pr-kind-label.yaml

name: Apply kind/area labels and milestone from PR body

on:
  pull_request_target:
    types: [opened, edited, reopened]
    branches:
      - main

jobs:
  kind-labels:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - name: Sync kind labels
        env:
          GH_TOKEN: ${{ github.token }}
          PR_BODY: ${{ github.event.pull_request.body }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
          REPO: ${{ github.repository }}
        run: |
          # Escape percent sequences before echoing body derived text into a
          # ::warning:: so it cannot forge additional workflow commands.
          esc() { local s=$1; s=${s//'%'/%25}; s=${s//$'\r'/%0D}; s=${s//$'\n'/%0A}; printf '%s' "$s"; }

          # Extract /kind values from PR body. Absence of a directive is a no-op
          # to avoid wiping kind/* labels set by maintainers through the UI.
          kinds=$(printf '%s' "$PR_BODY" | tr -d '\r' | sed -n 's|^/kind[[:space:]][[:space:]]*||p' | \
            sed 's|[[:space:]]*$||' | sed '/^$/d' | sort -u)
          [ -z "$kinds" ] && exit 0

          # Validate every requested label before mutating. Removing first and
          # failing to add a mistyped label would leave the PR with no kind/*.
          existing=$(gh label list --repo "$REPO" --limit 200 --json name -q '.[].name')
          unknown=$(printf '%s\n' "$kinds" | while IFS= read -r kind; do
            printf '%s\n' "$existing" | grep -qxF "kind/$kind" || printf "kind/%s " "$kind"
          done)
          if [ -n "$unknown" ]; then
            echo "::warning::Unknown label(s) $(esc "${unknown% }"), skipping kind sync"
            exit 0
          fi

          # Remove existing kind/* labels
          gh pr view "$PR_NUMBER" --repo "$REPO" --json labels \
            -q '.labels[].name | select(startswith("kind/"))' | \
            while IFS= read -r label; do
              gh pr edit "$PR_NUMBER" --repo "$REPO" --remove-label "$label" || echo "::warning::Failed to remove label '$(esc "$label")'"
            done

          printf '%s\n' "$kinds" | \
            while IFS= read -r kind; do
              gh pr edit "$PR_NUMBER" --repo "$REPO" --add-label "kind/$kind" || \
                echo "::warning::Label 'kind/$(esc "$kind")' not found in repository"
            done

      - name: Set area labels
        env:
          GH_TOKEN: ${{ github.token }}
          PR_BODY: ${{ github.event.pull_request.body }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
          REPO: ${{ github.repository }}
        run: |
          # Escape percent sequences before echoing body derived text into a
          # ::warning:: so it cannot forge additional workflow commands.
          esc() { local s=$1; s=${s//'%'/%25}; s=${s//$'\r'/%0D}; s=${s//$'\n'/%0A}; printf '%s' "$s"; }

          # Absence of a directive is a no-op. Area labels are also set by the
          # /area comment command and clearing here would wipe those.
          areas=$(printf '%s' "$PR_BODY" | tr -d '\r' | sed -n 's|^/area[[:space:]][[:space:]]*||p' | \
            sed 's|[[:space:]]*$||' | sed '/^$/d' | sort -u)
          [ -z "$areas" ] && exit 0

          existing=$(gh label list --repo "$REPO" --limit 200 --json name -q '.[].name')
          unknown=$(printf '%s\n' "$areas" | while IFS= read -r area; do
            printf '%s\n' "$existing" | grep -qxF "area/$area" || printf "area/%s " "$area"
          done)
          if [ -n "$unknown" ]; then
            echo "::warning::Unknown label(s) $(esc "${unknown% }"), skipping area sync"
            exit 0
          fi

          # Remove existing area/* labels
          gh pr view "$PR_NUMBER" --repo "$REPO" --json labels \
            -q '.labels[].name | select(startswith("area/"))' | \
            while IFS= read -r label; do
              gh pr edit "$PR_NUMBER" --repo "$REPO" --remove-label "$label" || echo "::warning::Failed to remove label '$(esc "$label")'"
            done

          printf '%s\n' "$areas" | \
            while IFS= read -r area; do
              gh pr edit "$PR_NUMBER" --repo "$REPO" --add-label "area/$area" || \
                echo "::warning::Label 'area/$(esc "$area")' not found in repository"
            done

      - name: Set milestone
        env:
          GH_TOKEN: ${{ github.token }}
          PR_BODY: ${{ github.event.pull_request.body }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
          REPO: ${{ github.repository }}
        run: |
          # Escape percent sequences before echoing body derived text into a
          # ::warning:: so it cannot forge additional workflow commands.
          esc() { local s=$1; s=${s//'%'/%25}; s=${s//$'\r'/%0D}; s=${s//$'\n'/%0A}; printf '%s' "$s"; }

          # Use the last /milestone directive in the PR body
          milestone=$(printf '%s' "$PR_BODY" | tr -d '\r' | sed -n 's|^/milestone[[:space:]][[:space:]]*||p' | \
             sed 's|[[:space:]]*$||' | sed '/^$/d' | tail -n 1)
          [ -z "$milestone" ] && exit 0
          gh pr edit "$PR_NUMBER" --repo "$REPO" --milestone "$milestone" || \
            echo "::warning::Milestone '$(esc "$milestone")' not found in repository"