Comment and Label Matching

Beyond branch and event annotations, Pipelines-as-Code can trigger PipelineRuns based on comments or labels on pull requests. This is useful when you want human-initiated actions – such as typing /merge-pr in a comment – to kick off specific pipelines, or when you want labeling a pull request (for example, with bug) to automatically run a targeted test suite.

Matching on a comment regex

You can trigger a PipelineRun when someone posts a comment on a pull request or a pushed commit by using the annotation pipelinesascode.tekton.dev/on-comment.

Pipelines-as-Code treats the annotation value as a regular expression (regex). It strips leading and trailing whitespace from the comment before matching, so ^ matches the start of the comment text and $ matches the end.

Only newly created comments trigger matching. Edits or updates to existing comments do not trigger the PipelineRun.

Example:

---
apiVersion: tekton.dev/v1beta1
kind: PipelineRun
metadata:
  name: "merge-pr"
  annotations:
    pipelinesascode.tekton.dev/on-comment: "^/merge-pr"

Pipelines-as-Code triggers the merge-pr PipelineRun when a comment on a pull request starts with /merge-pr.

When the on-comment annotation triggers a PipelineRun, Pipelines-as-Code sets the template variable {{ trigger_comment }}. For details, see Accessing the comment triggering the PipelineRun.

The on-comment annotation follows the pull_request Policy rules. Only users listed in the pull_request policy can trigger the PipelineRun.

Matching on pull request labels

You can use the annotation pipelinesascode.tekton.dev/on-label to trigger a PipelineRun when a pull request carries a specific label. For example, to run the PipelineRun match-bugs-or-defect whenever a pull request has the label bug or defect:

metadata:
  name: match-bugs-or-defect
  annotations:
    pipelinesascode.tekton.dev/on-label: "[bug, defect]"
    pipelinesascode.tekton.dev/on-target-branch: "[main]"
    pipelinesascode.tekton.dev/on-event: "[pull_request]"

• The on-label annotation respects the pull_request Policy rules.

• You still need on-target-branch to specify which branch the pull request targets.

• You still need on-event to specify the event type.

• Pipelines-as-Code supports this annotation on GitHub, Forgejo, and GitLab only. Bitbucket Cloud and Bitbucket Data Center do not support pull request labels.

• When you add a label to a pull request, Pipelines-as-Code triggers the matching PipelineRun immediately and does not activate other PipelineRuns that match the same pull request.

• If you push a new commit to the pull request, Pipelines-as-Code triggers the label-matched PipelineRun again as long as the label is still present.

• You can access pull request labels with the dynamic variable {{ pull_request_labels }}. Labels are separated by a Unix newline \n. For example, you can print them in a shell script:

   for i in $(echo -e "{{ pull_request_labels }}");do
   echo $i
   done

Escaping commas in branch names

If a branch name contains a comma, use the HTML escape entity , in place of the literal comma. For example, to match both main and a branch named release,nightly:

pipelinesascode.tekton.dev/on-target-branch: [main, release,nightly]