git_commit_signed_off

Assert every commit in scope carries a DCO (Developer Certificate of Origin) Signed-off-by: trailer — required by every CNCF / Linux Foundation / kernel-style project. A commit lacking the trailer fires one violation, with the short SHA + subject snippet so you know which to amend (git commit --amend -s or git rebase --signoff).

# HEAD-only: the tip commit must be signed off.
- id: dco
  kind: git_commit_signed_off
  level: error

# Range mode for PR CI: every commit in the PR must be signed off.
- id: pr-dco
  kind: git_commit_signed_off
  since: "{{env.ALINT_BASE_SHA | default('origin/main')}}"
  level: error

The default pattern: is the canonical DCO shape (?m)^Signed-off-by: .+ <.+@.+>$. Override pattern: to enforce a stricter form (e.g. a corporate-domain email). Shares the commit-validation family’s since: / include_merges: semantics and failure modes (silent outside a git repo; a bad since: ref hard-fails with a shallow-clone hint). See variable interpolation for the {{env.X}} form.

Options

Option	Type	Required	Default	Description
include_merges	boolean		false	When validating a range (since: set), include merge commits. Has no effect when since: is unset; combining include_merges: true with no since: is a load-time error.
pattern	string		null	Trailer pattern each commit message must contain. Defaults to the canonical DCO sign-off shape (?m)^Signed-off-by: .+ <.+@.+>$. Override to enforce a stricter form (e.g. a corporate-domain email).
since	string		null	Git ref to use as the base of the commit range. When set, validates every commit in <since>..HEAD instead of just HEAD. Accepts anything git rev-parse does. Use the canonical {{env.X}} interpolation to pass a SHA via an env var, e.g. since: "{{env.ALINT_BASE_SHA | default('origin/main')}}".

Plus the common level, id, and when fields. This rule analyses the whole repository, so it takes no paths. This table is generated from the JSON Schema; option types and defaults are authoritative.