From 39d30ef77ad0fc0629b627e72851ca3ca10693e8 Mon Sep 17 00:00:00 2001
From: Madhu Rajanna <madhupr007@gmail.com>
Date: Fri, 27 Sep 2019 13:50:12 +0530
Subject: [PATCH] Add mergify rule to auto merge backported PR

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>
(cherry picked from commit 136d81b736f59f787c5814a540b2e33474617c42)
---
 .mergify.yml              | 24 ++++++++++++++++++++++++
 docs/development-guide.md | 10 ++++++++++
 2 files changed, 34 insertions(+)

diff --git a/.mergify.yml b/.mergify.yml
index 262235c83..822f3b491 100644
--- a/.mergify.yml
+++ b/.mergify.yml
@@ -19,3 +19,27 @@ pull_request_rules:
         strict: smart
       dismiss_reviews: {}
       delete_head_branch: {}
+  - name: backport patches to release branch
+    conditions:
+      - base=master
+      - label=backport-to-release-v1.2.0
+    actions:
+      backport:
+        branches:
+          - release-v1.2.0
+  # automerge backports if CI successfully ran
+  - name: automerge backport release-v1.2.0
+    conditions:
+      - author=mergify[bot]
+      - base=release-v1.2.0
+      - label!=DNM
+      - "#changes-requested-reviews-by=0"
+      - "#approved-reviews-by>=1"
+      - "status-success=continuous-integration/travis-ci/pr"
+    actions:
+      merge:
+        method: rebase
+        rebase_fallback: merge
+        strict: smart
+      dismiss_reviews: {}
+      delete_head_branch: {}
diff --git a/docs/development-guide.md b/docs/development-guide.md
index 24bd14843..ab090451e 100644
--- a/docs/development-guide.md
+++ b/docs/development-guide.md
@@ -89,3 +89,13 @@ need to be met before it will be merged:
 
 When the criteria are met, a project maintainer can merge your changes into
 the project's master branch.
+
+The flow for getting a fix into a release branch is:
+
+1. Open a PR to merge the changes to master following the process outlined above.
+1. Add the backport label to that PR such as `backport-to-release-vX.Y.Z`
+1. After your PR is merged to master, the mergify bot will automatically open a
+   PR with your commits backported to the release branch
+1. If there are any conflicts you will need to resolve them by pulling the
+   branch, resolving the conflicts and force push back the branch
+1. After the CI is green, the bot will automatically merge the backport PR.