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| 1 | +# gha-log-uploader |
| 2 | + |
| 3 | +Downloads a completed GitHub Actions job log and archives it to |
| 4 | +`s3://ossci-raw-job-status/log/`. This is the log-download half of the old |
| 5 | +`github-status-test` lambda, moved behind the PyTorch bot so onboarding a repo to |
| 6 | +HUD no longer needs an admin to add a repo webhook. See |
| 7 | +https://github.com/pytorch/test-infra/issues/7549. |
| 8 | + |
| 9 | +`github-status-test` still exists and is untouched. It is deleted after the |
| 10 | +cutover, not edited into this shape. |
| 11 | + |
| 12 | +## How it is invoked |
| 13 | + |
| 14 | +Only through `lambda:InvokeFunction`. **There is no API Gateway integration and no |
| 15 | +function URL, and neither should be added** — the function must not be reachable |
| 16 | +from the internet. |
| 17 | + |
| 18 | +Two callers, both in torchci, both using `InvocationType: "Event"`: |
| 19 | + |
| 20 | +- `lib/bot/logUploader.ts`, on a `workflow_job` webhook with `action == completed`. |
| 21 | +- `lib/jobUtils.ts`'s `backfillMissingLog`, when Dr.CI notices a log is missing. |
| 22 | + External callers reach the same path through the authenticated |
| 23 | + `POST /api/log-uploader/backfill` route. |
| 24 | + |
| 25 | +Payload: |
| 26 | + |
| 27 | +```json |
| 28 | +{ "repo": "pytorch/executorch", "job_id": 12345, "conclusion": "failure" } |
| 29 | +``` |
| 30 | + |
| 31 | +`conclusion` is optional. A malformed payload raises, which means Lambda retries |
| 32 | +twice and then DLQs it. |
| 33 | + |
| 34 | +## What fails how |
| 35 | + |
| 36 | +Callers invoke asynchronously, so *raising* is what reaches Lambda's retries and |
| 37 | +then the dead-letter queue; *returning* records the invocation as a success no |
| 38 | +matter what the return value says. Which failures do which: |
| 39 | + |
| 40 | +| Failure | Behaviour | |
| 41 | +| --- | --- | |
| 42 | +| Network error reaching GitHub | raises — retried, then DLQ | |
| 43 | +| GitHub 5xx or 429 | raises — retried, then DLQ | |
| 44 | +| No usable credential | raises — retried, then DLQ | |
| 45 | +| Malformed payload | raises — retried, then DLQ | |
| 46 | +| GitHub 404 (log has aged out), 401, 403 | returns `stored: false`, no retry | |
| 47 | +| Classifier call fails or times out | returns `classified: false`, no retry | |
| 48 | + |
| 49 | +The bottom two are deliberate. A log GitHub has already dropped does not come |
| 50 | +back on the third attempt, and re-running a whole download to retry a classifier |
| 51 | +handoff would re-fetch megabytes to redo something that takes milliseconds. |
| 52 | +`stored: false` is therefore not visible on the DLQ; if you want to alarm on it, |
| 53 | +match the terminal `ERROR <status> downloading log` line specifically. Do **not** |
| 54 | +alarm on `ERROR` generally: `installation_token` logs one every time it falls |
| 55 | +back to the PAT pool, which is a path that then usually succeeds. |
| 56 | + |
| 57 | +## Classification |
| 58 | + |
| 59 | +After a log is stored, `log_classifier` is called through its function URL — |
| 60 | +byte for byte the call `github-status-test` makes today. |
| 61 | + |
| 62 | +Function URLs only support the `RequestResponse` invocation type, so there is no |
| 63 | +way to ask for fire-and-forget. `CLASSIFIER_TIMEOUT` gets close enough: after 30s |
| 64 | +this stops waiting for the reply. Disconnecting does not cancel the classifier — |
| 65 | +it runs to completion regardless — so nothing is lost by hanging up, and |
| 66 | +`github-status-test`'s 274s/344s/400s/900s duration maxima do not carry over. |
| 67 | + |
| 68 | +That bound is load-bearing, not tidiness. `urlopen` with no `timeout` has none at |
| 69 | +all, so a connection that is accepted and never answered raises nothing and burns |
| 70 | +the entire function timeout. Since callers invoke asynchronously, Lambda counts |
| 71 | +that as a failure and replays the whole invocation twice more, re-downloading the |
| 72 | +same log each time and eventually DLQ-ing a job whose log was archived fine on |
| 73 | +the first attempt. `github-status-test` does hit its 900s ceiling, so this is an |
| 74 | +observed tail, not a theoretical one. |
| 75 | + |
| 76 | +With the wait bounded, every step has an explicit ceiling — two 30s log fetches |
| 77 | +at most, then a 30s classifier call — so a **300s function timeout** is |
| 78 | +comfortable, rather than the 900s `github-status-test` needs. |
| 79 | + |
| 80 | +The way out is `lambda:InvokeFunction` with `InvocationType: "Event"`, which |
| 81 | +needs `log_classifier` to accept a plain `{"job_id", "repo"}` payload — it |
| 82 | +currently only parses the API Gateway request its `lambda_http` handler expects. |
| 83 | +That change also lets its `AuthType: NONE` function URL be retired, once |
| 84 | +`backfillJobs.mjs`, `keep-going-call-log-classifier` and `github-status-test` |
| 85 | +move off it. Worth doing on its own, not as a rider on this migration. |
| 86 | + |
| 87 | +A failed handoff is logged and reported as `classified: false`, not raised. |
| 88 | +Raising would make Lambda retry the whole function, re-downloading a |
| 89 | +multi-megabyte log from GitHub to retry something that takes milliseconds; the |
| 90 | +log itself is already safe in S3. |
