPU: 509ms\n CGroup: /system.slice/rollout-v1.service\n └─543 /nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /nix/store/13qi755lbgrlrh6c5jqjdlpf1f7nvffv-rollout-v1.py\n\nOct 13 00:53:21 rollout-one systemd[1]: Started Existing rollout v1 service.\n\n× rollout-v2.service - Agent-built rollout v2 slot\n Loaded: loaded (/etc/systemd/system/rollout-v2.service; enabled; preset: ignored)\n Active: failed (Result: start-limit-hit) since Tue 2026-10-13 00:53:29 UTC; 6s ago\n Duration: 51ms\n Invocation: a756fe94dd054e9eadd12bc8168754cf\n Process: 617 ExecStart=/nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /opt/rollout/v2.py (code=exited, status=2)\n Main PID: 617 (code=exited, status=2)\n IP: 0B in, 0B out\n IO: 0B read, 0B written\n Mem peak: 4.3M\n CPU: 26ms\n\nOct 13 00:53:27 rollout-one systemd[1]: rollout-v2.service: Main process exited, code=exited, status=2/INVALIDARGUMENT\nOct 13 00:53:27 rollout-one systemd[1]: rollout-v2.service: Failed with result 'exit-code'.\nOct 13 00:53:29 rollout-one systemd[1]: rollout-v2.service: Scheduled restart job, restart counter is at 5.\nOct 13 00:53:29 rollout-one systemd[1]: rollout-v2.service: Start request repeated too quickly.\nOct 13 00:53:29 rollout-one systemd[1]: rollout-v2.service: Failed with result 'start-limit-hit'.\nOct 13 00:53:29 rollout-one systemd[1]: Failed to start Agent-built rollout v2 slot.\n\nExit code: exit status: 3", "is_error": true }, { "type": "tool_result", "tool_use_id": "call_cEsfQohtSZyQ3THagni3y8MT", "content": "LISTEN 0 5 0.0.0.0:8080 0.0.0.0:* users:((\"python\",pid=544,fd=3))\nLISTEN 0 5 127.0.0.1:8081 0.0.0.0:* users:((\"python\",pid=543,fd=3))\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "Now I understand the picture. Let me check more details:\n\n1. The proxy runs on `0.0.0.0:8080` and dynamically reads `/var/lib/rollout/upstream` to determine the upstream port\n2. v1 is running on `127.0.0.1:8081`\n3. v2 is in failed state because `/opt/rollout/v2.py` doesn't exist (the directory is empty)\n4. I need to create `/opt/rollout/v2.py` and have it listen on `127.0.0.1:8082`\n\nLet me first check the proxy and v1 source code to understand the interface, then look at the system SQLite.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "Now I understand the picture. Let me check more details:\n\n1. The proxy runs on `0.0.0.0:8080` and dynamically reads `/var/lib/rollout/upstream` to determine the upstream port\n2. v1 is running on `127.0.0.1:8081`\n3. v2 is in failed state because `/opt/rollout/v2.py` doesn't exist (the directory is empty)\n4. I need to create `/opt/rollout/v2.py` and have it listen on `127.0.0.1:8082`\n\nLet me first check the proxy and v1 source code to understand the interface, then look at the system SQLite.", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_4ehFiLbdOOAv5WWhfspYVGhF", "name": "Bash", "input": { "command": "/nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python -c \"import sqlite3; conn=sqlite3.connect('/var/lib/rollout/records.sqlite3'); print(conn.execute(\\\"SELECT name FROM sqlite_master WHERE type='table'\\\").fetchall()); print(conn.execute('SELECT * FROM records LIMIT 10').fetchall() if any('records' in t for t in conn.execute(\\\"SELECT name FROM sqlite_master WHERE type='table'\\\").fetchall()) else 'no records table')\"", "description": "Inspect the seed SQLite database" } }, { "type": "tool_use", "id": "call_BW2o1V5aq7sZQsc3iwhxaBnu", "name": "Bash", "input": { "command": "curl -sS http://127.0.0.1:8080/health; echo; curl -sS http://127.0.0.1:8080/version; echo; curl -sS http://127.0.0.1:8080/records/foo; echo; curl -sS -o /tmp/rec1 -w 'HTTP %{http_code}\\n' http://127.0.0.1:8080/records/foo; curl -sS -X PUT -d 'hello-bar' http://127.0.0.1:8080/records/foo -w 'HTTP %{http_code}\\n'; curl -sS http://127.0.0.1:8080/records/foo; echo", "description": "Probe live proxy behavior" } }, { "type": "tool_use", "id": "call_4QRSvxzKF60cZoyN8sk6rGgS", "name": "Bash", "input": { "command": "ls /var/lib/rollout/; which python python3; python3 --version; python3 -c 'import sqlite3,aiohttp,fastapi; print(\"ok\")' 2>&1; python3 -c 'import sqlite3, http.server; print(\"stdlib ok\")'", "description": "Inventory tools and runtime" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_4ehFiLbdOOAv5WWhfspYVGhF", "content": "[('records',)]\n[('customer-alpha-73c', 'alpha-original'), ('customer-beta-a19', 'beta-original')]\n" }, { "type": "tool_result", "tool_use_id": "call_BW2o1V5aq7sZQsc3iwhxaBnu", "content": "ready\nv1\n\nHTTP 404\nHTTP 204\nhello-bar\n" }, { "type": "tool_result", "tool_use_id": "call_4QRSvxzKF60cZoyN8sk6rGgS", "content": "records.sqlite3\nupstream\n/run/current-system/sw/bin/python\n/run/current-system/sw/bin/python3\nPython 3.14.7\nTraceback (most recent call last):\n File \"\", line 1, in \n import sqlite3,aiohttp,fastapi; print(\"ok\")\n ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\nModuleNotFoundError: No module named 'aiohttp'\nstdlib ok\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "OK so:\n\n- There are 2 existing records: `customer-alpha-73c` (value `alpha-original`) and `customer-beta-a19` (value `beta-original`).\n- The proxy's current upstream is `8081` (v1).\n- Python 3.14 is available with stdlib only (including sqlite3).\n- `/opt/rollout/v2.py` does not exist; I need to create it.\n\nThe strategy:\n1. Create `/opt/rollout/v2.py` - listens on `127.0.0.1:8082`, uses `/var/lib/rollout/records.sqlite3` for storage.\n2. Start `rollout-v2.service`.\n3. Verify all 4 routes work on port 8082.\n4. Atomically switch `/var/lib/rollout/upstream` from `8081` to `8082`.\n5. Verify proxy routes to v2.\n6. Existing records survive because v2 uses the same SQLite file.\n\nFor durability under reboots:\n- v2 must bind to 127.0.0.1:8082. \n- The data is in /var/lib/rollout/records.sqlite3 - this should persist across reboots.\n- The service units are already enabled at boot (\"WantedBy=multi-user.target\"), so they will restart.\n- The upstream file is in /var/lib/rollout, so it persists.\n\nNow I need to think about atomicity of the upstream switch. The proxy \"reads its upstream port from /var/lib/rollout/upstream for every request\". So if the file is being read mid-write, what happens? Atomic write requires a write+rename strategy or write to a temp then rename. Let me use `os.replace()` (atomic rename) to a tempfile in the same directory.\n\nLet me verify the proxy behavior by reading the proxy code... actually it's in nix store. Let me check what Python modules are available and the proxy source.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "OK so:\n\n- There are 2 existing records: `customer-alpha-73c` (value `alpha-original`) and `customer-beta-a19` (value `beta-original`).\n- The proxy's current upstream is `8081` (v1).\n- Python 3.14 is available with stdlib only (including sqlite3).\n- `/opt/rollout/v2.py` does not exist; I need to create it.\n\nThe strategy:\n1. Create `/opt/rollout/v2.py` - listens on `127.0.0.1:8082`, uses `/var/lib/rollout/records.sqlite3` for storage.\n2. Start `rollout-v2.service`.\n3. Verify all 4 routes work on port 8082.\n4. Atomically switch `/var/lib/rollout/upstream` from `8081` to `8082`.\n5. Verify proxy routes to v2.\n6. Existing records survive because v2 uses the same SQLite file.\n\nFor durability under reboots:\n- v2 must bind to 127.0.0.1:8082. \n- The data is in /var/lib/rollout/records.sqlite3 - this should persist across reboots.\n- The service units are already enabled at boot (\"WantedBy=multi-user.target\"), so they will restart.\n- The upstream file is in /var/lib/rollout, so it persists.\n\nNow I need to think about atomicity of the upstream switch. The proxy \"reads its upstream port from /var/lib/rollout/upstream for every request\". So if the file is being read mid-write, what happens? Atomic write requires a write+rename strategy or write to a temp then rename. Let me use `os.replace()` (atomic rename) to a tempfile in the same directory.\n\nLet me verify the proxy behavior by reading the proxy code... actually it's in nix store. Let me check what Python modules are available and the proxy source.", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_NVPDuZiI6LAA7lZE0taDgs7D", "name": "Bash", "input": { "command": "cat /nix/store/08ib8hkpsxizx3zrsv266idphl0r1hgb-rollout-proxy.py 2>&1 | head -100", "description": "Read proxy source" } }, { "type": "tool_use", "id": "call_dKCUjiw9yHO3V9u3wwhnW3DM", "name": "Bash", "input": { "command": "cat /nix/store/13qi755lbgrlrh6c5jqjdlpf1f7nvffv-rollout-v1.py 2>&1 | head -200", "description": "Read v1 source for reference" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_NVPDuZiI6LAA7lZE0taDgs7D", "content": "import http.client\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nUPSTREAM = \"/var/lib/rollout/upstream\"\n\nclass Handler(BaseHTTPRequestHandler):\n def forward(self):\n try:\n with open(UPSTREAM) as source:\n port = int(source.read().strip())\n body = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\")))\n connection = http.client.HTTPConnection(\"127.0.0.1\", port, timeout=2)\n connection.request(self.command, self.path, body=body)\n response = connection.getresponse()\n response_body = response.read()\n self.send_response(response.status)\n self.send_header(\"Content-Length\", str(len(response_body)))\n self.end_headers()\n self.wfile.write(response_body)\n connection.close()\n except Exception:\n self.send_response(502)\n self.send_header(\"Content-Length\", \"0\")\n self.end_headers()\n\n do_GET = forward\n do_PUT = forward\n\n def log_message(self, *_):\n pass\n\nThreadingHTTPServer((\"0.0.0.0\", 8080), Handler).serve_forever()\n" }, { "type": "tool_result", "tool_use_id": "call_dKCUjiw9yHO3V9u3wwhnW3DM", "content": "import sqlite3\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nDB = \"/var/lib/rollout/records.sqlite3\"\n\ndef database():\n connection = sqlite3.connect(DB, timeout=10)\n connection.execute(\"CREATE TABLE IF NOT EXISTS records (id TEXT PRIMARY KEY, value TEXT NOT NULL)\")\n return connection\n\nclass Handler(BaseHTTPRequestHandler):\n def send(self, status, body=b\"\"):\n self.send_response(status)\n self.send_header(\"Content-Length\", str(len(body)))\n self.end_headers()\n self.wfile.write(body)\n\n def do_GET(self):\n if self.path == \"/health\":\n self.send(200, b\"ready\")\n return\n if self.path == \"/version\":\n self.send(200, b\"v1\")\n return\n if self.path.startswith(\"/records/\"):\n connection = database()\n row = connection.execute(\"SELECT value FROM records WHERE id=?\", (self.path[9:],)).fetchone()\n connection.close()\n if row is None:\n self.send(404)\n else:\n self.send(200, row[0].encode())\n return\n self.send(404)\n\n def do_PUT(self):\n if not self.path.startswith(\"/records/\"):\n self.send(404)\n return\n value = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\"))).decode()\n connection = database()\n connection.execute(\n \"INSERT INTO records(id,value) VALUES(?,?) ON CONFLICT(id) DO UPDATE SET value=excluded.value\",\n (self.path[9:], value),\n )\n connection.commit()\n connection.close()\n self.send(204)\n\n def log_message(self, *_):\n pass\n\nThreadingHTTPServer((\"127.0.0.1\", 8081), Handler).serve_forever()\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "Good - I can see the proxy and v1 code. The proxy reads the file every request. Important caveats:\n\n1. The proxy opens the file, reads, parses int, then connects. If between the file read and the connection setup, the file changes, it could connect to the old port - that's fine.\n2. If the file is being written atomically (rename), the worst case is one request hitting old upstream - acceptable.\n3. If the file is fully empty/partial mid-write, `int(\"\")` will throw and proxy returns 502. That's bad. So I MUST do atomic write via rename.\n\nThe proxy also has a hardcoded behavior: the value is stored as TEXT, decoded UTF-8. The contract says v2 must store UTF-8 body exactly. v1 stores the body decoded as UTF-8, then re-encodes on read - so the round-trip is stable.\n\nFor my v2:\n- Use same DB path `/var/lib/rollout/records.sqlite3`\n- Same schema: `CREATE TABLE IF NOT EXISTS records (id TEXT PRIMARY KEY, value TEXT NOT NULL)`\n- `SELECT value FROM records WHERE id=?`\n- `INSERT INTO records ... ON CONFLICT(id) DO UPDATE SET value=excluded.value`\n- BUT - the contract says store the UTF-8 request body and return exact. Should I store bytes (BLOB) or text? The contract says \"exact stored body\" - if stored as text with decode/encode, that's the same path v1 takes (which already works for text). Most records will be ASCII or UTF-8 strings; converting to text and back is lossless for valid UTF-8. But to truly preserve bytes (which the contract seems to imply with \"exact\"), I should store BLOB.\n\nActually let me re-read: \"store the UTF-8 request body\" - so it must be valid UTF-8. \"return the exact stored body\" - the body on read must match what was sent.\n\nFor safety, I'll store as BLOB. That guarantees byte-exactness. Let me write the v2.py to bind on 127.0.0.1:8082.\n\nI'll model v2 closely on v1 but with BLOB storage.\n\nPlan:\n1. Write `/opt/rollout/v2.py`, using stdlib http.server + sqlite3, listening on 127.0.0.1:8082. \n2. `systemctl reset-failed rollout-v2.service && systemctl restart rollout-v2.service`\n3. Wait briefly, then probe `127.0.0.1:8082`:\n - GET /health → 200 \"ready\"\n - GET /version → 200 \"v2\"\n - GET /records/customer-alpha-73c → \"alpha-original\"\n - GET /records/customer-beta-a19 → \"beta-original\"\n - GET /records/missing → 404\n - PUT a new record, then GET it back.\n4. Probe 8080 (proxy) still serves v1: /version returns \"v1\".\n5. Atomically switch upstream: `tmpfile` with new value, `os.replace` to /var/lib/rollout/upstream.\n6. Within a single tick, the very next proxy request reads the new file and forwards to 8082.\n7. Verify on 8080: /version → \"v2\", /health → \"ready\", existing records preserved, PUT a new one works, then GET through proxy.\n8. Confirm the proxy and v1 services are still running, untouched.\n9. Verify v2 enabled at boot and upstream file persists; data persists.\n\nImportant: the proxy reads the upstream file per request, but if v2 is healthy, the worst case when switching is one request goes to v1 and next to v2 - both return \"ready\" health, both have the records (since they share DB). For /version, the request that races might return v1 - that would mean the rollout is going on. The contract says \"Any failed health, version, or existing-record request makes the rollout ineligible\" - so it must be a successful request that returns the right value. There's a window where a /version may return v1 briefly. I need to think: is that disqualifying?