mergify: support backports automation with labels (#16937)

.buildkite/pull-requests.json

@@ -14,8 +14,10 @@
         "skip_ci_labels": [ ],
         "skip_target_branches": [ ],
         "skip_ci_on_only_changed": [
-          "^docs/",
           "^.github/",
+          "^docs/",
+          "^.mergify.yml$",
+          "^.pre-commit-config.yaml",
           "\\.md$"
         ],
         "always_require_ci_on_changed": [ ]

.ci/Makefile

@@ -0,0 +1,47 @@
+.SILENT:
+MAKEFLAGS += --no-print-directory
+.SHELLFLAGS = -euc
+SHELL = /bin/bash
+
+#######################
+## Templates
+#######################
+## Mergify template
+define MERGIFY_TMPL
+
+  - name: backport patches to $(BRANCH) branch
+    conditions:
+      - merged
+      - base=main
+      - label=$(BACKPORT_LABEL)
+    actions:
+      backport:
+        assignees:
+          - "{{ author }}"
+        branches:
+          - "$(BRANCH)"
+        labels:
+          - "backport"
+        title: "[{{ destination_branch }}] {{ title }} (backport #{{ number }})"
+endef
+
+# Add mergify entry for the new backport label
+.PHONY: mergify
+export MERGIFY_TMPL
+mergify: BACKPORT_LABEL=$${BACKPORT_LABEL} BRANCH=$${BRANCH} PUSH_BRANCH=$${PUSH_BRANCH}
+mergify:
+	@echo ">> mergify"
+	echo "$$MERGIFY_TMPL" >> ../.mergify.yml
+	git add ../.mergify.yml
+	git status
+	if [ ! -z "$$(git status --porcelain)" ]; then \
+		git commit -m "mergify: add $(BACKPORT_LABEL) rule"; \
+		git push origin $(PUSH_BRANCH) ; \
+	fi
+
+# Create GitHub backport label
+.PHONY: backport-label
+backport-label: BACKPORT_LABEL=$${BACKPORT_LABEL}
+backport-label:
+	@echo ">> backport-label"
+	gh label create $(BACKPORT_LABEL) --description "Automated backport with mergify" --color 0052cc --force

.github/workflows/mergify-labels-copier.yml

@@ -0,0 +1,23 @@
+name: mergify backport labels copier
+
+on:
+  pull_request:
+    types:
+      - opened
+
+permissions:
+  contents: read
+
+jobs:
+  mergify-backport-labels-copier:
+    runs-on: ubuntu-latest
+    if: startsWith(github.head_ref, 'mergify/bp/')
+    permissions:
+      # Add GH labels
+      pull-requests: write
+      # See https://github.com/cli/cli/issues/6274
+      repository-projects: read
+    steps:
+      - uses: elastic/oblt-actions/mergify/labels-copier@v1
+        with:
+          excluded-labels-regex: "^backport-*"

.github/workflows/pre-commit.yml

@@ -0,0 +1,18 @@
+name: pre-commit
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+      - 8.*
+      - 9.*
+
+permissions:
+  contents: read
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: elastic/oblt-actions/pre-commit@v1

.github/workflows/version_bumps.yml

@@ -25,9 +25,13 @@ jobs:
   version_bumper:
     name: Bump versions
     runs-on: ubuntu-latest
+    env:
+      INPUTS_BRANCH: "${{ inputs.branch }}"
+      INPUTS_BUMP: "${{ inputs.bump }}"
+      BACKPORT_LABEL: "backport-${{ inputs.branch }}"
     steps:
       - name: Fetch logstash-core team member list
-        uses: tspascoal/get-user-teams-membership@v1
+        uses: tspascoal/get-user-teams-membership@57e9f42acd78f4d0f496b3be4368fc5f62696662 #v3.0.0
         with: 
           username: ${{ github.actor }}
           organization: elastic
@@ -37,14 +41,14 @@ jobs:
         if: ${{ steps.checkUserMember.outputs.isTeamMember == 'false' }}
         run: exit 1
       - name: checkout repo content
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
-          ref: ${{ github.event.inputs.branch }}
+          ref: ${{ env.INPUTS_BRANCH }}
       - run: git config --global user.email "43502315+logstashmachine@users.noreply.github.com"
       - run: git config --global user.name "logstashmachine"
       - run: ./gradlew clean installDefaultGems
-      - run: ./vendor/jruby/bin/jruby -S bundle update --all --${{ github.event.inputs.bump }} --strict
+      - run: ./vendor/jruby/bin/jruby -S bundle update --all --${{ env.INPUTS_BUMP }} --strict
       - run: mv Gemfile.lock Gemfile.jruby-*.lock.release
       - run: echo "T=$(date +%s)" >> $GITHUB_ENV
       - run: echo "BRANCH=update_lock_${T}" >> $GITHUB_ENV
@@ -53,8 +57,21 @@ jobs:
           git add .
           git status
           if [[ -z $(git status --porcelain) ]]; then echo "No changes. We're done."; exit 0; fi
-          git commit -m "Update ${{ github.event.inputs.bump }} plugin versions in gemfile lock" -a
+          git commit -m "Update ${{ env.INPUTS_BUMP }} plugin versions in gemfile lock" -a
           git push origin $BRANCH
+
+      - name: Update mergify (minor only)
+        if: ${{ inputs.bump == 'minor' }}
+        continue-on-error: true
+        run: make -C .ci mergify BACKPORT_LABEL=$BACKPORT_LABEL BRANCH=$INPUTS_BRANCH PUSH_BRANCH=$BRANCH
+
       - name: Create Pull Request
         run: |
-          curl -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" -X POST -d "{\"title\": \"bump lock file for ${{ github.event.inputs.branch }}\",\"head\": \"${BRANCH}\",\"base\": \"${{ github.event.inputs.branch }}\"}" https://api.github.com/repos/elastic/logstash/pulls
+          curl -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" -X POST -d "{\"title\": \"bump lock file for ${{ env.INPUTS_BRANCH }}\",\"head\": \"${BRANCH}\",\"base\": \"${{ env.INPUTS_BRANCH }}\"}" https://api.github.com/repos/elastic/logstash/pulls
+
+      - name: Create GitHub backport label (Mergify) (minor only)
+        if: ${{ inputs.bump == 'minor' }}
+        continue-on-error: true
+        run: make -C .ci backport-label BACKPORT_LABEL=$BACKPORT_LABEL
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.mergify.yml