| 91 | + |
| 92 | +## What it does not do |
| 93 | + |
| 94 | +It does not archive raw webhook payloads. Nothing read them — |
| 95 | +`clickhouse-replicator-s3` has no `SUPPORTED_PATHS` entry for `workflow_job/`, |
| 96 | +`workflow_run/`, or `full_workflow_*/`, and ClickHouse gets jobs from DynamoDB via |
| 97 | +`clickhouse-replicator-dynamo`. |
| 98 | + |
| 99 | +## S3 key scheme |
| 100 | + |
| 101 | +`log/<job_id>` for `pytorch/pytorch`, `log/<owner>/<repo>/<job_id>` for everything |
| 102 | +else. The asymmetry is historical but load-bearing: the `log_url` ALIAS in |
| 103 | +`clickhouse_db_schema/default.workflow_job/schema.sql` derives URLs from exactly |
| 104 | +this shape, so changing it silently breaks every log link in the HUD. |
| 105 | + |
| 106 | +## GitHub credentials |
| 107 | + |
| 108 | +Job logs are downloaded with a GitHub App installation token, falling back to the |
| 109 | +`GITHUB_TOKENS` PAT pool when the app is rate limited, rejected, or not installed |
| 110 | +on the repo. |
| 111 | + |
| 112 | +| Env var | Required | Purpose | |
| 113 | +| --- | --- | --- | |
| 114 | +| `GITHUB_APP_ID` | no | Numeric app id used to mint installation tokens, e.g. `4550824` — the id of the `pytorch-bot-preview` app. Must be the number: it goes through `int()`, so an app slug fails | |
| 115 | +| `GITHUB_APP_PRIVATE_KEY` | no | The app's private key, base64-encoded PEM (same encoding torchci uses) | |
| 116 | +| `GITHUB_TOKENS` | yes | Comma-separated PAT pool, used as the fallback and when no app is configured | |
| 117 | + |
| 118 | +With both app vars unset the function only uses `GITHUB_TOKENS`, so the app can be |
| 119 | +rolled back by clearing the env vars — no code change or redeploy needed. |
| 120 | + |
| 121 | +Notes on the app path: |
| 122 | + |
| 123 | +- Installation tokens last an hour and are cached per repo in module scope, so a |
| 124 | + warm invocation reuses one rather than minting a token per job. |
| 125 | +- The app's rate limit is per installation. `pytorch` is enterprise-owned, so its |
| 126 | + installation gets 15,000 requests/hour, independent of any other app's quota. |
| 127 | + Use a dedicated app rather than the shared `pytorch-bot` installation, whose |
| 128 | + quota Dr. CI and the HUD already draw on. |
| 129 | +- Repos outside the installation (e.g. `vllm-project/vllm`) resolve to no |
| 130 | + installation and go straight to the PAT pool; that negative result is cached |
| 131 | + briefly to avoid a lookup per job. |
| 132 | +- Downloading job logs is documented as needing `actions: read`. It currently |
| 133 | + works without it because pytorch repos are public, but the permission should be |
| 134 | + granted before any private repo is onboarded. |
| 135 | + |
| 136 | +## One-time AWS setup |
| 137 | + |
| 138 | +Not done by CI. Needed before the deploy workflow can run. |
| 139 | + |
| 140 | +1. Create the function: python3.12, x86_64, handler `lambda_function.lambda_handler`, |
| 141 | + 512 MB, **300s timeout** — every step is individually bounded, so this does |
| 142 | + not need `github-status-test`'s 900s. See Classification above. |
| 143 | +2. Give its execution role `s3:PutObject` on `arn:aws:s3:::ossci-raw-job-status/log/*` |
| 144 | + plus the usual CloudWatch Logs permissions. No `lambda:InvokeFunction` is |
| 145 | + needed while the classifier is reached over its function URL. |
| 146 | +3. Set the env vars above. Prefer fresh credentials over copying |
| 147 | + `github-status-test`'s, whose PATs sit in plaintext env vars and are due for |
| 148 | + rotation. |
| 149 | +4. Configure an on-failure destination or DLQ, and alarm on it. For a trunk-only |
| 150 | + job that is the only signal its log went missing — Dr.CI's self-heal only |
| 151 | + covers PR jobs. See "What fails how" for what does and does not land there. |
| 152 | +5. Add the invoke grant for torchci, and nothing else: |
| 153 | + ``` |
| 154 | + aws lambda add-permission --function-name gha-log-uploader \ |
| 155 | + --statement-id torchci-invoke --action lambda:InvokeFunction \ |
| 156 | + --principal arn:aws:iam::308535385114:user/pytorch_hud_bot |
| 157 | + ``` |
| 158 | + Confirm that user really is the principal behind torchci's |
| 159 | + `OUR_AWS_ACCESS_KEY_ID` before granting. |
| 160 | +6. Create the `gha_workflow_gha-log-uploader-lambda` IAM role the deploy workflow |
| 161 | + assumes, mirroring `gha_workflow_github-status-test-lambda`. |
| 162 | +7. Nothing to wire for classification: the classifier is called over its existing |
| 163 | + function URL, so there is no notification or extra permission to add. |
| 164 | + |
| 165 | +## Deployment |
| 166 | + |
| 167 | +`make deploy` publishes to `$LATEST` and is live immediately; the deploy job in |
| 168 | +`.github/workflows/gha-log-uploader-lambda.yml` runs it on every push to main that |
| 169 | +touches this directory. `make prepare` verifies the zip contains every vendored |
| 170 | +module and `make deploy` refuses to publish a package built for a different python |
| 171 | +than the function runs, but there is no staged rollout behind either. |
| 172 | + |
| 173 | +`PYTHON_VERSION` in the Makefile must match the function's runtime. Changing one |
| 174 | +without the other breaks every invocation. |
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