From f0cffa7300cec037fd5bf8adb40a2657f3af3bda Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Sat, 17 Aug 2024 08:31:41 +0200
Subject: [PATCH] replace backport github action with mergify

The current backport action cannot automerge because
the github action bot does not trigger github CI actions.
Mergify instead does not have this limitation and can also
use a merge queue.

On top we have now a declarative configuration to allow
contributers to add new tests to required without having access
to the github org.

An example pull request and backport can be seen here:

https://github.com/Mic92/nix-1/pull/4

and here:

https://github.com/Mic92/nix-1/pull/5

To complete the setup the mergify app must be enabled for this repository.
It's already installed in the nixos organization for nixos-hardware and
other repositories.

(cherry picked from commit 80f20fa4cb75ad48d74047ca060869bb9138f776)
---
 .github/workflows/backport.yml | 32 ------------
 .mergify.yml                   | 92 ++++++++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+), 32 deletions(-)
 delete mode 100644 .github/workflows/backport.yml
 create mode 100644 .mergify.yml

diff --git a/.github/workflows/backport.yml b/.github/workflows/backport.yml
deleted file mode 100644
index dd110de6c..000000000
--- a/.github/workflows/backport.yml
+++ /dev/null
@@ -1,32 +0,0 @@
-name: Backport
-on:
-  pull_request_target:
-    types: [closed, labeled]
-permissions:
-  contents: read
-jobs:
-  backport:
-    name: Backport Pull Request
-    permissions:
-      # for zeebe-io/backport-action
-      contents: write
-      pull-requests: write
-    if: github.repository_owner == 'NixOS' && github.event.pull_request.merged == true && (github.event_name != 'labeled' || startsWith('backport', github.event.label.name))
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          ref: ${{ github.event.pull_request.head.sha }}
-          # required to find all branches
-          fetch-depth: 0
-      - name: Create backport PRs
-        # should be kept in sync with `version`
-        uses: zeebe-io/backport-action@v3.0.2
-        with:
-          # Config README: https://github.com/zeebe-io/backport-action#backport-action
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-          github_workspace: ${{ github.workspace }}
-          pull_description: |-
-            Automatic backport to `${target_branch}`, triggered by a label in #${pull_number}.
-          # should be kept in sync with `uses`
-          version: v0.0.5
diff --git a/.mergify.yml b/.mergify.yml
new file mode 100644
index 000000000..663c45d92
--- /dev/null
+++ b/.mergify.yml
@@ -0,0 +1,92 @@
+queue_rules:
+  - name: default
+    # all required tests need to go here
+    merge_conditions:
+      - check-success=installer
+      - check-success=installer_test (macos-latest)
+      - check-success=installer_test (ubuntu-latest)
+      - check-success=tests (macos-latest)
+      - check-success=tests (ubuntu-latest)
+      - check-success=vm_tests
+    merge_method: rebase
+    batch_size: 5
+
+pull_request_rules:
+  - name: merge using the merge queue
+    conditions:
+      - base=master
+      - label~=merge-queue|dependencies
+    actions:
+      queue: {}
+
+# The rules below will first create backport pull requests and put those in a merge queue.
+
+  - name: backport patches to 2.18
+    conditions:
+      - label=backport 2.18-maintenance
+    actions:
+      backport:
+        branches:
+          - 2.18-maintenance
+        labels:
+          - merge-queue
+
+  - name: backport patches to 2.19
+    conditions:
+      - label=backport 2.19-maintenance
+    actions:
+      backport:
+        branches:
+          - 2.19-maintenance
+        labels:
+          - merge-queue
+
+  - name: backport patches to 2.20
+    conditions:
+      - label=backport 2.20-maintenance
+    actions:
+      backport:
+        branches:
+          - 2.20-maintenance
+        labels:
+          - merge-queue
+
+  - name: backport patches to 2.21
+    conditions:
+      - label=backport 2.21-maintenance
+    actions:
+      backport:
+        branches:
+          - 2.21-maintenance
+        labels:
+          - merge-queue
+
+  - name: backport patches to 2.22
+    conditions:
+      - label=backport 2.22-maintenance
+    actions:
+      backport:
+        branches:
+          - 2.22-maintenance
+        labels:
+          - merge-queue
+
+  - name: backport patches to 2.23
+    conditions:
+      - label=backport 2.23-maintenance
+    actions:
+      backport:
+        branches:
+          - 2.23-maintenance
+        labels:
+          - merge-queue
+
+  - name: backport patches to 2.24
+    conditions:
+      - label=backport 2.24-maintenance
+    actions:
+      backport:
+        branches:
+          - "2.24-maintenance"
+        labels:
+          - merge-queue