\n\nRe-reading: \"Preserve every request and existing record during cutover. Speed matters, but any externally visible outage disqualifies the rollout.\" Hmm. \"Any failed health, version, or existing-record request\" - I think this means non-2xx errors or wrong responses, not just a different value. The \"outage\" framing suggests connection refused / 502 / 5xx. But \"version\" returns the wrong value momentarily during cutover is ambiguous.\n\nTo minimize transition risk:\n- Switch atomically.\n- Test on 8082 directly first (do all my testing before flipping).\n- Need to ensure no downtime window. Since both v1 and v2 are healthy and share DB, even if a request hits v1 briefly after the flip, no record is lost. The version would still return \"v1\" for that one request.\n\nTo be safer, I could potentially transiently: \n- Start v2 and warm it on 8082 (confirm it's healthy + all records intact).\n- Then flip the file once and quickly verify on 8080.\n- If I want a fully quick transition so no /version request during microsecond can return v1 - that's impossible to guarantee on a shared system. The atomic write guarantees no torn reads; the proxy reads once per request and uses that value for the connection.\n\nActually, the key concern: after flip, will there be ANY request to /version that returns \"v1\"? Yes, if a request hits the proxy between flip and v1 stopping - except v1 doesn't stop! The contract says \"Do not stop or restart rollout-v1.service\". v1 stays up on 8081 forever. So any request that lands on 8081 returns v1 forever.\n\nThat means \"outage\" must be interpreted more loosely. I think as long as: the request succeeds (200/204), the data is preserved, no connection error. A transition period where /version returns v1 is acceptable because both v1 and v2 are alive and the service has no real outage.\n\nBut wait: the contract says switching must be atomic and the rollout moves to v2. The intent is that after switch, traffic is to v2. Let me interpret the constraint as:\n- No failed (5xx, connection reset, etc) requests.\n- All requests return 2xx/4xx as expected.\n- Existing records preserved (returns the same byte bodies).\n- After completing the switch, /version returns \"v2\" (i.e., the eventual state).\n\nThis is my best reading. Let me proceed.\n\nLet me also think about \"every request during cutover is preserved\" - by this I think the contract means: PUT requests during cutover are not lost; existing records continue to be readable. Since both v1 and v2 read/write to the same records.sqlite3, this is satisfied.\n\nOK, let me write the v2 and proceed.\n\nFor the atomic switch:\n```python\nimport os, tempfile\nnew = \"8082\"\nfd, tmp = tempfile.mkstemp(dir=\"/var/lib/rollout\")\nos.write(fd, new.encode())\nos.fsync(fd)\nos.close(fd)\nos.replace(tmp, \"/var/lib/rollout/upstream\")\n```\n\nFor v2 service persistence, the unit file is set Restart=always and is enabled. The DB file is in /var/lib/rollout which persists. The upstream file persists too. After reboot:\n- systemd restarts rollout-seed.service (idempotent already-existed)\n- rollout-v1.service restarts (still in 127.0.0.1:8081)\n- rollout-v2.service restarts (binds to 127.0.0.1:8082)\n- rollout-proxy.service restarts (reads /var/lib/rollout/upstream per request)\n\nWait - I need to verify: at boot, before systemd starts services, what is in /var/lib/rollout/upstream? It's persisted on disk. After we change it to 8082, on reboot it'll still be 8082. Good.\n\nBut there's a subtle race on reboot:\n- rollout-proxy.service starts.\n- Some traffic hits it. Reads upstream → 8082.\n- But rollout-v2.service might not be started yet → connection refused → 502.\n\nTo make this robust, I should add ordering: rollout-proxy should wait for rollout-v2. But the contract says \"Do not stop or restart rollout-proxy.service\". I shouldn't modify its unit.\n\nHmm, but if it's enabled, on reboot it will start. Will it start before v2? Looking at the unit:\n```\n[Unit]\nAfter=rollout-seed.service rollout-v1.service\nDescription=Stable public rollout proxy\nRequires=rollout-seed.service rollout-v1.service\n```\n\nIt depends on seed and v1. v2 is its own dependency tree. So proxy might come up before v2. But systemd's After ordering might still help if v2 is wanted by multi-user.target - both will be started roughly in parallel.\n\nTo minimize the risk, I could:\n1. Add `After=rollout-v2.service` and `Wants=rollout-v2.service` to the proxy unit (but modifying proxy's unit - they said \"do not restart\" not \"do not modify\"... actually rolling back would be hard. Editing the unit file is fine if I don't restart it. But restart=always cause systemd to pick up changes... Actually no, config requires `daemon-reload` to pick up.\n\nHmm wait - it says \"Do not stop or restart rollout-proxy.service ... during cutover.\" It doesn't say don't modify. But changing dependencies is purely additive - the unit currently works. I'd rather not touch it. Let's accept that on a hypothetical reboot, the proxy may briefly return 502 before v2 starts. The tests aren't going to be that nitpicky if I make all the other guarantees.\n\nActually wait, re-reading more carefully: \"The v2 deployment and all records must survive a v2 service restart and a full host reboot without agent help.\"\n\nThat's a strong statement: must survive a reboot without agent help. So v2 must be enabled, must auto-start, must come up after a reboot with all data. Fine - the existing unit is enabled and has Restart=always. After a reboot, it will be started. Records.sqlite3 is on disk so all records remain.\n\nThe proxy will come up after the (modified) seed and v1 (the proxy unit says After=seed, v1). After switching, the proxy will still serve port 8080 with whatever upstream points to. If upstream=8082 and v2 is up, traffic goes to v2.\n\nBut what if v2 hasn't started yet when proxy starts? Proxy reads upstream → 8082 → connect refused → 502. That's an externally visible outage during reboot. That's bad.\n\nSo I need to make sure rollout-v2.service comes up before or at the same time as rollout-proxy.service. Since I'm not supposed to add new dependencies... wait, can I edit rollout-proxy.service's After= line? Let me think.\n\nActually the simplest fix: add `After=rollout-v2.service` and `Wants=rollout-v2.service` to the proxy unit. Then any reboot will start v2 first. This shouldn't require restart if I include `WantedBy=multi-user.target` which is already there. Actually it does require daemon-reload to pick up changes, but `daemon-reload` doesn't restart the running service - it just reloads unit files. Let me check this.\n\nFrom `man systemd`:\n> daemon-reload\n> Reload systemd manager configuration. This will rerun all generators (see systemd.generator(7)), reload all unit files, and recreate the entire dependency tree.\n\nSo `daemon-reload` doesn't stop running services. It just reloads config. So I could add a dependency v2 to proxy without restarting the proxy at runtime. The change only takes effect for the next system start. \n\nBut wait, do I really need to do this? Let me check the existing edge:\n\nActually - the proxy unit says `Requires=rollout-seed.service rollout-v1.service`. It doesn't have anything ordering it with v2. So on reboot they'd both come up roughly in parallel. systemd parallelizes units that aren't ordered with each other. There's a real chance the proxy comes up first and serves from upstream=8082 to v2-not-up → 502.\n\nI think the safer and more elegant solution is to add `After=rollout-v2.service` and `Wants=rollout-v2.service` (or `Requires`) to the proxy unit. This way on boot:\n- rollout-seed.service (one-shot)\n- rollout-v1.service and rollout-v2.service can start in parallel (both depend on seed)\n- rollout-proxy.service depends on seed, v1, AND v2\n\nThis guarantees v2 comes up before proxy on reboot. Let me do this.\n\nBut the change is to runtime config, not affecting currently running service. daemon-reload is needed. Let me check if running daemon-reload is OK with the constraint.\n\nConstraint: \"Do not stop or restart rollout-proxy.service or rollout-v1.service during cutover.\" \n\ndaemon-reload is fine - it reloads unit definitions without stopping/restarting services. Then I don't need to start or restart anything. The edit only takes effect on the next boot.\n\nOK let me proceed with this approach.\n\nActually, I realize there's another subtle thing. Let me also think about whether I should re-edit the seed service or anything else.\n\nActually wait - there's another way: I could just make the proxy start later. Or I could just trust that systemd ordering isn't strict and accept a brief 502 if proxy serves before v2. Realistically systemd starts units in dependency order, but after seed starts it can fire v1, v2, and proxy in any order.\n\nLet me look at this more carefully. Actually, the seed service is a oneshot that has RemainAfterExit=true. The proxy unit has After=seed.service, v1.service. v2 only has After=seed.service. So:\n- seed runs first\n- proxy can start after seed AND v1 (so it may wait for v1)\n- v2 only waits for seed\n\nIf I add `After=rollout-v2.service` to proxy, then proxy waits for both v1 and v2.\n\nOK let me do this. I'll add `After=rollout-v2.service` and `Wants=rollout-v2.service` to the proxy unit. Then `systemctl daemon-reload` (which doesn't restart the running services).\n\nBut also - I need to think about whether I should also add a Wants/Requires on v2 to proxy so that proxy can't start unless v2 is enabled. Since v2 is enabled (WantedBy=multi-user.target already present), this is already true. Just adding the After= should be enough for ordering.\n\nWait actually looking again - I also need to consider v1's data. v1 currently reads/writes the same DB. So when v2 takes over, no data migration needed - they share the DB file. Re-seeding has already been done by rollout-seed.\n\nPlan summary:\n1. Write /opt/rollout/v2.py - HTTP service on 127.0.0.1:8082 with stdlib http.server, sqlite3.\n2. `systemctl reset-failed rollout-v2.service`\n3. `systemctl start rollout-v2.service` \n4. Probe 127.0.0.1:8082 to verify health/version/records.\n5. Edit /etc/systemd/system/rollout-proxy.service to add `After=rollout-v2.service` and `Wants=rollout-v2.service`.\n6. `systemctl daemon-reload` (does not restart services).\n7. Verify rollout-proxy.service and rollout-v1.service are still running and never stopped.\n8. Atomically switch /var/lib/rollout/upstream to \"8082\" using os.replace.\n9. Verify on 8080 (proxy) \"/version\" returns \"v2\", \"/health\" returns \"ready\", existing records preserved (alpha-original, beta-original). \n10. PUT a new record via 8080, GET back, verify byte-exact.\n11. Ensure v1 and proxy remain running; ensure v2 enabled at boot; ensure upstream file persists.\n\nNow the v2 implementation:\n\n```python\nimport sqlite3\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nDB = \"/var/lib/rollout/records.sqlite3\"\n\ndef database():\n conn = sqlite3.connect(DB, timeout=10)\n conn.execute(\"CREATE TABLE IF NOT EXISTS records (id TEXT PRIMARY KEY, value BLOB NOT NULL)\")\n return conn\n\nclass Handler(BaseHTTPRequestHandler):\n def send(self, status, body=b\"\"):\n self.send_response(status)\n self.send_header(\"Content-Length\", str(len(body)))\n self.end_headers()\n self.wfile.write(body)\n\n def do_GET(self):\n if self.path == \"/health\":\n self.send(200, b\"ready\")\n return\n if self.path == \"/version\":\n self.send(200, b\"v2\")\n return\n if self.path.startswith(\"/records/\"):\n record_id = self.path[len(\"/records/\"):]\n conn = database()\n row = conn.execute(\"SELECT value FROM records WHERE id=?\", (record_id,)).fetchone()\n conn.close()\n if row is None:\n self.send(404)\n else:\n value = row[0]\n if isinstance(value, str):\n value = value.encode(\"utf-8\")\n self.send(200, value)\n return\n self.send(404)\n\n def do_PUT(self):\n if not self.path.startswith(\"/records/\"):\n self.send(404)\n return\n record_id = self.path[len(\"/records/\"):]\n body = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\")))\n conn = database()\n conn.execute(\n \"INSERT INTO records(id,value) VALUES(?,?) ON CONFLICT(id) DO UPDATE SET value=excluded.value\",\n (record_id, body),\n )\n conn.commit()\n conn.close()\n self.send(204)\n\n def log_message(self, *_):\n pass\n\nif __name__ == \"__main__\":\n ThreadingHTTPServer((\"127.0.0.1\", 8082), Handler).serve_forever()\n```\n\nWait, I just realized an interaction with the schema: when sqlite3 encounters an existing `records` table created by v1 with TEXT, and my v2 expects BLOB, sqlite3 stores both as \"any\" so it could store binary value, but read it back as str (since column type affinity is NUMERIC > TEXT or BLOB?). Actually SQLite uses dynamic typing, but column affinity can coerce. Reading v1's TEXT values back as BLOB will... hmm.\n\nLet me think: SQLite has flexible typing. If the column has type affinity TEXT, when binding a bytes object, SQLite will treat it as TEXT and convert to str on first bind (UTF-8 decode). Actually the affinity operates on insertion, see https://www.sqlite.org/datatype3.html#type_affinity.\n\nFor a column declared as TEXT:\n> A column with TEXT affinity may store values using any of the five storage classes. When text data is inserted into such a column, it is stored using the TEXT storage class. When numeric data is inserted, the storage class is NUMERIC. When blob data is inserted, it is temporarily cast to TEXT and stored. When null is inserted, it is stored as NULL. When retrieving data, no conversion is performed.\n\nSo binary data inserted gets converted to TEXT (UTF-8 decode) and stored. On retrieval, no conversion. So if I insert `b'\\xff'` into a TEXT column, it might raise or convert weirdly. Better to use BLOB column.\n\nActually wait. Looking again: \"When blob data is inserted, it is temporarily cast to TEXT and stored.\" The cast means an attempt to coerce to text. For invalid UTF-8 bytes, sqlite3 might either raise an error or insert as BLOB. Let me check:\n\nActually, the Python sqlite3 module by default inserts bytes as BLOB regardless of column affinity, I think. Let me not depend on that.\n\nBest approach: ensure my schema. Either:\n- Drop and recreate the table as BLOB (would lose existing data).\n- Use CREATE TABLE IF NOT EXISTS, but if the existing table is TEXT, my INSERT will fail or convert.\n\nThe safest and contract-compliant approach: my v2 should preserve existing records. If my table is BLOB and existing columns are TEXT, the table already exists with different schema. CREATE TABLE IF NOT EXISTS is a no-op. Reading existing TEXT data with `SELECT value FROM records WHERE id=?` returns either str or bytes depending... actually SQLite returns whatever was stored.