Set up automatic releases

Signed-off-by: Bryan Richter <b@chreekat.net>

Author: chreekat

.github/workflows/monthly-release.yml

@@ -0,0 +1,118 @@
+name: Monthly Release
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: "17 12 1 * *" # At 12:17 on day-of-month 1 (avoid top-of-hour load)
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    if: ${{ github.repository == 'p4lang/p4runtime' && github.ref == 'refs/heads/main' }}
+    outputs:
+      has_commits: ${{ steps.check_commits.outputs.has_commits }}
+    steps:
+      - name: Check for new commits since latest tag
+        id: check_commits
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          REPO="${{ github.repository }}"
+          TAG="$(gh api "repos/${REPO}/tags" --jq '.[0].name' 2>/dev/null || echo '')"
+          if [ -z "$TAG" ]; then
+            echo "No tags found, proceeding with release."
+            echo "has_commits=true" >> $GITHUB_OUTPUT
+          else
+            AHEAD="$(gh api "repos/${REPO}/compare/${TAG}...main" --jq '.ahead_by')"
+            if [ "$AHEAD" -eq 0 ]; then
+              echo "No new commits since $TAG, skipping release."
+              echo "has_commits=false" >> $GITHUB_OUTPUT
+            else
+              echo "$AHEAD new commits since $TAG."
+              echo "has_commits=true" >> $GITHUB_OUTPUT
+            fi
+          fi
+
+  release-pr:
+    needs: check
+    if: needs.check.outputs.has_commits == 'true'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+
+      - name: Increment version number
+        run: perl -i -pe 's/\b(\d+)(?=\D*$)/$1+1/e' VERSION
+
+      - name: Get changelog
+        id: changelog
+        run: |
+          TAG="$(git describe --tags --abbrev=0 2>/dev/null || git rev-list --max-parents=0 HEAD)"
+          GIT_LOG="$(git log $TAG..HEAD --oneline --pretty=format:"- %s [%an]")"
+          CHANGELOG=$(cat << EOF
+          Changelog:
+          $GIT_LOG
+          EOF
+          )
+          CHANGELOG="${CHANGELOG//'#'/''}"
+          echo "content<<EOF" >> "$GITHUB_OUTPUT"
+          echo "$CHANGELOG" >> "$GITHUB_OUTPUT"
+          echo "EOF" >> "$GITHUB_OUTPUT"
+
+      - name: Display changelog
+        run: |
+          cat <<'EOF'
+          ${{ steps.changelog.outputs.content }}
+          EOF
+
+      - name: Get version
+        run: |
+          VERSION="$(cat VERSION)"
+          echo "VERSION=$VERSION" >> $GITHUB_ENV
+
+      - name: Get commit message
+        id: message
+        run: |
+          COMMIT_MSG=$(cat << 'EOF'
+          Release v${{ env.VERSION }}
+
+          ${{ steps.changelog.outputs.content }}
+          EOF
+          )
+          echo "content<<EOF" >> "$GITHUB_OUTPUT"
+          echo "$COMMIT_MSG" >> "$GITHUB_OUTPUT"
+          echo "EOF" >> "$GITHUB_OUTPUT"
+
+      - name: Get pull request body message
+        id: body
+        run: |
+          MSG=$(cat << 'EOF'
+          Auto-generated pull request for version ${{ env.VERSION }}.
+
+          Please use **Squash and merge** to include the changelog in the release message.
+
+          ${{ steps.changelog.outputs.content }}
+          EOF
+          )
+          echo "content<<EOF" >> "$GITHUB_OUTPUT"
+          echo "$MSG" >> "$GITHUB_OUTPUT"
+          echo "EOF" >> "$GITHUB_OUTPUT"
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v8
+        with:
+          base: main
+          add-paths: VERSION
+          reviewers: antoninbas, jafingerhut, smolkaj
+          commit-message: ${{ steps.message.outputs.content }}
+          signoff: false
+          branch: v${{ env.VERSION }}
+          delete-branch: true
+          title: Automated Release v${{ env.VERSION }}
+          body: ${{ steps.body.outputs.content }}

.github/workflows/publish-release.yml

@@ -0,0 +1,54 @@
+name: Publish Release
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+    paths:
+      - "VERSION"
+
+# Cancel any preceding run on the pull request.
+concurrency:
+  group: release-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
+
+jobs:
+  publish:
+    if: ${{ github.repository == 'p4lang/p4runtime' }}
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+
+      - name: Get version
+        run: |
+          VERSION="$(cat VERSION)"
+          TAG="v$(cat VERSION)"
+          echo "VERSION=$VERSION" >> $GITHUB_ENV
+          echo "TAG=$TAG" >> $GITHUB_ENV
+
+      - name: Check if tag exists
+        id: check_tag
+        run: |
+          TAG="${{ env.TAG }}"
+          if git rev-parse "$TAG" >/dev/null 2>&1; then
+            echo "Tag $TAG already exists, skipping release creation."
+            echo "tag_exists=true" >> $GITHUB_OUTPUT
+          else
+            echo "Tag $TAG does not exist."
+            echo "tag_exists=false" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Release
+        if: steps.check_tag.outputs.tag_exists == 'false'
+        uses: softprops/action-gh-release@v2
+        with:
+          tag_name: ${{ env.TAG }}
+          generate_release_notes: true
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

VERSION

@@ -0,0 +1 @@
+1.5.0