@@ -0,0 +1,114 @@
+pull_request_rules:
+  - name: ask to resolve conflict
+    conditions:
+      - conflict
+    actions:
+      comment:
+        message: |
+          This pull request is now in conflicts. Could you fix it @{{author}}? 🙏
+          To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/
+          ```
+          git fetch upstream
+          git checkout -b {{head}} upstream/{{head}}
+          git merge upstream/{{base}}
+          git push upstream {{head}}
+          ```
+
+  - name: notify the backport policy
+    conditions:
+      - -label~=^backport
+      - base=main
+    actions:
+      comment:
+        message: |
+          This pull request does not have a backport label. Could you fix it @{{author}}? 🙏
+          To fixup this pull request, you need to add the backport labels for the needed
+          branches, such as:
+          * `backport-8./d` is the label to automatically backport to the `8./d` branch. `/d` is the digit.
+          * `backport-8.x` is the label to automatically backport to the `8.x` branch.
+
+  - name: add backport-8.x for the all the PRs targeting main if no skipped or assigned already
+    conditions:
+      - -label~=^(backport-skip|backport-8.x)$
+      - base=main
+    actions:
+      comment:
+        message: |
+          `backport-8.x` has been added to help with the transition to the new branch `8.x`.
+          If you don't need it please use `backport-skip` label.
+      label:
+        add:
+          - backport-8.x
+
+  - name: remove backport-skip label
+    conditions:
+      - label~=^backport-\d
+    actions:
+      label:
+        remove:
+          - backport-skip
+
+  - name: remove backport-8.x label if backport-skip is present
+    conditions:
+      - label~=^backport-skip
+    actions:
+      label:
+        remove:
+          - backport-8.x
+
+  - name: notify the backport has not been merged yet
+    conditions:
+      - -merged
+      - -closed
+      - author=mergify[bot]
+      - "#check-success>0"
+      - schedule=Mon-Mon 06:00-10:00[Europe/Paris]
+    actions:
+      comment:
+        message: |
+          This pull request has not been merged yet. Could you please review and merge it @{{ assignee | join(', @') }}? 🙏
+
+  - name: backport patches to 8.x branch
+    conditions:
+      - merged
+      - base=main
+      - label=backport-8.x
+    actions:
+      backport:
+        assignees:
+          - "{{ author }}"
+        branches:
+          - "8.x"
+        labels:
+          - "backport"
+        title: "[{{ destination_branch }}] {{ title }} (backport #{{ number }})"
+
+  - name: backport patches to 8.16 branch
+    conditions:
+      - merged
+      - base=main
+      - label=backport-8.16
+    actions:
+      backport:
+        assignees:
+          - "{{ author }}"
+        branches:
+          - "8.16"
+        labels:
+          - "backport"
+        title: "[{{ destination_branch }}] {{ title }} (backport #{{ number }})"
+
+  - name: backport patches to 8.17 branch
+    conditions:
+      - merged
+      - base=main
+      - label=backport-8.17
+    actions:
+      backport:
+        assignees:
+          - "{{ author }}"
+        branches:
+          - "8.17"
+        labels:
+          - "backport"
+        title: "[{{ destination_branch }}] {{ title }} (backport #{{ number }})"

.pre-commit-config.yaml

@@ -0,0 +1,6 @@
+repos:
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.6.0
+    hooks:
+    -   id: check-merge-conflict
+        args: ['--assume-in-merge']