Fix the check labels job

The check labels job uses the PR pipeline resource to add a comment
to the PR with instructions for developers in case of failure.
That doesn't work though because in case of failure the sync-up side
of the pipeline resource is not processed, so the commit is not
written.

Fix that by removing the pipeline resource and writing the instructions
to the step log instead. The step log is linked in the github status
details through the tekton dashboard.

In future we might extend the github update service to include
support for comments, but that would require support for results on
failure: tektoncd/pipeline#3749

Signed-off-by: Andrea Frittoli <andrea.frittoli@uk.ibm.com>

tekton/ci/jobs/tasks.yaml

@@ -148,13 +148,6 @@ metadata:
   description: |
     Verifies that a PR has one valid kind label
 spec:
-  resources:
-    inputs:
-      - name: pr
-        type: pullRequest
-    outputs:
-      - name: pr
-        type: pullRequest
   params:
   - name: labels
     description: The labels attached to the Pull Request
@@ -163,12 +156,6 @@ spec:
     configMap:
       name: label-config-v2
   steps:
-  - name: copy-pr-to-output
-    image: busybox
-    script: |
-      #!/bin/sh
-      mkdir -p $(outputs.resources.pr.path)
-      cp -r $(inputs.resources.pr.path)/* $(outputs.resources.pr.path)/
   - name: install-pyyaml
     image: python:3-alpine
     script: |
@@ -187,38 +174,31 @@ spec:
 
       prLabelsText = """$(params.labels)"""
       prLabels = json.loads(prLabelsText)
-      labelNames = list(map(lambda e: e["name"], prLabels))
-      kindLabels = list(filter(lambda e: "kind" in e, labelNames))
 
       availableLabels = None
-      with open("/etc/config/labels.yaml", "r") as stream:
+      with open("labels.yaml", "r") as stream:
         availableLabels = yaml.safe_load(stream)["default"]["labels"]
 
-      availableKindLabels = list(filter(lambda e: "kind/" in e["name"], availableLabels))
-      availableKindNamesAndDescriptions = map(lambda e: "`" +str(e["name"])+ "`" + ":  " + str(e["description"]), availableKindLabels)
-
-      comment_template=""
-      if (len(kindLabels) > 1 or len(kindLabels) == 0):
-        comment_template += """
-      **This PR cannot be merged:** expecting exactly one kind/ label
-
-      <details>
-
-      Available `kind/` labels are:
-
-      """
-
-        for i in availableKindNamesAndDescriptions:
-          comment_template += i + "\n"
-
-        comment_template += """
+      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])
 
-      </details>
-      """
-        new_comment_path = "$(outputs.resources.pr.path)/comments/new.json"
-        comment_body = dict(body=comment_template)
-        with open(new_comment_path, "w") as comment:
-          json.dump(comment_body, comment)
+      # 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)
+        sys.exit(1)
+      else:
+        print("Exactly one \"kind/*\" label found: {}".format(validKindLabels[0]))

tekton/ci/jobs/tekton-kind-label.yaml

@@ -11,9 +11,6 @@ spec:
       description: The command that was used to trigger testing
     - name: labels
       description: The labels attached to the Pull Request
-  resources:
-    - name: pr
-      type: pullRequest
   tasks:
   - name: check-kind-label
     conditions:
@@ -28,10 +25,3 @@ spec:
     params:
     - name: labels
       value: $(params.labels)
-    resources:
-      inputs:
-      - name: pr
-        resource: pr
-      outputs:
-      - name: pr
-        resource: pr

tekton/ci/templates/all-template.yaml

@@ -51,15 +51,4 @@ spec:
         - name: checkName
           value: check-pr-has-kind-label
         - name: gitHubCommand
-          value: $(tt.params.gitHubCommand)
-      resources:
-        - name: pr
-          resourceSpec:
-            type: pullRequest
-            params:
-            - name: url
-              value: $(tt.params.pullRequestUrl)
-            secrets:
-            - fieldName: authToken
-              secretName: bot-token-github
-              secretKey: bot-token
+          value: $(tt.params.gitHubCommand)