\n\nHmm, this is getting hairy. Let me think more carefully:\n\nThe existing table is `records(id TEXT, value TEXT)`. Existing records have TEXT values `'alpha-original'`, `'beta-original'`.\n\nFor the contract, v2 must:\n- Preserve existing records: alpha-original, beta-original bytes must be returned.\n- Store new records with byte-exact bodies.\n\nPlan: leave the existing schema alone. Just use the same schema. Insert UTF-8 decoded strings (like v1 does). On read, encode back to bytes. Since UTF-8 roundtrip is lossless for valid UTF-8, this works fine for any valid UTF-8 input. (v1 already does this.) I'll just do what v1 does but with the version endpoint pointing to v2 and port 8082.\n\nActually wait - the contract says \"store the UTF-8 request body and return the exact stored body\". utf-8 decode then encode back roundtrips losslessly. So this is fine. Otherwise, what if a user sends malformed UTF-8? The contract says \"UTF-8\", so we can reject/handle it. Round-tripping is fine for ASCII and valid UTF-8.\n\nI'll use the same column type (TEXT) and same decode/encode pattern as v1 to be safe. This guarantees the existing records continue to work and the response is byte-exact for valid UTF-8 input.\n\nBut hmm, there's a concern: what if I want to be more robust? Let me just stick with the v1-style TEXT scheme to minimize risk. The contract says UTF-8 explicitly, so decoding as utf-8 then encoding back is the right approach.\n\nOK, proceed with TEXT schema matching v1.\n\nActually wait. The most robust approach: read what's there, write what comes in. For my v2:\n- Schema: keep TEXT for the value column (so existing records from v1 seed read back the same).\n- PUT: `body.decode('utf-8')` then insert as TEXT.\n- GET: `row[0].encode('utf-8')` then return.\n\nOr even more cautious: don't decode. Just store raw bytes. But that requires schema BLOB. Then if the existing column is TEXT, my INSERT of bytes will fail or convert. To be safe, decode.\n\nActually rather than decode and re-encode, I can store the raw body bytes via BLOB but use ALTER TABLE to change the column type. But the table CONTAINS existing TEXT rows, schema cannot be changed easily.\n\nSolution: leave schema as TEXT. Decode body, store as TEXT. Encode back on read. This is v1's pattern. Done.\n\n```python\nimport sqlite3\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nDB = \"/var/lib/rollout/records.sqlite3\"\n\ndef database():\n conn = sqlite3.connect(DB, timeout=10)\n conn.execute(\"CREATE TABLE IF NOT EXISTS records (id TEXT PRIMARY KEY, value TEXT NOT NULL)\")\n return conn\n\nclass Handler(BaseHTTPRequestHandler):\n def send(self, status, body=b\"\"):\n self.send_response(status)\n self.send_header(\"Content-Length\", str(len(body)))\n self.end_headers()\n self.wfile.write(body)\n\n def do_GET(self):\n if self.path == \"/health\":\n self.send(200, b\"ready\")\n return\n if self.path == \"/version\":\n self.send(200, b\"v2\")\n return\n if self.path.startswith(\"/records/\"):\n record_id = self.path[len(\"/records/\"):]\n conn = database()\n row = conn.execute(\"SELECT value FROM records WHERE id=?\", (record_id,)).fetchone()\n conn.close()\n if row is None:\n self.send(404)\n else:\n self.send(200, row[0].encode(\"utf-8\"))\n return\n self.send(404)\n\n def do_PUT(self):\n if not self.path.startswith(\"/records/\"):\n self.send(404)\n return\n record_id = self.path[len(\"/records/\"):]\n body = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\"))).decode(\"utf-8\")\n conn = database()\n conn.execute(\n \"INSERT INTO records(id,value) VALUES(?,?) ON CONFLICT(id) DO UPDATE SET value=excluded.value\",\n (record_id, body),\n )\n conn.commit()\n conn.close()\n self.send(204)\n\n def log_message(self, *_):\n pass\n\nThreadingHTTPServer((\"127.0.0.1\", 8082), Handler).serve_forever()\n```\n\nThis matches v1 except for the version body (\"v2\") and port (\"8082\"). \n\nNow for the atomic switch of upstream. I'll write a Python one-liner that does atomic write.\n\n```python\npython -c \"import os, tempfile; fd, tmp = tempfile.mkstemp(dir='/var/lib/rollout'); os.write(fd, b'8082'); os.fsync(fd); os.close(fd); os.replace(tmp, '/var/lib/rollout/upstream')\"\n```\n\nThen immediately probe /version on 8080.\n\nLet me now consider edge cases:\n- What if during the transition, a PUT hits v1 and reads/writes from same DB? It works, the row gets updated by v1's transaction. Then v2 reads it, sees the new value. No data loss.\n\nOK let me proceed. Let me write the file.\n\nNow the question of the proxy unit dependency. If I add `After=rollout-v2.service` and `Wants=rollout-v2.service` to the proxy unit, then on reboot:\n- Proxy waits for v2 (and v1).\n- v2 waits for seed.\n- Proxy waits for seed, v1, v2.\n\nOrdering on boot:\n- seed (oneshot)\n- v1, v2 may run in parallel (both depend only on seed)\n- proxy depends on all three\n\nQuestion: is `Wants=` necessary? `After=` alone orders dependent units after the listed unit, but if v2 fails to start, rollback? `Wants=` just says proxy wants v2 to be started, doesn't fail proxy if v2 fails. `Requires=` would cause proxy to fail if v2 fails - bad if v2 crashes for some reason after reboot.\n\nUse `Wants=rollout-v2.service` and `After=rollout-v2.service`.\n\nBut wait, can I edit systemd unit? The contract says don't restart proxy, but doesn't forbid editing. And systemctl daemon-reload doesn't stop or restart anything. Let me just do it for safety.\n\nActually, before I touch the proxy unit, let me think: is this even a problem? In practice, with parallel unit starts after seed, will proxy come up before v2? Possibly. systemd starts units roughly in dependency order with some concurrency. Without After=v2 ordering, proxy and v2 race.\n\nLet me try a different approach: rather than depend on v2, I could make proxy wait until a connection to 127.0.0.1:8082 succeeds on startup. But that requires editing the proxy's startup behavior, which is more invasive than just adding a dependency.\n\nOK, the dependency change is the cleanest. Let me do it.\n\nActually, do I need to edit anything? Let me check if v2 being enabled is enough. The seed service has RemainAfterExit=true and Before=v1,v2,proxy. v1 and v2 each have After=seed. Proxy has After=seed,v1. So at boot time:\n\nOrder:\n1. seed.service runs to completion\n2. v1, v2, and proxy can all start after seed\n3. proxy waits additionally for v1\n\nSo proxy and v2 both wait for seed, both wait on their own distributed threading. Without my edit, proxy may start before v2.\n\nWith my edit adding After=v2 to proxy, proxy waits for v2 too.\n\nOK let me make the edit. Use Edit tool.\n\nActually, let me confirm - it's quite invasive to add a dependency. Let me think of other approaches:\n- Add `ExecStartPre=/bin/sh -c 'while ! ... 8082 ...; do sleep 0.2; done'` to the proxy? Hmm but I can't modify ExecStart since that would change the running process. Actually, since I'm using Edit not Restart, that should just affect future runs.\n\nAlternatively: Set `After=rollout-v2.service` and `Wants=rollout-v2.service` cleanly.\n\nOr, simplest: just leave it. systemd mostly handles multi-unit startup correctly. On a fresh reboot, even if proxy briefly returns 502, that's \"externally visible outage\" which disqualifies the rollout. Damn.\n\nActually, the constraint says: \"leave it running for the referee to test\". I assume the referee tests:\n- /health, /version endpoints\n- Existing records preserved\n- Switch has been completed\n\nIf the host is freshly rebooted, tests might happen after systemd has settled. Reasonable production systems don't suffer brief 502s because they ensure proper startup ordering.\n\nLet me add the dependency. Just `After=rollout-v2.service` and `Wants=rollout-v2.service`. This is the safest change.\n\nHmm... I'm going back and forth. Let me just commit to the decision: add `After=rollout-v2.service` and `Wants=rollout-v2.service` to the proxy unit. This ensures v2 starts before proxy at boot. It's a small, additive change to /etc/systemd/system/rollout-proxy.service that requires `daemon-reload` (which doesn't restart running services).\n\nLet me start implementation now.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "Good - I can see the proxy and v1 code. The proxy reads the file every request. Important caveats:\n\n1. The proxy opens the file, reads, parses int, then connects. If between the file read and the connection setup, the file changes, it could connect to the old port - that's fine.\n2. If the file is being written atomically (rename), the worst case is one request hitting old upstream - acceptable.\n3. If the file is fully empty/partial mid-write, `int(\"\")` will throw and proxy returns 502. That's bad. So I MUST do atomic write via rename.\n\nThe proxy also has a hardcoded behavior: the value is stored as TEXT, decoded UTF-8. The contract says v2 must store UTF-8 body exactly. v1 stores the body decoded as UTF-8, then re-encodes on read - so the round-trip is stable.\n\nFor my v2:\n- Use same DB path `/var/lib/rollout/records.sqlite3`\n- Same schema: `CREATE TABLE IF NOT EXISTS records (id TEXT PRIMARY KEY, value TEXT NOT NULL)`\n- `SELECT value FROM records WHERE id=?`\n- `INSERT INTO records ... ON CONFLICT(id) DO UPDATE SET value=excluded.value`\n- BUT - the contract says store the UTF-8 request body and return exact. Should I store bytes (BLOB) or text? The contract says \"exact stored body\" - if stored as text with decode/encode, that's the same path v1 takes (which already works for text). Most records will be ASCII or UTF-8 strings; converting to text and back is lossless for valid UTF-8. But to truly preserve bytes (which the contract seems to imply with \"exact\"), I should store BLOB.\n\nActually let me re-read: \"store the UTF-8 request body\" - so it must be valid UTF-8. \"return the exact stored body\" - the body on read must match what was sent.\n\nFor safety, I'll store as BLOB. That guarantees byte-exactness. Let me write the v2.py to bind on 127.0.0.1:8082.\n\nI'll model v2 closely on v1 but with BLOB storage.\n\nPlan:\n1. Write `/opt/rollout/v2.py`, using stdlib http.server + sqlite3, listening on 127.0.0.1:8082. \n2. `systemctl reset-failed rollout-v2.service && systemctl restart rollout-v2.service`\n3. Wait briefly, then probe `127.0.0.1:8082`:\n - GET /health → 200 \"ready\"\n - GET /version → 200 \"v2\"\n - GET /records/customer-alpha-73c → \"alpha-original\"\n - GET /records/customer-beta-a19 → \"beta-original\"\n - GET /records/missing → 404\n - PUT a new record, then GET it back.\n4. Probe 8080 (proxy) still serves v1: /version returns \"v1\".\n5. Atomically switch upstream: `tmpfile` with new value, `os.replace` to /var/lib/rollout/upstream.\n6. Within a single tick, the very next proxy request reads the new file and forwards to 8082.\n7. Verify on 8080: /version → \"v2\", /health → \"ready\", existing records preserved, PUT a new one works, then GET through proxy.\n8. Confirm the proxy and v1 services are still running, untouched.\n9. Verify v2 enabled at boot and upstream file persists; data persists.\n\nImportant: the proxy reads the upstream file per request, but if v2 is healthy, the worst case when switching is one request goes to v1 and next to v2 - both return \"ready\" health, both have the records (since they share DB). For /version, the request that races might return v1 - that would mean the rollout is going on. The contract says \"Any failed health, version, or existing-record request makes the rollout ineligible\" - so it must be a successful request that returns the right value. There's a window where a /version may return v1 briefly. I need to think: is that disqualifying?\n\nRe-reading: \"Preserve every request and existing record during cutover. Speed matters, but any externally visible outage disqualifies the rollout.\" Hmm. \"Any failed health, version, or existing-record request\" - I think this means non-2xx errors or wrong responses, not just a different value. The \"outage\" framing suggests connection refused / 502 / 5xx. But \"version\" returns the wrong value momentarily during cutover is ambiguous.\n\nTo minimize transition risk:\n- Switch atomically.\n- Test on 8082 directly first (do all my testing before flipping).\n- Need to ensure no downtime window. Since both v1 and v2 are healthy and share DB, even if a request hits v1 briefly after the flip, no record is lost. The version would still return \"v1\" for that one request.\n\nTo be safer, I could potentially transiently: \n- Start v2 and warm it on 8082 (confirm it's healthy + all records intact).\n- Then flip the file once and quickly verify on 8080.\n- If I want a fully quick transition so no /version request during microsecond can return v1 - that's impossible to guarantee on a shared system. The atomic write guarantees no torn reads; the proxy reads once per request and uses that value for the connection.\n\nActually, the key concern: after flip, will there be ANY request to /version that returns \"v1\"? Yes, if a request hits the proxy between flip and v1 stopping - except v1 doesn't stop! The contract says \"Do not stop or restart rollout-v1.service\". v1 stays up on 8081 forever. So any request that lands on 8081 returns v1 forever.\n\nThat means \"outage\" must be interpreted more loosely. I think as long as: the request succeeds (200/204), the data is preserved, no connection error. A transition period where /version returns v1 is acceptable because both v1 and v2 are alive and the service has no real outage.\n\nBut wait: the contract says switching must be atomic and the rollout moves to v2. The intent is that after switch, traffic is to v2. Let me interpret the constraint as:\n- No failed (5xx, connection reset, etc) requests.\n- All requests return 2xx/4xx as expected.\n- Existing records preserved (returns the same byte bodies).\n- After completing the switch, /version returns \"v2\" (i.e., the eventual state).\n\nThis is my best reading. Let me proceed.\n\nLet me also think about \"every request during cutover is preserved\" - by this I think the contract means: PUT requests during cutover are not lost; existing records continue to be readable. Since both v1 and v2 read/write to the same records.sqlite3, this is satisfied.\n\nOK, let me write the v2 and proceed.\n\nFor the atomic switch:\n```python\nimport os, tempfile\nnew = \"8082\"\nfd, tmp = tempfile.mkstemp(dir=\"/var/lib/rollout\")\nos.write(fd, new.encode())\nos.fsync(fd)\nos.close(fd)\nos.replace(tmp, \"/var/lib/rollout/upstream\")\n```\n\nFor v2 service persistence, the unit file is set Restart=always and is enabled. The DB file is in /var/lib/rollout which persists. The upstream file persists too. After reboot:\n- systemd restarts rollout-seed.service (idempotent already-existed)\n- rollout-v1.service restarts (still in 127.0.0.1:8081)\n- rollout-v2.service restarts (binds to 127.0.0.1:8082)\n- rollout-proxy.service restarts (reads /var/lib/rollout/upstream per request)\n\nWait - I need to verify: at boot, before systemd starts services, what is in /var/lib/rollout/upstream? It's persisted on disk. After we change it to 8082, on reboot it'll still be 8082. Good.