Guardrails / ownership

Each CODEOWNERS rule names a workable number of owners

ownership/owners-per-rule@v1

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.

Id	ownership/owners-per-rule
Version	v1
Category	ownership
Default severity	warning
Interpreter	python3
Timeout	30 seconds
Violations tolerated	0
Collects	codeowners

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.

Collector	Gathers	Inputs it is given
codeowners	The CODEOWNERS file the repository carries, read as rules rather than as text: every pattern in file order with the owners it names, how many rules each owner is named by, 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.	none

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

{
  "guardrails": {
      "failOn": "error",
      "comment": true,
      "checks": [
          {
              "use": "ownership/owners-per-rule@v1",
              "severity": "warning",
              "with": {
                  "minOwners": "1",
                  "maxOwners": "5"
              },
              "exemptions": []
          }
      ]
  }
}

Inputs

Input	Description	Default	Environment variable
minOwners	Fewest owners a rule may name. A rule naming none is left to ownership/no-unowned-rules.	1	GUARDRAIL_INPUT_MINOWNERS
maxOwners	Most owners a rule may name. 0 means no ceiling.	5	GUARDRAIL_INPUT_MAXOWNERS

How to fix

Adjust the rules named in the violations. One owner is a single point of failure: when they are on leave the path is unreviewable. A long list is the opposite failure, because the forge requests all of them and each assumes another will pick it up.

A team owner counts as one:

/api/   @acme/backend

which is usually the right answer, because membership then lives in the team rather than in this file.

More in ownership

• ownership/catch-all-rule. CODEOWNERS declares a rule matching every path, so a file nobody thought about still has an owner.
• ownership/codeowners-parses. Every line of CODEOWNERS that is not a comment reads as a rule, so no ownership is silently lost to a line the forge ignores.
• ownership/codeowners-present. The repository carries a CODEOWNERS file naming at least one rule, so every change has somebody to review it.
• ownership/no-unowned-rules. No rule in CODEOWNERS names an empty set of owners, which would take ownership away from everything it matches.
• ownership/team-owned. Every rule in CODEOWNERS names at least one team, so ownership survives the people currently in it.

All 6 ownership guardrails