new GHA to validate component version PR labels

Author: sarasvoss

.github/workflows/internal_component_version_validation.yml

@@ -0,0 +1,102 @@
+name: Validate PR Version Labels
+
+on:
+  pull_request:
+    branches: [main]
+    types:
+      - opened
+      - synchronize
+      - edited
+      - labeled # important to catch version label additions
+      - unlabeled
+      - reopened
+
+permissions:
+  contents: read
+  pull-requests: read
+
+jobs:
+  validate-version-labels:
+    name: Validate PR Version Labels
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Get all labels on the PR
+        id: get_labels
+        run: |
+          SUMMARY_FILE="$GITHUB_STEP_SUMMARY"
+
+          echo "## PR Labels" >> "$SUMMARY_FILE"
+
+          all_labels=$(jq -r '.pull_request.labels[].name' < "$GITHUB_EVENT_PATH" 2>/dev/null || true)
+
+          if [ -z "$all_labels" ]; then
+            echo "- (none)" >> "$SUMMARY_FILE"
+            echo "::error title=No Labels::No Labels were found on this PR. A version label is required."
+            exit 1
+          else
+            while IFS= read -r lbl; do
+              [ -z "$lbl" ] && continue
+                echo "- \`$lbl\`" >> "$SUMMARY_FILE"
+              done <<< "$all_labels"
+          fi
+
+          # Save labels for later steps
+          {
+            echo "all_labels<<EOF"
+            echo "$all_labels"
+            echo "EOF"
+          } >> "$GITHUB_OUTPUT"
+
+      - name: Filter Version Labels
+        id: filter_labels
+        run: |
+          all_labels="${{ steps.get_labels.outputs.all_labels }}"
+          version_labels=$(echo "$all_labels" | grep -E '^version:(.+):v[0-9]+\.[0-9]+\.[0-9]+$|^version:untracked$' || true)
+
+          if [ -z "$version_labels" ]; then
+            echo "::error title=No Version Labels::No version labels found on this PR. A version label is required."
+            exit 1
+          fi
+
+          echo "$version_labels" >> "$GITHUB_OUTPUT"
+
+      - name: Untrack Label Check
+        id: untracked_check
+        run: |
+          version_labels="${{ steps.filter_labels.outputs.version_labels }}"
+          //TODO check for version:untracked label
+          // error if other version labels are present along with it
+          if echo "$version_labels" | grep -q '^version:untracked$' &&; then
+            if [ "$(echo "$version_labels" | wc -l)" -gt 1 ]; then
+              echo "::error title=Conflicting Version Labels::The label 'version:untracked' cannot be used with other version labels."
+              exit 1
+            fi
+          fi            
+
+      - name: Outcome
+        if: ${{ always() }}
+        env:
+            NO_LABELS: ${{ steps.get_labels.outcome == 'failure' }}
+            NO_VERSION_LABELS: ${{ steps.filter_labels.outcome == 'failure' }}
+            CONFLICTING_LABELS: ${{ steps.untracked_check.outcome == 'failure' }}
+        run: |
+          SUMMARY_FILE="$GITHUB_STEP_SUMMARY"
+          echo "## Validation Outcome" >> "$SUMMARY_FILE"
+
+          if [ "${{ env.NO_LABELS }}" = "true" ]; then
+            echo "❌ No labels found on the PR. Add at least one version label." >> "$SUMMARY_FILE"
+          fi
+          if [ "${{ env.NO_VERSION_LABELS }}" = "true" ]; then
+            echo "❌ No version labels found on the PR. Add at least one version label." >> "$SUMMARY_FILE"
+          fi
+          if [ "${{ env.CONFLICTING_LABELS }}" = "true" ]; then
+            echo "❌ Conflicting version labels found. \`version:untracked\` cannot be used with other version labels)." >> "$SUMMARY_FILE"
+          fi
+
+          echo "> PR must include a version label." >> "$SUMMARY_FILE"
+          echo "> See Version Labeling Policy in VERSIONING.md for details." >> "$SUMMARY_FILE"
+