labeler improvements

Signed-off-by: Jeffrey Sica <me@jeefy.dev>

Author: jeefy

.github/actions/labeler-action/action.yml

@@ -0,0 +1,25 @@
+name: "Labeler Action"
+description: "A reusable action to label issues and PRs using a Docker container."
+
+inputs:
+  owner:
+    description: "The repository owner."
+    required: true
+  repo:
+    description: "The repository name."
+    required: true
+  issue_number:
+    description: "The issue or PR number."
+    required: true
+  comment_body:
+    description: "The body of the comment triggering the action."
+    required: true
+
+runs:
+  using: "docker"
+  image: "ghcr.io/cncf/automation-labeler:main"
+  args:
+    - "${{ inputs.owner }}"
+    - "${{ inputs.repo }}"
+    - "${{ inputs.issue_number }}"
+    - "${{ inputs.comment_body }}"

.github/workflows/labeler-build.yml

@@ -0,0 +1,21 @@
+name: Auto Label Issues and PRs
+
+on:
+  push:
+    branches:
+      - "*"
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v4
+        with:
+          context: ./utilities/labeler
+          file: ./utilities/labeler/Dockerfile
+          push: true
+          tags: cncf/automation-labeler:${{ github.ref_name }}

.github/workflows/labeler.yml

@@ -8,28 +8,10 @@ jobs:
   label:
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout code
-        uses: actions/checkout@v4
-
-      - name: Set up Go
-        uses: actions/setup-go@v5
+      - name: Run labeler action
+        uses: ./github/actions/labeler-action
         with:
-          go-version: '1.22'
-
-      - name: Build labeler
-        run: |
-          cd utilities/labeler
-          go build -o labeler
-
-      - name: Run labeler on comment
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          cd utilities/labeler
-          # Extract command and args from comment body
-          COMMENT_BODY="${{ github.event.comment.body }}"
-          OWNER="${{ github.repository_owner }}"
-          REPO="${{ github.event.repository.name }}"
-          NUMBER="${{ github.event.issue.number }}"
-          # Always run the labeler; all logic is handled in Go
-          ./labeler "$OWNER" "$REPO" "$NUMBER" "$COMMENT_BODY"
+          owner: ${{ github.repository_owner }}
+          repo: ${{ github.event.repository.name }}
+          issue_number: ${{ github.event.issue.number }}
+          comment_body: ${{ github.event.comment.body }}

utilities/labeler/Dockerfile

@@ -0,0 +1,29 @@
+# Use the official Golang image as a base image
+FROM golang:1.24.5 AS builder
+
+# Set the working directory
+WORKDIR /app
+
+# Copy go.mod and go.sum files
+COPY go.mod go.sum ./
+
+# Download dependencies
+RUN go mod download
+
+# Copy the rest of the application code
+COPY . .
+
+# Build the Go binary
+RUN go build -o labeler main.go
+
+# Use a minimal base image for the final container
+FROM scratch
+
+# Set the working directory
+WORKDIR /app
+
+# Copy the binary from the builder stage
+COPY --from=builder /app/labeler /app/labeler
+
+# Set the entrypoint
+ENTRYPOINT ["/app/labeler"]

utilities/labeler/main.go

@@ -152,9 +152,67 @@ func indexOf(s, substr string) int {
 	return strings.Index(s, substr)
 }
 
+func ensureLabelExists(ctx context.Context, client *github.Client, owner, repo, labelName, color, description string) {
+	// Fetch existing labels
+	existingLabels, _, err := client.Issues.ListLabels(ctx, owner, repo, nil)
+	if err != nil {
+		log.Fatalf("failed to fetch labels: %v", err)
+	}
+
+	// Check if the label already exists
+	for _, lbl := range existingLabels {
+		if lbl.GetName() == labelName {
+			// Update label if color or description differs
+			if lbl.GetColor() != color || lbl.GetDescription() != description {
+				_, _, err := client.Issues.EditLabel(ctx, owner, repo, labelName, &github.Label{
+					Name:        &labelName,
+					Color:       &color,
+					Description: &description,
+				})
+				if err != nil {
+					log.Printf("failed to update label %s: %v", labelName, err)
+				}
+			}
+			return
+		}
+	}
+
+	// Create the label if it doesn't exist
+	_, _, err = client.Issues.CreateLabel(ctx, owner, repo, &github.Label{
+		Name:        &labelName,
+		Color:       &color,
+		Description: &description,
+	})
+	if err != nil {
+		log.Printf("failed to create label %s: %v", labelName, err)
+	}
+}
+
 func applyLabel(ctx context.Context, client *github.Client, owner, repo string, issueNum int, label string) {
 	fmt.Printf("Applying label: %s\n", label)
-	_, _, err := client.Issues.AddLabelsToIssue(ctx, owner, repo, issueNum, []string{label})
+
+	// Fetch existing labels
+	existingLabels, _, err := client.Issues.ListLabels(ctx, owner, repo, nil)
+	if err != nil {
+		log.Printf("failed to fetch labels: %v", err)
+		return
+	}
+
+	// Check if the label exists
+	labelExists := false
+	for _, lbl := range existingLabels {
+		if lbl.GetName() == label {
+			labelExists = true
+			break
+		}
+	}
+
+	if !labelExists {
+		log.Printf("label %s does not exist, skipping application", label)
+		return
+	}
+
+	_, _, err = client.Issues.AddLabelsToIssue(ctx, owner, repo, issueNum, []string{label})
 	if err != nil {
 		log.Printf("failed to apply label %s: %v", label, err)
 	}