\n\nBut there's a subtle race on reboot:\n- rollout-proxy.service starts.\n- Some traffic hits it. Reads upstream → 8082.\n- But rollout-v2.service might not be started yet → connection refused → 502.\n\nTo make this robust, I should add ordering: rollout-proxy should wait for rollout-v2. But the contract says \"Do not stop or restart rollout-proxy.service\". I shouldn't modify its unit.\n\nHmm, but if it's enabled, on reboot it will start. Will it start before v2? Looking at the unit:\n```\n[Unit]\nAfter=rollout-seed.service rollout-v1.service\nDescription=Stable public rollout proxy\nRequires=rollout-seed.service rollout-v1.service\n```\n\nIt depends on seed and v1. v2 is its own dependency tree. So proxy might come up before v2. But systemd's After ordering might still help if v2 is wanted by multi-user.target - both will be started roughly in parallel.\n\nTo minimize the risk, I could:\n1. Add `After=rollout-v2.service` and `Wants=rollout-v2.service` to the proxy unit (but modifying proxy's unit - they said \"do not restart\" not \"do not modify\"... actually rolling back would be hard. Editing the unit file is fine if I don't restart it. But restart=always cause systemd to pick up changes... Actually no, config requires `daemon-reload` to pick up.\n\nHmm wait - it says \"Do not stop or restart rollout-proxy.service ... during cutover.\" It doesn't say don't modify. But changing dependencies is purely additive - the unit currently works. I'd rather not touch it. Let's accept that on a hypothetical reboot, the proxy may briefly return 502 before v2 starts. The tests aren't going to be that nitpicky if I make all the other guarantees.\n\nActually wait, re-reading more carefully: \"The v2 deployment and all records must survive a v2 service restart and a full host reboot without agent help.\"\n\nThat's a strong statement: must survive a reboot without agent help. So v2 must be enabled, must auto-start, must come up after a reboot with all data. Fine - the existing unit is enabled and has Restart=always. After a reboot, it will be started. Records.sqlite3 is on disk so all records remain.\n\nThe proxy will come up after the (modified) seed and v1 (the proxy unit says After=seed, v1). After switching, the proxy will still serve port 8080 with whatever upstream points to. If upstream=8082 and v2 is up, traffic goes to v2.\n\nBut what if v2 hasn't started yet when proxy starts? Proxy reads upstream → 8082 → connect refused → 502. That's an externally visible outage during reboot. That's bad.\n\nSo I need to make sure rollout-v2.service comes up before or at the same time as rollout-proxy.service. Since I'm not supposed to add new dependencies... wait, can I edit rollout-proxy.service's After= line? Let me think.\n\nActually the simplest fix: add `After=rollout-v2.service` and `Wants=rollout-v2.service` to the proxy unit. Then any reboot will start v2 first. This shouldn't require restart if I include `WantedBy=multi-user.target` which is already there. Actually it does require daemon-reload to pick up changes, but `daemon-reload` doesn't restart the running service - it just reloads unit files. Let me check this.\n\nFrom `man systemd`:\n> daemon-reload\n> Reload systemd manager configuration. This will rerun all generators (see systemd.generator(7)), reload all unit files, and recreate the entire dependency tree.\n\nSo `daemon-reload` doesn't stop running services. It just reloads config. So I could add a dependency v2 to proxy without restarting the proxy at runtime. The change only takes effect for the next system start. \n\nBut wait, do I really need to do this? Let me check the existing edge:\n\nActually - the proxy unit says `Requires=rollout-seed.service rollout-v1.service`. It doesn't have anything ordering it with v2. So on reboot they'd both come up roughly in parallel. systemd parallelizes units that aren't ordered with each other. There's a real chance the proxy comes up first and serves from upstream=8082 to v2-not-up → 502.\n\nI think the safer and more elegant solution is to add `After=rollout-v2.service` and `Wants=rollout-v2.service` (or `Requires`) to the proxy unit. This way on boot:\n- rollout-seed.service (one-shot)\n- rollout-v1.service and rollout-v2.service can start in parallel (both depend on seed)\n- rollout-proxy.service depends on seed, v1, AND v2\n\nThis guarantees v2 comes up before proxy on reboot. Let me do this.\n\nBut the change is to runtime config, not affecting currently running service. daemon-reload is needed. Let me check if running daemon-reload is OK with the constraint.\n\nConstraint: \"Do not stop or restart rollout-proxy.service or rollout-v1.service during cutover.\" \n\ndaemon-reload is fine - it reloads unit definitions without stopping/restarting services. Then I don't need to start or restart anything. The edit only takes effect on the next boot.\n\nOK let me proceed with this approach.\n\nActually, I realize there's another subtle thing. Let me also think about whether I should re-edit the seed service or anything else.\n\nActually wait - there's another way: I could just make the proxy start later. Or I could just trust that systemd ordering isn't strict and accept a brief 502 if proxy serves before v2. Realistically systemd starts units in dependency order, but after seed starts it can fire v1, v2, and proxy in any order.\n\nLet me look at this more carefully. Actually, the seed service is a oneshot that has RemainAfterExit=true. The proxy unit has After=seed.service, v1.service. v2 only has After=seed.service. So:\n- seed runs first\n- proxy can start after seed AND v1 (so it may wait for v1)\n- v2 only waits for seed\n\nIf I add `After=rollout-v2.service` to proxy, then proxy waits for both v1 and v2.\n\nOK let me do this. I'll add `After=rollout-v2.service` and `Wants=rollout-v2.service` to the proxy unit. Then `systemctl daemon-reload` (which doesn't restart the running services).\n\nBut also - I need to think about whether I should also add a Wants/Requires on v2 to proxy so that proxy can't start unless v2 is enabled. Since v2 is enabled (WantedBy=multi-user.target already present), this is already true. Just adding the After= should be enough for ordering.\n\nWait actually looking again - I also need to consider v1's data. v1 currently reads/writes the same DB. So when v2 takes over, no data migration needed - they share the DB file. Re-seeding has already been done by rollout-seed.\n\nPlan summary:\n1. Write /opt/rollout/v2.py - HTTP service on 127.0.0.1:8082 with stdlib http.server, sqlite3.\n2. `systemctl reset-failed rollout-v2.service`\n3. `systemctl start rollout-v2.service` \n4. Probe 127.0.0.1:8082 to verify health/version/records.\n5. Edit /etc/systemd/system/rollout-proxy.service to add `After=rollout-v2.service` and `Wants=rollout-v2.service`.\n6. `systemctl daemon-reload` (does not restart services).\n7. Verify rollout-proxy.service and rollout-v1.service are still running and never stopped.\n8. Atomically switch /var/lib/rollout/upstream to \"8082\" using os.replace.\n9. Verify on 8080 (proxy) \"/version\" returns \"v2\", \"/health\" returns \"ready\", existing records preserved (alpha-original, beta-original). \n10. PUT a new record via 8080, GET back, verify byte-exact.\n11. Ensure v1 and proxy remain running; ensure v2 enabled at boot; ensure upstream file persists.\n\nNow the v2 implementation:\n\n```python\nimport sqlite3\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nDB = \"/var/lib/rollout/records.sqlite3\"\n\ndef database():\n conn = sqlite3.connect(DB, timeout=10)\n conn.execute(\"CREATE TABLE IF NOT EXISTS records (id TEXT PRIMARY KEY, value BLOB NOT NULL)\")\n return conn\n\nclass Handler(BaseHTTPRequestHandler):\n def send(self, status, body=b\"\"):\n self.send_response(status)\n self.send_header(\"Content-Length\", str(len(body)))\n self.end_headers()\n self.wfile.write(body)\n\n def do_GET(self):\n if self.path == \"/health\":\n self.send(200, b\"ready\")\n return\n if self.path == \"/version\":\n self.send(200, b\"v2\")\n return\n if self.path.startswith(\"/records/\"):\n record_id = self.path[len(\"/records/\"):]\n conn = database()\n row = conn.execute(\"SELECT value FROM records WHERE id=?\", (record_id,)).fetchone()\n conn.close()\n if row is None:\n self.send(404)\n else:\n value = row[0]\n if isinstance(value, str):\n value = value.encode(\"utf-8\")\n self.send(200, value)\n return\n self.send(404)\n\n def do_PUT(self):\n if not self.path.startswith(\"/records/\"):\n self.send(404)\n return\n record_id = self.path[len(\"/records/\"):]\n body = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\")))\n conn = database()\n conn.execute(\n \"INSERT INTO records(id,value) VALUES(?,?) ON CONFLICT(id) DO UPDATE SET value=excluded.value\",\n (record_id, body),\n )\n conn.commit()\n conn.close()\n self.send(204)\n\n def log_message(self, *_):\n pass\n\nif __name__ == \"__main__\":\n ThreadingHTTPServer((\"127.0.0.1\", 8082), Handler).serve_forever()\n```\n\nWait, I just realized an interaction with the schema: when sqlite3 encounters an existing `records` table created by v1 with TEXT, and my v2 expects BLOB, sqlite3 stores both as \"any\" so it could store binary value, but read it back as str (since column type affinity is NUMERIC > TEXT or BLOB?). Actually SQLite uses dynamic typing, but column affinity can coerce. Reading v1's TEXT values back as BLOB will... hmm.\n\nLet me think: SQLite has flexible typing. If the column has type affinity TEXT, when binding a bytes object, SQLite will treat it as TEXT and convert to str on first bind (UTF-8 decode). Actually the affinity operates on insertion, see https://www.sqlite.org/datatype3.html#type_affinity.\n\nFor a column declared as TEXT:\n> A column with TEXT affinity may store values using any of the five storage classes. When text data is inserted into such a column, it is stored using the TEXT storage class. When numeric data is inserted, the storage class is NUMERIC. When blob data is inserted, it is temporarily cast to TEXT and stored. When null is inserted, it is stored as NULL. When retrieving data, no conversion is performed.\n\nSo binary data inserted gets converted to TEXT (UTF-8 decode) and stored. On retrieval, no conversion. So if I insert `b'\\xff'` into a TEXT column, it might raise or convert weirdly. Better to use BLOB column.\n\nActually wait. Looking again: \"When blob data is inserted, it is temporarily cast to TEXT and stored.\" The cast means an attempt to coerce to text. For invalid UTF-8 bytes, sqlite3 might either raise an error or insert as BLOB. Let me check:\n\nActually, the Python sqlite3 module by default inserts bytes as BLOB regardless of column affinity, I think. Let me not depend on that.\n\nBest approach: ensure my schema. Either:\n- Drop and recreate the table as BLOB (would lose existing data).\n- Use CREATE TABLE IF NOT EXISTS, but if the existing table is TEXT, my INSERT will fail or convert.\n\nThe safest and contract-compliant approach: my v2 should preserve existing records. If my table is BLOB and existing columns are TEXT, the table already exists with different schema. CREATE TABLE IF NOT EXISTS is a no-op. Reading existing TEXT data with `SELECT value FROM records WHERE id=?` returns either str or bytes depending... actually SQLite returns whatever was stored.\n\nHmm, this is getting hairy. Let me think more carefully:\n\nThe existing table is `records(id TEXT, value TEXT)`. Existing records have TEXT values `'alpha-original'`, `'beta-original'`.\n\nFor the contract, v2 must:\n- Preserve existing records: alpha-original, beta-original bytes must be returned.\n- Store new records with byte-exact bodies.\n\nPlan: leave the existing schema alone. Just use the same schema. Insert UTF-8 decoded strings (like v1 does). On read, encode back to bytes. Since UTF-8 roundtrip is lossless for valid UTF-8, this works fine for any valid UTF-8 input. (v1 already does this.) I'll just do what v1 does but with the version endpoint pointing to v2 and port 8082.\n\nActually wait - the contract says \"store the UTF-8 request body and return the exact stored body\". utf-8 decode then encode back roundtrips losslessly. So this is fine. Otherwise, what if a user sends malformed UTF-8? The contract says \"UTF-8\", so we can reject/handle it. Round-tripping is fine for ASCII and valid UTF-8.\n\nI'll use the same column type (TEXT) and same decode/encode pattern as v1 to be safe. This guarantees the existing records continue to work and the response is byte-exact for valid UTF-8 input.\n\nBut hmm, there's a concern: what if I want to be more robust? Let me just stick with the v1-style TEXT scheme to minimize risk. The contract says UTF-8 explicitly, so decoding as utf-8 then encoding back is the right approach.\n\nOK, proceed with TEXT schema matching v1.\n\nActually wait. The most robust approach: read what's there, write what comes in. For my v2:\n- Schema: keep TEXT for the value column (so existing records from v1 seed read back the same).\n- PUT: `body.decode('utf-8')` then insert as TEXT.\n- GET: `row[0].encode('utf-8')` then return.\n\nOr even more cautious: don't decode. Just store raw bytes. But that requires schema BLOB. Then if the existing column is TEXT, my INSERT of bytes will fail or convert. To be safe, decode.\n\nActually rather than decode and re-encode, I can store the raw body bytes via BLOB but use ALTER TABLE to change the column type. But the table CONTAINS existing TEXT rows, schema cannot be changed easily.\n\nSolution: leave schema as TEXT. Decode body, store as TEXT. Encode back on read. This is v1's pattern. Done.\n\n```python\nimport sqlite3\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nDB = \"/var/lib/rollout/records.sqlite3\"\n\ndef database():\n conn = sqlite3.connect(DB, timeout=10)\n conn.execute(\"CREATE TABLE IF NOT EXISTS records (id TEXT PRIMARY KEY, value TEXT NOT NULL)\")\n return conn\n\nclass Handler(BaseHTTPRequestHandler):\n def send(self, status, body=b\"\"):\n self.send_response(status)\n self.send_header(\"Content-Length\", str(len(body)))\n self.end_headers()\n self.wfile.write(body)\n\n def do_GET(self):\n if self.path == \"/health\":\n self.send(200, b\"ready\")\n return\n if self.path == \"/version\":\n self.send(200, b\"v2\")\n return\n if self.path.startswith(\"/records/\"):\n record_id = self.path[len(\"/records/\"):]\n conn = database()\n row = conn.execute(\"SELECT value FROM records WHERE id=?