tekton-kind-label.yaml

apiVersion: tekton.dev/v1beta1
kind: Task
metadata:
  name: kind-label
  namespace: tekton-ci
spec:
  description: |
    Verifies that a PR has one valid kind label
  params:
  - name: labels
    description: The labels attached to the Pull Request
  volumes:
  - name: label-config-v2
    configMap:
      name: label-config-v2
  stepTemplate:
    env:
      - name: HOME
        value: /tekton/home
  steps:
  - name: install-pyyaml
    image: python:3-alpine
    script: |
      pip install pyyaml --user
  - name: check-labels
    image: python:3-alpine
    volumeMounts:
      - name: label-config-v2
        mountPath: /etc/config
    env:
      - name: LABELS
        value: $(params.labels)
    script: |
      #!/usr/bin/env python

      import json
      import yaml
      import sys
      import os

      prLabelsText = os.getenv('LABELS')
      prLabels = json.loads(prLabelsText)

      availableLabels = None
      with open("/etc/config/labels.yaml", "r") as stream:
        availableLabels = yaml.safe_load(stream)["default"]["labels"]

      availableKindLabels = {x.get("name"):x.get("description") for x in availableLabels if x.get("name").startswith("kind/")}
      foundKindLabels = set([x.get("name") for x in prLabels if x.get("name").startswith("kind/") and x.get("name")])
      validKindLabels = set([x for x in foundKindLabels if x in availableKindLabels])

      # Check that we have one and only one kind label
      foundLabels = len(validKindLabels)
      if (foundLabels > 1 or foundLabels == 0):
        msg = "Error: {} valid \"kind/*\" labels found".format(foundLabels)
        if foundLabels > 1:
            msg += "({})".format(validKindLabels)
        msg += ", expecting exactly one."
        invalidKindLabels = foundKindLabels - validKindLabels
        if len(invalidKindLabels) > 0:
            msg += " Invalid labels found: {}".format(invalidKindLabels)
        print(msg)
        print("\nAvailable \"kind/*\" labels are:")
        for label, description in availableKindLabels.items():
          print("\t{}: {}".format(label, description))

        # Check failed. Return exit code 1.
        sys.exit(1)
      else:
        print("Exactly one \"kind/*\" label found: {}".format(validKindLabels))
---
apiVersion: tekton.dev/v1beta1
kind: Pipeline
metadata:
  name: tekton-kind-label
spec:
  params:
    - name: checkName
      description: The name of the GitHub check that this pipeline is used for
    - name: gitHubCommand
      description: The command that was used to trigger testing
    - name: labels
      description: The labels attached to the Pull Request
  tasks:
    - name: check-name-matches
      taskRef:
        name: check-name-matches
      params:
        - name: gitHubCommand
          value: $(params.gitHubCommand)
        - name: checkName
          value: $(params.checkName)
    - name: kind-label
      when:  # implicit dependency on the check tasks
      - input: $(tasks.check-name-matches.results.check)
        operator: in
        values: ["passed"]
      taskRef:
        name: "kind-label"
      params:
      - name: labels
        value: $(params.labels)