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BETAGuardrails are in beta. The library, the configuration format and the CLI command can still change.

Guardrails / github

Repository declares its code owners

github/codeowners-present@v1

The repository carries a CODEOWNERS file where GitHub looks for one, naming at least one rule, so every change has somebody to review it.

Idgithub/codeowners-present
Versionv1
Categorygithub
Default severitywarning
Interpreterpython3
Timeout30 seconds
Violations tolerated0
Collectsgithub

Collectors

This guardrail gathers nothing itself. It depends on the collectors below, which the CLI runs once per build before any check, and reads what they found out of GUARDRAIL_FACTS. A collector that collects nothing skips this guardrail rather than failing it.

CollectorGathersInputs it is given
githubWhat GitHub itself reads out of the repository: the Actions workflows in .github/workflows, read as they are written, and the CODEOWNERS file, read as rules. For a workflow, which events start it, what token permissions it hands a job, which runner each job asks for, and every action a step reaches for and how tightly it is pinned. For CODEOWNERS, every pattern in file order with the owners it names, and the owners that apply to the paths a guardrail asks about, resolved the way GitHub resolves them, where the last rule to match a path is the one that owns it. Names and shapes only, never a secret, an input value or an environment value.workflows

The inputs above are this guardrail's own, passed straight through. Configuring one in buildnote.json changes what is collected, and two guardrails configured the same way share the one collection.

Configuration

json
{
  "guardrails": {
      "failOn": "error",
      "comment": true,
      "checks": [
          {
              "use": "github/codeowners-present@v1",
              "severity": "warning",
              "with": {
                  "workflows": ".github/workflows/*.yml,.github/workflows/*.yaml"
              },
              "exemptions": []
          }
      ]
  }
}

Inputs

InputDescriptionDefaultEnvironment variable
workflowsComma separated globs naming the workflows to read..github/workflows/*.yml,.github/workflows/*.yamlGUARDRAIL_INPUT_WORKFLOWS

How to fix

Add a CODEOWNERS at the repository root, under .github/ or under docs/, which are the three places GitHub looks, in that order:

*               @acme/platform
/terraform/     @acme/infrastructure
/docs/          @acme/docs

Without one a pull request has no reviewer GitHub can request, so review lands on whoever notices. An auditor asking who approved a change to production has the same problem.

More in github

  • github/actions-pinned-by-digest. Every third party action a workflow uses is pinned to a full commit sha rather than to a tag or a branch.
  • github/codeowners-catch-all. CODEOWNERS declares a rule matching every path, so a file nobody thought about still has an owner.
  • github/codeowners-no-unowned-rules. No rule in CODEOWNERS names an empty set of owners, which would take ownership away from everything it matches.
  • github/codeowners-owners-per-rule. Every rule in CODEOWNERS names at least the minimum owners and no more than the maximum, so review is neither one person's bus factor nor everybody's problem.
  • github/codeowners-parses. Every line of CODEOWNERS that is not a comment reads as a rule to GitHub, so no ownership is silently lost to a line GitHub ignores.
  • github/codeowners-team-owned. Every rule in CODEOWNERS names at least one GitHub team, so ownership survives the people currently in it.
  • github/job-timeout-set. Every job declares how long it may run, so a hung job is cut off rather than holding a runner until GitHub's own limit.
  • github/least-privilege-token. Every workflow declares permissions, and none of them takes write access to everything.

All 11 github guardrails

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