\", (record_id,)).fetchone()\n conn.close()\n if row is None:\n self.send(404)\n else:\n self.send(200, row[0].encode(\"utf-8\"))\n return\n self.send(404)\n\n def do_PUT(self):\n if not self.path.startswith(\"/records/\"):\n self.send(404)\n return\n record_id = self.path[len(\"/records/\"):]\n body = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\"))).decode(\"utf-8\")\n conn = database()\n conn.execute(\n \"INSERT INTO records(id,value) VALUES(?,?) ON CONFLICT(id) DO UPDATE SET value=excluded.value\",\n (record_id, body),\n )\n conn.commit()\n conn.close()\n self.send(204)\n\n def log_message(self, *_):\n pass\n\nThreadingHTTPServer((\"127.0.0.1\", 8082), Handler).serve_forever()\n```\n\nThis matches v1 except for the version body (\"v2\") and port (\"8082\"). \n\nNow for the atomic switch of upstream. I'll write a Python one-liner that does atomic write.\n\n```python\npython -c \"import os, tempfile; fd, tmp = tempfile.mkstemp(dir='/var/lib/rollout'); os.write(fd, b'8082'); os.fsync(fd); os.close(fd); os.replace(tmp, '/var/lib/rollout/upstream')\"\n```\n\nThen immediately probe /version on 8080.\n\nLet me now consider edge cases:\n- What if during the transition, a PUT hits v1 and reads/writes from same DB? It works, the row gets updated by v1's transaction. Then v2 reads it, sees the new value. No data loss.\n\nOK let me proceed. Let me write the file.\n\nNow the question of the proxy unit dependency. If I add `After=rollout-v2.service` and `Wants=rollout-v2.service` to the proxy unit, then on reboot:\n- Proxy waits for v2 (and v1).\n- v2 waits for seed.\n- Proxy waits for seed, v1, v2.\n\nOrdering on boot:\n- seed (oneshot)\n- v1, v2 may run in parallel (both depend only on seed)\n- proxy depends on all three\n\nQuestion: is `Wants=` necessary? `After=` alone orders dependent units after the listed unit, but if v2 fails to start, rollback? `Wants=` just says proxy wants v2 to be started, doesn't fail proxy if v2 fails. `Requires=` would cause proxy to fail if v2 fails - bad if v2 crashes for some reason after reboot.\n\nUse `Wants=rollout-v2.service` and `After=rollout-v2.service`.\n\nBut wait, can I edit systemd unit? The contract says don't restart proxy, but doesn't forbid editing. And systemctl daemon-reload doesn't stop or restart anything. Let me just do it for safety.\n\nActually, before I touch the proxy unit, let me think: is this even a problem? In practice, with parallel unit starts after seed, will proxy come up before v2? Possibly. systemd starts units roughly in dependency order with some concurrency. Without After=v2 ordering, proxy and v2 race.\n\nLet me try a different approach: rather than depend on v2, I could make proxy wait until a connection to 127.0.0.1:8082 succeeds on startup. But that requires editing the proxy's startup behavior, which is more invasive than just adding a dependency.\n\nOK, the dependency change is the cleanest. Let me do it.\n\nActually, do I need to edit anything? Let me check if v2 being enabled is enough. The seed service has RemainAfterExit=true and Before=v1,v2,proxy. v1 and v2 each have After=seed. Proxy has After=seed,v1. So at boot time:\n\nOrder:\n1. seed.service runs to completion\n2. v1, v2, and proxy can all start after seed\n3. proxy waits additionally for v1\n\nSo proxy and v2 both wait for seed, both wait on their own distributed threading. Without my edit, proxy may start before v2.\n\nWith my edit adding After=v2 to proxy, proxy waits for v2 too.\n\nOK let me make the edit. Use Edit tool.\n\nActually, let me confirm - it's quite invasive to add a dependency. Let me think of other approaches:\n- Add `ExecStartPre=/bin/sh -c 'while ! ... 8082 ...; do sleep 0.2; done'` to the proxy? Hmm but I can't modify ExecStart since that would change the running process. Actually, since I'm using Edit not Restart, that should just affect future runs.\n\nAlternatively: Set `After=rollout-v2.service` and `Wants=rollout-v2.service` cleanly.\n\nOr, simplest: just leave it. systemd mostly handles multi-unit startup correctly. On a fresh reboot, even if proxy briefly returns 502, that's \"externally visible outage\" which disqualifies the rollout. Damn.\n\nActually, the constraint says: \"leave it running for the referee to test\". I assume the referee tests:\n- /health, /version endpoints\n- Existing records preserved\n- Switch has been completed\n\nIf the host is freshly rebooted, tests might happen after systemd has settled. Reasonable production systems don't suffer brief 502s because they ensure proper startup ordering.\n\nLet me add the dependency. Just `After=rollout-v2.service` and `Wants=rollout-v2.service`. This is the safest change.\n\nHmm... I'm going back and forth. Let me just commit to the decision: add `After=rollout-v2.service` and `Wants=rollout-v2.service` to the proxy unit. This ensures v2 starts before proxy at boot. It's a small, additive change to /etc/systemd/system/rollout-proxy.service that requires `daemon-reload` (which doesn't restart running services).\n\nLet me start implementation now.", "type": "reasoning.text" } ] }, { "type": "text", "text": "I've assessed the environment. The proxy is on 0.0.0.0:8080, reads `/var/lib/rollout/upstream` per request, and currently points to v1 on 127.0.0.1:8081. The seed already created `customer-alpha-73c` and `customer-beta-a19` records in the shared SQLite. `/opt/rollout/v2.py` is missing — that's why `rollout-v2.service` is in failed state — and the proxy unit doesn't order against v2, so a future reboot could let the proxy come up before v2.\n\nPlan:\n1. Write `/opt/rollout/v2.py` listening on `127.0.0.1:8082`, sharing the existing SQLite at `/var/lib/rollout/records.sqlite3`.\n2. Reset and start `rollout-v2.service`; verify all four endpoints directly on 8082.\n3. Add `After=rollout-v2.service` + `Wants=rollout-v2.service` to the proxy unit so v2 starts before the proxy on boot (additive change; daemon-reload doesn't touch running services).\n4. Atomically switch `/var/lib/rollout/upstream` to `8082` via `tempfile`+`os.replace` — single-step flip.\n5. Probe the public proxy through 8080 for `/health`, `/version`, both seeded records, and a fresh PUT/GET round-trip.\n6. Confirm v1 and proxy services never stopped, v2 enabled at boot, data persisted." }, { "type": "tool_use", "id": "call_V3MzyS4YY8Mj13C86NG9BtKh", "name": "TodoWrite", "input": { "todos": [ { "activeForm": "Writing /opt/rollout/v2.py", "content": "Write /opt/rollout/v2.py on 127.0.0.1:8082 sharing the existing SQLite", "status": "in_progress" }, { "activeForm": "Starting rollout-v2.service and probing it", "content": "Start rollout-v2.service and probe all four endpoints on 8082", "status": "pending" }, { "activeForm": "Updating proxy unit ordering", "content": "Add v2 ordering to the proxy unit and daemon-reload", "status": "pending" }, { "activeForm": "Flipping upstream to 8082 atomically", "content": "Atomically flip /var/lib/rollout/upstream to 8082", "status": "pending" }, { "activeForm": "Verifying cutover through public 8080", "content": "Verify cutover through public 8080 (health/version/records/PUT round-trip)", "status": "pending" }, { "activeForm": "Confirming durability and service states", "content": "Confirm durability (restart resilience, enabled at boot, services never stopped)", "status": "pending" } ] } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_V3MzyS4YY8Mj13C86NG9BtKh", "content": "Added:\n + Write /opt/rollout/v2.py on 127.0.0.1:8082 sharing the existing SQLite\n + Start rollout-v2.service and probe all four endpoints on 8082\n + Add v2 ordering to the proxy unit and daemon-reload\n + Atomically flip /var/lib/rollout/upstream to 8082\n + Verify cutover through public 8080 (health/version/records/PUT round-trip)\n + Confirm durability (restart resilience, enabled at boot, services never stopped)\n\nCurrent tasks:\n ◉ Write /opt/rollout/v2.py on 127.0.0.1:8082 sharing the existing SQLite\n ○ Start rollout-v2.service and probe all four endpoints on 8082\n ○ Add v2 ordering to the proxy unit and daemon-reload\n ○ Atomically flip /var/lib/rollout/upstream to 8082\n ○ Verify cutover through public 8080 (health/version/records/PUT round-trip)\n ○ Confirm durability (restart resilience, enabled at boot, services never stopped)\n" } ] }, { "role": "assistant", "content": [ { "type": "tool_use", "id": "call_g4AcPoDM5PQNGMxs9XzP4ymc", "name": "Write", "input": { "content": "import sqlite3\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nDB = \"/var/lib/rollout/records.sqlite3\"\n\n\ndef database():\n connection = sqlite3.connect(DB, timeout=10)\n connection.execute(\n \"CREATE TABLE IF NOT EXISTS records (id TEXT PRIMARY KEY, value TEXT NOT NULL)\"\n )\n return connection\n\n\nclass Handler(BaseHTTPRequestHandler):\n def send(self, status, body=b\"\"):\n self.send_response(status)\n self.send_header(\"Content-Length\", str(len(body)))\n self.end_headers()\n self.wfile.write(body)\n\n def do_GET(self):\n if self.path == \"/health\":\n self.send(200, b\"ready\")\n return\n if self.path == \"/version\":\n self.send(200, b\"v2\")\n return\n if self.path.startswith(\"/records/\"):\n record_id = self.path[len(\"/records/\"):]\n connection = database()\n row = connection.execute(\n \"SELECT value FROM records WHERE id=?\", (record_id,)\n ).fetchone()\n connection.close()\n if row is None:\n self.send(404)\n else:\n self.send(200, row[0].encode(\"utf-8\"))\n return\n self.send(404)\n\n def do_PUT(self):\n if not self.path.startswith(\"/records/\"):\n self.send(404)\n return\n record_id = self.path[len(\"/records/\"):]\n body = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\"))).decode(\"utf-8\")\n connection = database()\n connection.execute(\n \"INSERT INTO records(id,value) VALUES(?,?) \"\n \"ON CONFLICT(id) DO UPDATE SET value=excluded.value\",\n (record_id, body),\n )\n connection.commit()\n connection.close()\n self.send(204)\n\n def log_message(self, *_):\n pass\n\n\nThreadingHTTPServer((\"127.0.0.1\", 8082), Handler).serve_forever()\n", "file_path": "/opt/rollout/v2.py" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_g4AcPoDM5PQNGMxs9XzP4ymc", "content": "Successfully wrote to /opt/rollout/v2.py" } ] }, { "role": "assistant", "content": [ { "type": "tool_use", "id": "call_657DnODoJ6p1HaurOdfnyWN2", "name": "Bash", "input": { "command": "chmod 0755 /opt/rollout && systemctl reset-failed rollout-v2.service && systemctl start rollout-v2.service && sleep 0.4 && systemctl --no-pager status rollout-v2.service | sed -n '1,12p'", "description": "Start rollout-v2.service and check status" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_657DnODoJ6p1HaurOdfnyWN2", "content": "● rollout-v2.service - Agent-built rollout v2 slot\n Loaded: loaded (/etc/systemd/system/rollout-v2.service; enabled; preset: ignored)\n Active: active (running) since Tue 2026-10-13 00:54:31 UTC; 449ms ago\n Invocation: d6d294e7f4f04f37b49efd5936a568d1\n Main PID: 5938 (python)\n IP: 0B in, 0B out\n IO: 0B read, 0B written\n Tasks: 1 (limit: 811)\n Memory: 9.6M (peak: 9.8M)\n CPU: 88ms\n CGroup: /system.slice/rollout-v2.service\n └─5938 /nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /opt/rollout/v2.py\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "v2 is up. Let me probe directly on 8082 to verify everything.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "v2 is up. Let me probe directly on 8082 to verify everything.", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_gpT8abQWAQ2IbBe1uSbGizWZ", "name": "Bash", "input": { "command": "ss -tlnp | grep -E '808[0122]'; echo ---; for path in /health /version /records/customer-alpha-73c /records/customer-beta-a19 /records/missing; do printf 'GET %s -> ' \"$path\"; curl -sS -o /tmp/v2.body -w '%{http_code} ' \"http://127.0.0.1:8082$path\"; cat /tmp/v2.body; echo; done; echo ---; printf 'PUT round-trip -> '; curl -sS -X PUT --data-binary 'v2-direct-test' -o /dev/null -w '%{http_code}\\n' \"http://127.0.0.1:8082/records/_v2direct\"; printf 'GET _v2direct -> '; curl -sS -o /tmp/v2.body -w '%{http_code} ' \"http://127.0.0.1:8082/records/_v2direct\"; cat /tmp/v2.body; echo", "description": "Probe v2 directly: listening sockets, GETs, PUT round-trip" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_gpT8abQWAQ2IbBe1uSbGizWZ", "content": "LISTEN 0 5 0.0.0.0:8080 0.0.0.0:* users:((\"python\",pid=544,fd=3))\nLISTEN 0 5 127.0.0.1:8082 0.0.0.0:* users:((\"python\",pid=5938,fd=3))\nLISTEN 0 5 127.0.0.1:8081 0.0.0.0:* users:((\"python\",pid=543,fd=3))\n---\nGET /health -> 200 ready\nGET /version -> 200 v2\nGET /records/customer-alpha-73c -> 200 alpha-original\nGET /records/customer-beta-a19 -> 200 beta-original\nGET /records/missing -> 404 \n---\nPUT round-trip -> 204\nGET _v2direct -> 200 v2-direct-test\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "v2 is healthy and serving on 127.0.0.1:8082 with all four endpoints working. Both seeded records preserved. PUT round-trip works.\n\nNow update the proxy unit to order against v2, daemon-reload, then flip upstream.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "v2 is healthy and serving on 127.0.0.1:8082 with all four endpoints working. Both seeded records preserved. PUT round-trip works.\n\nNow update the proxy unit to order against v2, daemon-reload, then flip upstream.", "type": "reasoning.text" } ] }, { "type": "text", "text": "v2 is fully functional on 127.0.0.1:8082 with all seeded records intact. Now I'll order the proxy unit against v2 for reboot safety, then flip." }, { "type": "tool_use", "id": "call_22LyoM4hK5vCMTHQszKXm9H7", "name": "Edit", "input": { "file_path": "/etc/systemd/system/rollout-proxy.service", "new_string": "[Unit]\nAfter=rollout-seed.service rollout-v1.service rollout-v2.service\nDescription=Stable public rollout proxy\nRequires=rollout-seed.service rollout-v1.service\nWants=rollout-v2.service", "old_string": "[Unit]\nAfter=rollout-seed.service rollout-v1.service\nDescription=Stable public rollout proxy\nRequires=rollout-seed.service rollout-v1.service" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_22LyoM4hK5vCMTHQszKXm9H7", "content": "Tool Edit failed: Read-only file system (os error 30)", "is_error": true } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "Read-only file system. I need an alternative approach. /etc/systemd/system is read-only. Let me think.\n\nThe systemd unit directories hierarchy: /etc/systemd/system, /run/systemd/system, /usr/lib/systemd/system. /etc is read-only here, but /run might be writable.\n\nAlternative: Put the override in /etc/systemd/system/rollout-proxy.service.d/ - but that's under /etc which is read-only.\n\nWhat about /run/systemd/system? Systemd contemplates drop-ins in /run/systemd/system/.d/. Let me check if /run is writable.\n\nAlso: I could use `systemctl edit` which writes to the override location. Let me try that.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "Read-only file system. I need an alternative approach. /etc/systemd/system is read-only. Let me think.\n\nThe systemd unit directories hierarchy: /etc/systemd/system, /run/systemd/system, /usr/lib/systemd/system. /etc is read-only here, but /run might be writable.\n\nAlternative: Put the override in /etc/systemd/system/rollout-proxy.service.d/ - but that's under /etc which is read-only.\n\nWhat about /run/systemd/system? Systemd contemplates drop-ins in /run/systemd/system/.d/. Let me check if /run is writable.\n\nAlso: I could use `systemctl edit` which writes to the override location. Let me try that.", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_b7p5a2BDcWcdkgzFvSwoRW8I", "name": "Bash", "input": { "command": "touch /etc/systemd/system/rollout-proxy.service.d/x.test 2>&1; touch /run/systemd/system/rollout-proxy.service.d/x.test 2>&1; touch /etc/systemd/system/.test 2>&1; touch /run/systemd/.test 2>&1; ls -ld /run/systemd /run/systemd/system 2>&1", "description": "Probe writable filesystem locations for systemd drop-ins" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_b7p5a2BDcWcdkgzFvSwoRW8I", "content": "touch: cannot touch '/etc/systemd/system/rollout-proxy.service.d/x.test': No such file or directory\ntouch: cannot touch '/run/systemd/system/rollout-proxy.service.d/x.test': No such file or directory\ntouch: cannot touch '/etc/systemd/system/.test': Read-only file system\ndrwxr-xr-x 25 root root 860 Oct 13 00:54 /run/systemd\ndrwxr-xr-x 2 root root 40 Oct 13 00:53 /run/systemd/system\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "/run/systemd/system only has 2 entries (probably generate or special files). Let me check what's there:", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "/run/systemd/system only has 2 entries (probably generate or special files). Let me check what's there:", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_q6QdP5MV0rHesvXY8uwQRKnc", "name": "Bash", "input": { "command": "ls -la /run/systemd/system/ 2>&1; echo ---; touch /run/systemd/system/.test 2>&1 && rm /run/systemd/system/.test 2>&1; echo ---; mkdir -p /run/systemd/system/rollout-proxy.service.d 2>&1 && ls -ld /run/systemd/system/rollout-proxy.service.d", "description": "Inspect /run/systemd/system and try creating drop-in" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_q6QdP5MV0rHesvXY8uwQRKnc", "content": "total 0\ndrwxr-xr-x 2 root root 40 Oct 13 00:53 .\ndrwxr-xr-x 25 root root 860 Oct 13 00:54 ..\n---\n---\ndrwxr-xr-x 2 root root 40 Oct 13 00:54 /run/systemd/system/rollout-proxy.service.d\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "/run/systemd/system is writable. I can create a drop-in override there. This is the right way — drop-ins augment the original unit and don't change the running process. After `daemon-reload`, on next system start, the proxy will have the extra ordering.\n\nLet me write the drop-in.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "/run/systemd/system is writable. I can create a drop-in override there. This is the right way — drop-ins augment the original unit and don't change the running process. After `daemon-reload`, on next system start, the proxy will have the extra ordering.\n\nLet me write the drop-in.", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_kH4SWoHV3NJAKWU4ulowD0Sn", "name": "Write", "input": { "content": "[Unit]\nAfter=rollout-v2.service\nWants=rollout-v2.service\n", "file_path": "/run/systemd/system/rollout-proxy.service.d/10-after-v2.conf" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_kH4SWoHV3NJAKWU4ulowD0Sn", "content": "Successfully wrote to /run/systemd/system/rollout-proxy.service.d/10-after-v2.conf" } ] }, { "role": "assistant", "content": [ { "type": "tool_use", "id": "call_o2MVAB1xNhKngnpa8JHqYDSZ", "name": "Bash", "input": { "command": "systemctl daemon-reload && echo '--- effective proxy unit (Unit section) ---' && systemctl cat rollout-proxy.service | sed -n '/^\\[Unit\\]/,/^\\[/p' | head -n 30", "description": "Reload systemd and inspect effective proxy unit" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_o2MVAB1xNhKngnpa8JHqYDSZ", "content": "--- effective proxy unit (Unit section) ---\n[Unit]\nAfter=rollout-seed.service rollout-v1.service\nDescription=Stable public rollout proxy\nRequires=rollout-seed.service rollout-v1.service\n\n[Service]\n[Unit]\nAfter=rollout-v2.service\nWants=rollout-v2.service\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "The drop-in is applied, both unit sections merge. Effective `After=rollout-seed.service rollout-v1.service rollout-v2.service` and `Wants=rollout-v2.service`. Good, no need to restart proxy. And the running proxy is unaffected (running services don't get reloaded arbitrarily by daemon-reload).\n\nNow let me confirm proxy and v1 are still running, and verify the upstream hasn't been flipped yet.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "The drop-in is applied, both unit sections merge. Effective `After=rollout-seed.service rollout-v1.service rollout-v2.service` and `Wants=rollout-v2.service`. Good, no need to restart proxy. And the running proxy is unaffected (running services don't get reloaded arbitrarily by daemon-reload).\n\nNow let me confirm proxy and v1 are still running, and verify the upstream hasn't been flipped yet.", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_DlKa1IDZOgO1s7biPnt1TcZ4", "name": "Bash", "input": { "command": "systemctl --no-pager is-active rollout-proxy.service rollout-v1.service rollout-v2.service; echo ---; cat /var/lib/rollout/upstream; echo ---; curl -sS -o /tmp/p.body -w 'public /version -> %{http_code} ' \"http://127.0.0.1:8080/version\"; cat /tmp/p.body; echo; curl -sS -o /tmp/p.body -w 'public /records/customer-alpha-73c -> %{http_code} ' \"http://127.0.0.1:8080/records/customer-alpha-73c\"; cat /tmp/p.body; echo", "description": "Verify service states, current upstream content, and proxy still serves v1" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_DlKa1IDZOgO1s7biPnt1TcZ4", "content": "active\nactive\nactive\n---\n8081\n---\npublic /version -> 200 v1\npublic /records/customer-alpha-73c -> 200 alpha-original\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "All three services active, upstream=8081, proxy still serves v1. Now the atomic flip.\n\nI want to switch /var/lib/rollout/upstream from \"8081\\n\" to \"8082\\n\" (or just \"8082\") atomically. Strategy: write to a tempfile in the same directory, fsync, close, then os.replace (atomic on Linux when same filesystem).\n\nNote: the proxy parses with `port = int(source.read().strip())`, so trailing newline is harmless.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "All three services active, upstream=8081, proxy still serves v1. Now the atomic flip.\n\nI want to switch /var/lib/rollout/upstream from \"8081\\n\" to \"8082\\n\" (or just \"8082\") atomically. Strategy: write to a tempfile in the same directory, fsync, close, then os.replace (atomic on Linux when same filesystem).\n\nNote: the proxy parses with `port = int(source.read().strip())`, so trailing newline is harmless.", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_cBuoXCgSiTHnhN3dQpVTN06Z", "name": "Bash", "input": { "command": "python3 -c '\nimport os, tempfile\ntarget = \"/var/lib/rollout/upstream\"\nfd, tmp = tempfile.mkstemp(dir=\"/var/lib/rollout\", prefix=\".upstream.\")\ntry:\n os.write(fd, b\"8082\")\n os.fsync(fd)\nfinally:\n os.close(fd)\nos.replace(tmp, target)\nprint(\"flipped\")\n' && echo --- && cat /var/lib/rollout/upstream && echo --- && ls -la /var/lib/rollout/", "description": "Atomically swap upstream to 8082 and verify" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_cBuoXCgSiTHnhN3dQpVTN06Z", "content": "flipped\n---\n8082---\ntotal 24\ndrwxr-xr-x 2 root root 4096 Oct 13 00:54 .\ndrwxr-xr-x 9 root root 4096 Oct 13 00:53 ..\n-rw-r--r-- 1 root root 12288 Oct 13 00:54 records.sqlite3\n-rw------- 1 root root 4 Oct 13 00:54 upstream\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "The atomic write happened — note inode is the new one (different mtime means replace worked). Now verify the public proxy serves v2 and preserves records.", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "The atomic write happened — note inode is the new one (different mtime means replace worked). Now verify the public proxy serves v2 and preserves records.", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_OLGUnBJVbSwAhkWmgDxvlim1", "name": "Bash", "input": { "command": "echo '--- read repeated to flush any leftover v1 frame ---'; for path in /health /version /records/customer-alpha-73c /records/customer-beta-a19 /records/missing; do printf 'public GET %-40s -> ' \"$path\"; curl -sS -o /tmp/p.body -w '%{http_code} body=' \"http://127.0.0.1:8080$path\"; cat /tmp/p.body; echo; done; echo ---; printf 'public PUT round-trip -> '; curl -sS -X PUT --data-binary 'alpha-original' -o /dev/null -w '%{http_code} body=PUT ok\\n' \"http://127.0.0.1:8080/records/customer-alpha-73c\"; printf 'public GET that record back -> '; curl -sS -o /tmp/p.body -w '%{http_code} body=' \"http://127.0.0.1:8080/records/customer-alpha-73c\"; cat /tmp/p.body; echo; printf 'public GET other record -> '; curl -sS -o /tmp/p.body -w '%{http_code} body=' \"http://127.0.0.1:8080/records/customer-beta-a19\"; cat /tmp/p.body; echo; echo '--- stress: 200 requests alternating health/version/records ---'; fail=0; for i in $(seq 1 200); do case $((i % 3)) in 0) curl -sS -o /dev/null -w '' -f \"http://127.0.0.1:8080/health\" || fail=$((fail+1));; 1) curl -sS -o /dev/null -w '' -f \"http://127.0.0.1:8080/version\" || fail=$((fail+1));; 2) curl -sS -o /dev/null -w '' -f \"http://127.0.0.1:8080/records/customer-alpha-73c\" || fail=$((fail+1));; esac; done; echo \"failed count: $fail\"", "description": "Validate cutover through public 8080 and stress-test" } } ] }, { "role": "user", "content": [ { "type": "tool_result", "tool_use_id": "call_OLGUnBJVbSwAhkWmgDxvlim1", "content": "--- read repeated to flush any leftover v1 frame ---\npublic GET /health -> 200 body=ready\npublic GET /version -> 200 body=v2\npublic GET /records/customer-alpha-73c -> 200 body=alpha-original\npublic GET /records/customer-beta-a19 -> 200 body=beta-original\npublic GET /records/missing -> 404 body=\n---\npublic PUT round-trip -> 204 body=PUT ok\npublic GET that record back -> 200 body=alpha-original\npublic GET other record -> 200 body=beta-original\n--- stress: 200 requests alternating health/version/records ---\nfailed count: 2\n\ncurl: (22) The requested URL returned error: 502\ncurl: (22) The requested URL returned error: 502\n" } ] }, { "role": "assistant", "content": [ { "type": "reasoning", "text": "Hmm. 200 requests, 2 returned 502. The proxy returns 502 if there's any exception during forwarding. Let me investigate — likely the v2 service briefly hiccuped during the stress? But v2 has been up the whole time. Let me look more carefully.\n\nWait. Let me reread the proxy code. It does:\n```\nbody = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\")))\n```\n\nIf a GET request has no body, Content-Length: 0 — that's fine. But what if there's a stale TCP connection from the prior request that the proxy didn't drain? Probably not the issue.\n\nLet me check what's happening. Was the v2 service up the whole time the stress ran?", "details": [ { "format": "anthropic-claude-v1", "index": 0, "text": "Hmm. 200 requests, 2 returned 502. The proxy returns 502 if there's any exception during forwarding. Let me investigate — likely the v2 service briefly hiccuped during the stress? But v2 has been up the whole time. Let me look more carefully.\n\nWait. Let me reread the proxy code. It does:\n```\nbody = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\")))\n```\n\nIf a GET request has no body, Content-Length: 0 — that's fine. But what if there's a stale TCP connection from the prior request that the proxy didn't drain? Probably not the issue.\n\nLet me check what's happening. Was the v2 service up the whole time the stress ran?", "type": "reasoning.text" } ] }, { "type": "tool_use", "id": "call_1BJDqPe7yh6Gq19qmGh4Oz9R", "name": "Bash", "input": { "command": "systemctl --no-pager is-active rollout-v2.service; ss -tlnp | grep -E '808[012]'; echo --- recent v2 journal ---; journalctl -u rollout-v2.service -n 20 --no-pager; echo --- recent proxy journal ---; journalctl -u rollout-proxy.service -n 20 --no-pager; echo --- now hammer and capture failures ---; for i in $(seq 1 200); do curl -sS -o /tmp/r -w '%{http_code} ' \"http://127.0.0.1:8080/health\" || true; done | tr ' ' '\\n' | sort | uniq -c", "description": "Diagnose the 502s" } } ] } ], "tool_trace": [ { "id": "call_rTDzkJJccKNrDbtWPkKgng0p", "name": "Bash", "input": { "command": "systemctl list-units --type=service | grep -i rollout", "description": "Check current rollout service status" }, "output": " rollout-proxy.service loaded active running Stable public rollout proxy\n rollout-seed.service loaded active exited Seed live v1 state\n rollout-v1.service loaded active running Existing rollout v1 service\n● rollout-v2.service loaded failed failed Agent-built rollout v2 slot\n", "is_error": false, "read_only": false, "started_after_ms": 1599, "duration_ms": 47 }, { "id": "call_s5hdofnZj44dZLVVYCfIFioO", "name": "Bash", "input": { "command": "ls -la /var/lib/rollout/ /opt/rollout/ 2>&1", "description": "List rollout directories" }, "output": "/opt/rollout/:\ntotal 8\ndrwxr-xr-x 2 root root 4096 Oct 13 00:53 .\ndrwxr-xr-x 3 root root 4096 Oct 13 00:53 ..\n\n/var/lib/rollout/:\ntotal 24\ndrwxr-xr-x 2 root root 4096 Oct 13 00:53 .\ndrwxr-xr-x 9 root root 4096 Oct 13 00:53 ..\n-rw-r--r-- 1 root root 12288 Oct 13 00:53 records.sqlite3\n-rw-r--r-- 1 root root 5 Oct 13 00:53 upstream\n", "is_error": false, "read_only": false, "started_after_ms": 1646, "duration_ms": 24 }, { "id": "call_VS3aknslaHP218YKlFOroHTZ", "name": "Bash", "input": { "command": "cat /var/lib/rollout/upstream 2>&1", "description": "Read upstream file" }, "output": "8081\n", "is_error": false, "read_only": false, "started_after_ms": 1671, "duration_ms": 28 }, { "id": "call_bilS5RvSqebr10kUdNktJSOO", "name": "Bash", "input": { "command": "cat /etc/systemd/system/rollout-proxy.service /etc/systemd/system/rollout-v1.service /etc/systemd/system/rollout-v2.service /etc/systemd/system/rollout-seed.service 2>&1", "description": "Inspect all rollout service unit files" }, "output": "[Unit]\nAfter=rollout-seed.service rollout-v1.service\nDescription=Stable public rollout proxy\nRequires=rollout-seed.service rollout-v1.service\n\n[Service]\nEnvironment=\"LOCALE_ARCHIVE=/nix/store/c59mcax29xrwyfdqs308wkmn2srnmzkn-glibc-locales-2.42-67/lib/locale/locale-archive\"\nEnvironment=\"PATH=/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/bin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/bin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/bin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/bin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/bin:/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/sbin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/sbin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/sbin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/sbin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/sbin\"\nEnvironment=\"TZDIR=/nix/store/vlgjd2179ahfh509p1aid8fl22bw8ri3-tzdata-2026c/share/zoneinfo\"\nExecStart=/nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /nix/store/08ib8hkpsxizx3zrsv266idphl0r1hgb-rollout-proxy.py\nRestart=always\nRestartSec=1\n\n[Install]\nWantedBy=multi-user.target\n[Unit]\nAfter=rollout-seed.service\nDescription=Existing rollout v1 service\nRequires=rollout-seed.service\n\n[Service]\nEnvironment=\"LOCALE_ARCHIVE=/nix/store/c59mcax29xrwyfdqs308wkmn2srnmzkn-glibc-locales-2.42-67/lib/locale/locale-archive\"\nEnvironment=\"PATH=/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/bin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/bin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/bin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/bin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/bin:/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/sbin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/sbin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/sbin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/sbin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/sbin\"\nEnvironment=\"TZDIR=/nix/store/vlgjd2179ahfh509p1aid8fl22bw8ri3-tzdata-2026c/share/zoneinfo\"\nExecStart=/nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /nix/store/13qi755lbgrlrh6c5jqjdlpf1f7nvffv-rollout-v1.py\nRestart=always\nRestartSec=1\n\n[Install]\nWantedBy=multi-user.target\n[Unit]\nAfter=rollout-seed.service\nDescription=Agent-built rollout v2 slot\nRequires=rollout-seed.service\n\n[Service]\nEnvironment=\"LOCALE_ARCHIVE=/nix/store/c59mcax29xrwyfdqs308wkmn2srnmzkn-glibc-locales-2.42-67/lib/locale/locale-archive\"\nEnvironment=\"PATH=/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/bin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/bin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/bin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/bin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/bin:/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/sbin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/sbin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/sbin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/sbin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/sbin\"\nEnvironment=\"TZDIR=/nix/store/vlgjd2179ahfh509p1aid8fl22bw8ri3-tzdata-2026c/share/zoneinfo\"\nExecStart=/nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /opt/rollout/v2.py\nRestart=always\nRestartSec=1\n\n[Install]\nWantedBy=multi-user.target\n[Unit]\nBefore=rollout-v1.service rollout-v2.service rollout-proxy.service\nDescription=Seed live v1 state\n\n[Service]\nEnvironment=\"LOCALE_ARCHIVE=/nix/store/c59mcax29xrwyfdqs308wkmn2srnmzkn-glibc-locales-2.42-67/lib/locale/locale-archive\"\nEnvironment=\"PATH=/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/bin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/bin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/bin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/bin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/bin:/nix/store/97d5ygrvqj55f4nx1x34wfdcc7qn11c0-coreutils-9.11/sbin:/nix/store/ibg16grw5is7i7ilnflc5xmj6fwksqkl-findutils-4.11.0/sbin:/nix/store/4dgym2zhac9vy0vrih4gsplh0wpfl13m-gnugrep-3.12/sbin:/nix/store/rxd8p6g4k4s0sx4q1szmzvp9rsmhmfys-gnused-4.10/sbin:/nix/store/mc901k2s1n3v1disrj0356l7lwz7l6vg-systemd-261.1/sbin\"\nEnvironment=\"TZDIR=/nix/store/vlgjd2179ahfh509p1aid8fl22bw8ri3-tzdata-2026c/share/zoneinfo\"\nExecStart=/nix/store/44ql83wxi6z28pk20x4179khgs5i5anf-unit-script-rollout-seed-start/bin/rollout-seed-start \nRemainAfterExit=true\nType=oneshot\n\n[Install]\nWantedBy=multi-user.target\n", "is_error": false, "read_only": false, "started_after_ms": 3650, "duration_ms": 78 }, { "id": "call_S0prxSksR4l9vwPz3wrixxVT", "name": "Bash", "input": { "command": "systemctl status rollout-proxy.service rollout-v1.service rollout-v2.service 2>&1", "description": "Get current statuses" }, "output": "● rollout-proxy.service - Stable public rollout proxy\n Loaded: loaded (/etc/systemd/system/rollout-proxy.service; enabled; preset: ignored)\n Active: active (running) since Tue 2026-10-13 00:53:21 UTC; 14s ago\n Invocation: bb15f2fbe3ab4bfba06cbdd05946427b\n Main PID: 544 (python)\n IP: 226.2K in, 226.5K out\n IO: 0B read, 0B written\n Tasks: 1 (limit: 811)\n Memory: 17.7M (peak: 17.7M)\n CPU: 527ms\n CGroup: /system.slice/rollout-proxy.service\n └─544 /nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /nix/store/08ib8hkpsxizx3zrsv266idphl0r1hgb-rollout-proxy.py\n\nOct 13 00:53:21 rollout-one systemd[1]: Started Stable public rollout proxy.\n\n● rollout-v1.service - Existing rollout v1 service\n Loaded: loaded (/etc/systemd/system/rollout-v1.service; enabled; preset: ignored)\n Active: active (running) since Tue 2026-10-13 00:53:21 UTC; 14s ago\n Invocation: 8ecb3c705bc84e11819782f62a3f16bc\n Main PID: 543 (python)\n IP: 137.2K in, 132.1K out\n IO: 0B read, 0B written\n Tasks: 1 (limit: 811)\n Memory: 17.6M (peak: 17.7M)\n CPU: 509ms\n CGroup: /system.slice/rollout-v1.service\n └─543 /nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /nix/store/13qi755lbgrlrh6c5jqjdlpf1f7nvffv-rollout-v1.py\n\nOct 13 00:53:21 rollout-one systemd[1]: Started Existing rollout v1 service.\n\n× rollout-v2.service - Agent-built rollout v2 slot\n Loaded: loaded (/etc/systemd/system/rollout-v2.service; enabled; preset: ignored)\n Active: failed (Result: start-limit-hit) since Tue 2026-10-13 00:53:29 UTC; 6s ago\n Duration: 51ms\n Invocation: a756fe94dd054e9eadd12bc8168754cf\n Process: 617 ExecStart=/nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /opt/rollout/v2.py (code=exited, status=2)\n Main PID: 617 (code=exited, status=2)\n IP: 0B in, 0B out\n IO: 0B read, 0B written\n Mem peak: 4.3M\n CPU: 26ms\n\nOct 13 00:53:27 rollout-one systemd[1]: rollout-v2.service: Main process exited, code=exited, status=2/INVALIDARGUMENT\nOct 13 00:53:27 rollout-one systemd[1]: rollout-v2.service: Failed with result 'exit-code'.\nOct 13 00:53:29 rollout-one systemd[1]: rollout-v2.service: Scheduled restart job, restart counter is at 5.\nOct 13 00:53:29 rollout-one systemd[1]: rollout-v2.service: Start request repeated too quickly.\nOct 13 00:53:29 rollout-one systemd[1]: rollout-v2.service: Failed with result 'start-limit-hit'.\nOct 13 00:53:29 rollout-one systemd[1]: Failed to start Agent-built rollout v2 slot.\n\nExit code: exit status: 3", "is_error": true, "read_only": false, "started_after_ms": 3729, "duration_ms": 71 }, { "id": "call_cEsfQohtSZyQ3THagni3y8MT", "name": "Bash", "input": { "command": "ss -tlnp | grep -E '808[012]' 2>&1", "description": "Check listening ports" }, "output": "LISTEN 0 5 0.0.0.0:8080 0.0.0.0:* users:((\"python\",pid=544,fd=3))\nLISTEN 0 5 127.0.0.1:8081 0.0.0.0:* users:((\"python\",pid=543,fd=3))\n", "is_error": false, "read_only": false, "started_after_ms": 3800, "duration_ms": 65 }, { "id": "call_4ehFiLbdOOAv5WWhfspYVGhF", "name": "Bash", "input": { "command": "/nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python -c \"import sqlite3; conn=sqlite3.connect('/var/lib/rollout/records.sqlite3'); print(conn.execute(\\\"SELECT name FROM sqlite_master WHERE type='table'\\\").fetchall()); print(conn.execute('SELECT * FROM records LIMIT 10').fetchall() if any('records' in t for t in conn.execute(\\\"SELECT name FROM sqlite_master WHERE type='table'\\\").fetchall()) else 'no records table')\"", "description": "Inspect the seed SQLite database" }, "output": "[('records',)]\n[('customer-alpha-73c', 'alpha-original'), ('customer-beta-a19', 'beta-original')]\n", "is_error": false, "read_only": false, "started_after_ms": 7595, "duration_ms": 90 }, { "id": "call_BW2o1V5aq7sZQsc3iwhxaBnu", "name": "Bash", "input": { "command": "curl -sS http://127.0.0.1:8080/health; echo; curl -sS http://127.0.0.1:8080/version; echo; curl -sS http://127.0.0.1:8080/records/foo; echo; curl -sS -o /tmp/rec1 -w 'HTTP %{http_code}\\n' http://127.0.0.1:8080/records/foo; curl -sS -X PUT -d 'hello-bar' http://127.0.0.1:8080/records/foo -w 'HTTP %{http_code}\\n'; curl -sS http://127.0.0.1:8080/records/foo; echo", "description": "Probe live proxy behavior" }, "output": "ready\nv1\n\nHTTP 404\nHTTP 204\nhello-bar\n", "is_error": false, "read_only": false, "started_after_ms": 7686, "duration_ms": 215 }, { "id": "call_4QRSvxzKF60cZoyN8sk6rGgS", "name": "Bash", "input": { "command": "ls /var/lib/rollout/; which python python3; python3 --version; python3 -c 'import sqlite3,aiohttp,fastapi; print(\"ok\")' 2>&1; python3 -c 'import sqlite3, http.server; print(\"stdlib ok\")'", "description": "Inventory tools and runtime" }, "output": "records.sqlite3\nupstream\n/run/current-system/sw/bin/python\n/run/current-system/sw/bin/python3\nPython 3.14.7\nTraceback (most recent call last):\n File \"\", line 1, in \n import sqlite3,aiohttp,fastapi; print(\"ok\")\n ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\nModuleNotFoundError: No module named 'aiohttp'\nstdlib ok\n", "is_error": false, "read_only": false, "started_after_ms": 7901, "duration_ms": 438 }, { "id": "call_NVPDuZiI6LAA7lZE0taDgs7D", "name": "Bash", "input": { "command": "cat /nix/store/08ib8hkpsxizx3zrsv266idphl0r1hgb-rollout-proxy.py 2>&1 | head -100", "description": "Read proxy source" }, "output": "import http.client\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nUPSTREAM = \"/var/lib/rollout/upstream\"\n\nclass Handler(BaseHTTPRequestHandler):\n def forward(self):\n try:\n with open(UPSTREAM) as source:\n port = int(source.read().strip())\n body = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\")))\n connection = http.client.HTTPConnection(\"127.0.0.1\", port, timeout=2)\n connection.request(self.command, self.path, body=body)\n response = connection.getresponse()\n response_body = response.read()\n self.send_response(response.status)\n self.send_header(\"Content-Length\", str(len(response_body)))\n self.end_headers()\n self.wfile.write(response_body)\n connection.close()\n except Exception:\n self.send_response(502)\n self.send_header(\"Content-Length\", \"0\")\n self.end_headers()\n\n do_GET = forward\n do_PUT = forward\n\n def log_message(self, *_):\n pass\n\nThreadingHTTPServer((\"0.0.0.0\", 8080), Handler).serve_forever()\n", "is_error": false, "read_only": false, "started_after_ms": 12146, "duration_ms": 25 }, { "id": "call_dKCUjiw9yHO3V9u3wwhnW3DM", "name": "Bash", "input": { "command": "cat /nix/store/13qi755lbgrlrh6c5jqjdlpf1f7nvffv-rollout-v1.py 2>&1 | head -200", "description": "Read v1 source for reference" }, "output": "import sqlite3\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nDB = \"/var/lib/rollout/records.sqlite3\"\n\ndef database():\n connection = sqlite3.connect(DB, timeout=10)\n connection.execute(\"CREATE TABLE IF NOT EXISTS records (id TEXT PRIMARY KEY, value TEXT NOT NULL)\")\n return connection\n\nclass Handler(BaseHTTPRequestHandler):\n def send(self, status, body=b\"\"):\n self.send_response(status)\n self.send_header(\"Content-Length\", str(len(body)))\n self.end_headers()\n self.wfile.write(body)\n\n def do_GET(self):\n if self.path == \"/health\":\n self.send(200, b\"ready\")\n return\n if self.path == \"/version\":\n self.send(200, b\"v1\")\n return\n if self.path.startswith(\"/records/\"):\n connection = database()\n row = connection.execute(\"SELECT value FROM records WHERE id=?\", (self.path[9:],)).fetchone()\n connection.close()\n if row is None:\n self.send(404)\n else:\n self.send(200, row[0].encode())\n return\n self.send(404)\n\n def do_PUT(self):\n if not self.path.startswith(\"/records/\"):\n self.send(404)\n return\n value = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\"))).decode()\n connection = database()\n connection.execute(\n \"INSERT INTO records(id,value) VALUES(?,?) ON CONFLICT(id) DO UPDATE SET value=excluded.value\",\n (self.path[9:], value),\n )\n connection.commit()\n connection.close()\n self.send(204)\n\n def log_message(self, *_):\n pass\n\nThreadingHTTPServer((\"127.0.0.1\", 8081), Handler).serve_forever()\n", "is_error": false, "read_only": false, "started_after_ms": 12172, "duration_ms": 25 }, { "id": "call_V3MzyS4YY8Mj13C86NG9BtKh", "name": "TodoWrite", "input": { "todos": [ { "activeForm": "Writing /opt/rollout/v2.py", "content": "Write /opt/rollout/v2.py on 127.0.0.1:8082 sharing the existing SQLite", "status": "in_progress" }, { "activeForm": "Starting rollout-v2.service and probing it", "content": "Start rollout-v2.service and probe all four endpoints on 8082", "status": "pending" }, { "activeForm": "Updating proxy unit ordering", "content": "Add v2 ordering to the proxy unit and daemon-reload", "status": "pending" }, { "activeForm": "Flipping upstream to 8082 atomically", "content": "Atomically flip /var/lib/rollout/upstream to 8082", "status": "pending" }, { "activeForm": "Verifying cutover through public 8080", "content": "Verify cutover through public 8080 (health/version/records/PUT round-trip)", "status": "pending" }, { "activeForm": "Confirming durability and service states", "content": "Confirm durability (restart resilience, enabled at boot, services never stopped)", "status": "pending" } ] }, "output": "Added:\n + Write /opt/rollout/v2.py on 127.0.0.1:8082 sharing the existing SQLite\n + Start rollout-v2.service and probe all four endpoints on 8082\n + Add v2 ordering to the proxy unit and daemon-reload\n + Atomically flip /var/lib/rollout/upstream to 8082\n + Verify cutover through public 8080 (health/version/records/PUT round-trip)\n + Confirm durability (restart resilience, enabled at boot, services never stopped)\n\nCurrent tasks:\n ◉ Write /opt/rollout/v2.py on 127.0.0.1:8082 sharing the existing SQLite\n ○ Start rollout-v2.service and probe all four endpoints on 8082\n ○ Add v2 ordering to the proxy unit and daemon-reload\n ○ Atomically flip /var/lib/rollout/upstream to 8082\n ○ Verify cutover through public 8080 (health/version/records/PUT round-trip)\n ○ Confirm durability (restart resilience, enabled at boot, services never stopped)\n", "is_error": false, "read_only": true, "started_after_ms": 53812, "duration_ms": 0 }, { "id": "call_g4AcPoDM5PQNGMxs9XzP4ymc", "name": "Write", "input": { "content": "import sqlite3\nfrom http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n\nDB = \"/var/lib/rollout/records.sqlite3\"\n\n\ndef database():\n connection = sqlite3.connect(DB, timeout=10)\n connection.execute(\n \"CREATE TABLE IF NOT EXISTS records (id TEXT PRIMARY KEY, value TEXT NOT NULL)\"\n )\n return connection\n\n\nclass Handler(BaseHTTPRequestHandler):\n def send(self, status, body=b\"\"):\n self.send_response(status)\n self.send_header(\"Content-Length\", str(len(body)))\n self.end_headers()\n self.wfile.write(body)\n\n def do_GET(self):\n if self.path == \"/health\":\n self.send(200, b\"ready\")\n return\n if self.path == \"/version\":\n self.send(200, b\"v2\")\n return\n if self.path.startswith(\"/records/\"):\n record_id = self.path[len(\"/records/\"):]\n connection = database()\n row = connection.execute(\n \"SELECT value FROM records WHERE id=?\", (record_id,)\n ).fetchone()\n connection.close()\n if row is None:\n self.send(404)\n else:\n self.send(200, row[0].encode(\"utf-8\"))\n return\n self.send(404)\n\n def do_PUT(self):\n if not self.path.startswith(\"/records/\"):\n self.send(404)\n return\n record_id = self.path[len(\"/records/\"):]\n body = self.rfile.read(int(self.headers.get(\"Content-Length\", \"0\"))).decode(\"utf-8\")\n connection = database()\n connection.execute(\n \"INSERT INTO records(id,value) VALUES(?,?) \"\n \"ON CONFLICT(id) DO UPDATE SET value=excluded.value\",\n (record_id, body),\n )\n connection.commit()\n connection.close()\n self.send(204)\n\n def log_message(self, *_):\n pass\n\n\nThreadingHTTPServer((\"127.0.0.1\", 8082), Handler).serve_forever()\n", "file_path": "/opt/rollout/v2.py" }, "output": "Successfully wrote to /opt/rollout/v2.py", "is_error": false, "read_only": false, "started_after_ms": 56839, "duration_ms": 0 }, { "id": "call_657DnODoJ6p1HaurOdfnyWN2", "name": "Bash", "input": { "command": "chmod 0755 /opt/rollout && systemctl reset-failed rollout-v2.service && systemctl start rollout-v2.service && sleep 0.4 && systemctl --no-pager status rollout-v2.service | sed -n '1,12p'", "description": "Start rollout-v2.service and check status" }, "output": "● rollout-v2.service - Agent-built rollout v2 slot\n Loaded: loaded (/etc/systemd/system/rollout-v2.service; enabled; preset: ignored)\n Active: active (running) since Tue 2026-10-13 00:54:31 UTC; 449ms ago\n Invocation: d6d294e7f4f04f37b49efd5936a568d1\n Main PID: 5938 (python)\n IP: 0B in, 0B out\n IO: 0B read, 0B written\n Tasks: 1 (limit: 811)\n Memory: 9.6M (peak: 9.8M)\n CPU: 88ms\n CGroup: /system.slice/rollout-v2.service\n └─5938 /nix/store/3n4qphl9s728sz8frmpqqrv9b1m87g68-python3-3.14.7/bin/python /opt/rollout/v2.py\n", "is_error": false, "read_only": false, "started_after_ms": 58491, "duration_ms": 610 }, { "id": "call_gpT8abQWAQ2IbBe1uSbGizWZ", "name": "Bash", "input": { "command": "ss -tlnp | grep -E '808[0122]'; echo ---; for path in /health /version /records/customer-alpha-73c /records/customer-beta-a19 /records/missing; do printf 'GET %s -> ' \"$path\"; curl -sS -o /tmp/v2.body -w '%{http_code} ' \"http://127.0.0.1:8082$path\"; cat /tmp/v2.body; echo; done; echo ---; printf 'PUT round-trip -> '; curl -sS -X PUT --data-binary 'v2-direct-test' -o /dev/null -w '%{http_code}\\n' \"http://127.0.0.1:8082/records/_v2direct\"; printf 'GET _v2direct -> '; curl -sS -o /tmp/v2.body -w '%{http_code} ' \"http://127.0.0.1:8082/records/_v2direct\"; cat /tmp/v2.body; echo", "description": "Probe v2 directly: listening sockets, GETs, PUT round-trip" }, "output": "LISTEN 0 5 0.0.0.0:8080 0.0.0.0:* users:((\"python\",pid=544,fd=3))\nLISTEN 0 5 127.0.0.1:8082 0.0.0.0:* users:((\"python\",pid=5938,fd=3))\nLISTEN 0 5 127.0.0.1:8081 0.0.0.0:* users:((\"python\",pid=543,fd=3))\n---\nGET /health -> 200 ready\nGET /version -> 200 v2\nGET /records/customer-alpha-73c -> 200 alpha-original\nGET /records/customer-beta-a19 -> 200 beta-original\nGET /records/missing -> 404 \n---\nPUT round-trip -> 204\nGET _v2direct -> 200 v2-direct-test\n", "is_error": false, "read_only": false, "started_after_ms": 61358, "duration_ms": 218 }, { "id": "call_22LyoM4hK5vCMTHQszKXm9H7", "name": "Edit", "input": { "file_path": "/etc/systemd/system/rollout-proxy.service", "new_string": "[Unit]\nAfter=rollout-seed.service rollout-v1.service rollout-v2.service\nDescription=Stable public rollout proxy\nRequires=rollout-seed.service rollout-v1.service\nWants=rollout-v2.service", "old_string": "[Unit]\nAfter=rollout-seed.service rollout-v1.service\nDescription=Stable public rollout proxy\nRequires=rollout-seed.service rollout-v1.service" }, "output": "Tool Edit failed: Read-only file system (os error 30)", "is_error": true, "read_only": false, "started_after_ms": 63650, "duration_ms": 1 }, { "id": "call_b7p5a2BDcWcdkgzFvSwoRW8I", "name": "Bash", "input": { "command": "touch /etc/systemd/system/rollout-proxy.service.d/x.test 2>&1; touch /run/systemd/system/rollout-proxy.service.d/x.test 2>&1; touch /etc/systemd/system/.test 2>&1; touch /run/systemd/.test 2>&1; ls -ld /run/systemd /run/systemd/system 2>&1", "description": "Probe writable filesystem locations for systemd drop-ins" }, "output": "touch: cannot touch '/etc/systemd/system/rollout-proxy.service.d/x.test': No such file or directory\ntouch: cannot touch '/run/systemd/system/rollout-proxy.service.d/x.test': No such file or directory\ntouch: cannot touch '/etc/systemd/system/.test': Read-only file system\ndrwxr-xr-x 25 root root 860 Oct 13 00:54 /run/systemd\ndrwxr-xr-x 2 root root 40 Oct 13 00:53 /run/systemd/system\n", "is_error": false, "read_only": false, "started_after_ms": 66542, "duration_ms": 87 }, { "id": "call_q6QdP5MV0rHesvXY8uwQRKnc", "name": "Bash", "input": { "command": "ls -la /run/systemd/system/ 2>&1; echo ---; touch /run/systemd/system/.test 2>&1 && rm /run/systemd/system/.test 2>&1; echo ---; mkdir -p /run/systemd/system/rollout-proxy.service.d 2>&1 && ls -ld /run/systemd/system/rollout-proxy.service.d", "description": "Inspect /run/systemd/system and try creating drop-in" }, "output": "total 0\ndrwxr-xr-x 2 root root 40 Oct 13 00:53 .\ndrwxr-xr-x 25 root root 860 Oct 13 00:54 ..\n---\n---\ndrwxr-xr-x 2 root root 40 Oct 13 00:54 /run/systemd/system/rollout-proxy.service.d\n", "is_error": false, "read_only": false, "started_after_ms": 68432, "duration_ms": 63 }, { "id": "call_kH4SWoHV3NJAKWU4ulowD0Sn", "name": "Write", "input": { "content": "[Unit]\nAfter=rollout-v2.service\nWants=rollout-v2.service\n", "file_path": "/run/systemd/system/rollout-proxy.service.d/10-after-v2.conf" }, "output": "Successfully wrote to /run/systemd/system/rollout-proxy.service.d/10-after-v2.conf", "is_error": false, "read_only": false, "started_after_ms": 70195, "duration_ms": 0 }, { "id": "call_o2MVAB1xNhKngnpa8JHqYDSZ", "name": "Bash", "input": { "command": "systemctl daemon-reload && echo '--- effective proxy unit (Unit section) ---' && systemctl cat rollout-proxy.service | sed -n '/^\\[Unit\\]/,/^\\[/p' | head -n 30", "description": "Reload systemd and inspect effective proxy unit" }, "output": "--- effective proxy unit (Unit section) ---\n[Unit]\nAfter=rollout-seed.service rollout-v1.service\nDescription=Stable public rollout proxy\nRequires=rollout-seed.service rollout-v1.service\n\n[Service]\n[Unit]\nAfter=rollout-v2.service\nWants=rollout-v2.service\n", "is_error": false, "read_only": false, "started_after_ms": 71787, "duration_ms": 714 }, { "id": "call_DlKa1IDZOgO1s7biPnt1TcZ4", "name": "Bash", "input": { "command": "systemctl --no-pager is-active rollout-proxy.service rollout-v1.service rollout-v2.service; echo ---; cat /var/lib/rollout/upstream; echo ---; curl -sS -o /tmp/p.body -w 'public /version -> %{http_code} ' \"http://127.0.0.1:8080/version\"; cat /tmp/p.body; echo; curl -sS -o /tmp/p.body -w 'public /records/customer-alpha-73c -> %{http_code} ' \"http://127.0.0.1:8080/records/customer-alpha-73c\"; cat /tmp/p.body; echo", "description": "Verify service states, current upstream content, and proxy still serves v1" }, "output": "active\nactive\nactive\n---\n8081\n---\npublic /version -> 200 v1\npublic /records/customer-alpha-73c -> 200 alpha-original\n", "is_error": false, "read_only": false, "started_after_ms": 74973, "duration_ms": 82 }, { "id": "call_cBuoXCgSiTHnhN3dQpVTN06Z", "name": "Bash", "input": { "command": "python3 -c '\nimport os, tempfile\ntarget = \"/var/lib/rollout/upstream\"\nfd, tmp = tempfile.mkstemp(dir=\"/var/lib/rollout\", prefix=\".upstream.\")\ntry:\n os.write(fd, b\"8082\")\n os.fsync(fd)\nfinally:\n os.close(fd)\nos.replace(tmp, target)\nprint(\"flipped\")\n' && echo --- && cat /var/lib/rollout/upstream && echo --- && ls -la /var/lib/rollout/", "description": "Atomically swap upstream to 8082 and verify" }, "output": "flipped\n---\n8082---\ntotal 24\ndrwxr-xr-x 2 root root 4096 Oct 13 00:54 .\ndrwxr-xr-x 9 root root 4096 Oct 13 00:53 ..\n-rw-r--r-- 1 root root 12288 Oct 13 00:54 records.sqlite3\n-rw------- 1 root root 4 Oct 13 00:54 upstream\n", "is_error": false, "read_only": false, "started_after_ms": 77394, "duration_ms": 152 }, { "id": "call_OLGUnBJVbSwAhkWmgDxvlim1", "name": "Bash", "input": { "command": "echo '--- read repeated to flush any leftover v1 frame ---'; for path in /health /version /records/customer-alpha-73c /records/customer-beta-a19 /records/missing; do printf 'public GET %-40s -> ' \"$path\"; curl -sS -o /tmp/p.body -w '%{http_code} body=' \"http://127.0.0.1:8080$path\"; cat /tmp/p.body; echo; done; echo ---; printf 'public PUT round-trip -> '; curl -sS -X PUT --data-binary 'alpha-original' -o /dev/null -w '%{http_code} body=PUT ok\\n' \"http://127.0.0.1:8080/records/customer-alpha-73c\"; printf 'public GET that record back -> '; curl -sS -o /tmp/p.body -w '%{http_code} body=' \"http://127.0.0.1:8080/records/customer-alpha-73c\"; cat /tmp/p.body; echo; printf 'public GET other record -> '; curl -sS -o /tmp/p.body -w '%{http_code} body=' \"http://127.0.0.1:8080/records/customer-beta-a19\"; cat /tmp/p.body; echo; echo '--- stress: 200 requests alternating health/version/records ---'; fail=0; for i in $(seq 1 200); do case $((i % 3)) in 0) curl -sS -o /dev/null -w '' -f \"http://127.0.0.1:8080/health\" || fail=$((fail+1));; 1) curl -sS -o /dev/null -w '' -f \"http://127.0.0.1:8080/version\" || fail=$((fail+1));; 2) curl -sS -o /dev/null -w '' -f \"http://127.0.0.1:8080/records/customer-alpha-73c\" || fail=$((fail+1));; esac; done; echo \"failed count: $fail\"", "description": "Validate cutover through public 8080 and stress-test" }, "output": "--- read repeated to flush any leftover v1 frame ---\npublic GET /health -> 200 body=ready\npublic GET /version -> 200 body=v2\npublic GET /records/customer-alpha-73c -> 200 body=alpha-original\npublic GET /records/customer-beta-a19 -> 200 body=beta-original\npublic GET /records/missing -> 404 body=\n---\npublic PUT round-trip -> 204 body=PUT ok\npublic GET that record back -> 200 body=alpha-original\npublic GET other record -> 200 body=beta-original\n--- stress: 200 requests alternating health/version/records ---\nfailed count: 2\n\ncurl: (22) The requested URL returned error: 502\ncurl: (22) The requested URL returned error: 502\n", "is_error": false, "read_only": false, "started_after_ms": 80661, "duration_ms": 44743 } ], "timing": { "total_duration_ms": 128480, "model_rounds": [ { "index": 1, "started_after_ms": 1, "duration_ms": 1597, "status": "completed", "usage": { "input_tokens": 478, "output_tokens": 162, "cache_read_tokens": 3037, "cache_creation_tokens": 0, "cost_usd": 0.00052002 } }, { "index": 2, "started_after_ms": 1840, "duration_ms": 1805, "status": "completed", "usage": { "input_tokens": 404, "output_tokens": 233, "cache_read_tokens": 3514, "cache_creation_tokens": 0, "cost_usd": 0.00061164 } }, { "index": 3, "started_after_ms": 3871, "duration_ms": 3723, "status": "completed", "usage": { "input_tokens": 3471, "output_tokens": 602, "cache_read_tokens": 3917, "cache_creation_tokens": 0, "cost_usd": 0.00199872 } }, { "index": 4, "started_after_ms": 8342, "duration_ms": 3803, "status": "completed", "usage": { "input_tokens": 762, "output_tokens": 562, "cache_read_tokens": 7387, "cache_creation_tokens": 0, "cost_usd": 0.00134622 } }, { "index": 5, "started_after_ms": 12202, "duration_ms": 41607, "status": "completed", "usage": { "input_tokens": 1216, "output_tokens": 7152, "cache_read_tokens": 8148, "cache_creation_tokens": 0, "cost_usd": 0.00943608 } }, { "index": 6, "started_after_ms": 53843, "duration_ms": 2995, "status": "completed", "usage": { "input_tokens": 7402, "output_tokens": 470, "cache_read_tokens": 9363, "cache_creation_tokens": 0, "cost_usd": 0.00334638 } }, { "index": 7, "started_after_ms": 56842, "duration_ms": 1647, "status": "completed", "usage": { "input_tokens": 497, "output_tokens": 96, "cache_read_tokens": 16764, "cache_creation_tokens": 0, "cost_usd": 0.00127014 } }, { "index": 8, "started_after_ms": 59105, "duration_ms": 2252, "status": "completed", "usage": { "input_tokens": 337, "output_tokens": 286, "cache_read_tokens": 17260, "cache_creation_tokens": 0, "cost_usd": 0.0014799 } }, { "index": 9, "started_after_ms": 61579, "duration_ms": 2070, "status": "completed", "usage": { "input_tokens": 511, "output_tokens": 223, "cache_read_tokens": 17596, "cache_creation_tokens": 0, "cost_usd": 0.00147666 } }, { "index": 10, "started_after_ms": 63652, "duration_ms": 2888, "status": "completed", "usage": { "input_tokens": 252, "output_tokens": 270, "cache_read_tokens": 18106, "cache_creation_tokens": 0, "cost_usd": 0.00148596 } }, { "index": 11, "started_after_ms": 66631, "duration_ms": 1800, "status": "completed", "usage": { "input_tokens": 400, "output_tokens": 148, "cache_read_tokens": 18357, "cache_creation_tokens": 0, "cost_usd": 0.00139902 } }, { "index": 12, "started_after_ms": 68496, "duration_ms": 1698, "status": "completed", "usage": { "input_tokens": 240, "output_tokens": 134, "cache_read_tokens": 18756, "cache_creation_tokens": 0, "cost_usd": 0.00135816 } }, { "index": 13, "started_after_ms": 70198, "duration_ms": 1586, "status": "completed", "usage": { "input_tokens": 170, "output_tokens": 87, "cache_read_tokens": 18995, "cache_creation_tokens": 0, "cost_usd": 0.0012951 } }, { "index": 14, "started_after_ms": 72502, "duration_ms": 2470, "status": "completed", "usage": { "input_tokens": 167, "output_tokens": 275, "cache_read_tokens": 19164, "cache_creation_tokens": 0, "cost_usd": 0.00152994 } }, { "index": 15, "started_after_ms": 75057, "duration_ms": 2336, "status": "completed", "usage": { "input_tokens": 327, "output_tokens": 256, "cache_read_tokens": 19330, "cache_creation_tokens": 0, "cost_usd": 0.0015651 } }, { "index": 16, "started_after_ms": 77547, "duration_ms": 3112, "status": "completed", "usage": { "input_tokens": 369, "output_tokens": 541, "cache_read_tokens": 19656, "cache_creation_tokens": 0, "cost_usd": 0.00193926 } }, { "index": 17, "started_after_ms": 125406, "duration_ms": 3073, "status": "completed", "usage": { "input_tokens": 729, "output_tokens": 335, "cache_read_tokens": 20024, "cache_creation_tokens": 0, "cost_usd": 0.00182214 } } ] } }