From efd41a9a27d38e445c64024d32b9dc6ab3e3e3ef Mon Sep 17 00:00:00 2001
From: Stian Thorgersen <stianst@gmail.com>
Date: Wed, 29 Nov 2023 05:52:49 +0100
Subject: [PATCH] Add script to help with backporting PRs to release branches
 (#24015)

Signed-off-by: Jon Koops <jonkoops@gmail.com>
Signed-off-by: stianst <stianst@gmail.com>
Co-authored-by: Jon Koops <jonkoops@gmail.com>
---
 .github/scripts/pr-backport.sh | 85 ++++++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100755 .github/scripts/pr-backport.sh

diff --git a/.github/scripts/pr-backport.sh b/.github/scripts/pr-backport.sh
new file mode 100755
index 00000000000..2304e479611
--- /dev/null
+++ b/.github/scripts/pr-backport.sh
@@ -0,0 +1,85 @@
+#!/bin/bash -e
+
+TARGET_REMOTE=upstream
+KEYCLOAK_REPO=https://github.com/keycloak/keycloak
+
+PR=$1
+TARGET=$2
+
+function echo_header() {
+  echo ""
+  echo "======================================================================="
+  echo "$1"
+  echo "-----------------------------------------------------------------------"
+}
+
+function error() {
+  echo "======================================================================="
+  echo "Error"
+  echo "-----------------------------------------------------------------------"
+  echo "$1"
+  echo ""
+  exit 1
+}
+
+if ! [ -x "$(command -v gh)" ]; then
+  error "The GitHub CLI is not installed. See: https://github.com/cli/cli#installation"
+fi
+
+if ! [ -x "$(command -v jq)" ]; then
+  error "The jq CLI is not installed. See: https://jqlang.github.io/jq/download/"
+fi
+
+if [ "$PR" == "" ] || [ "$TARGET" == "" ]; then
+  error "Usage: gh-backport-pr.sh <PR NUMBER> <TARGET MAJOR.MINOR>"
+fi
+
+TARGET_BRANCH=release/$TARGET
+
+echo_header "Fetching '$TARGET_REMOTE' remote."
+git fetch $TARGET_REMOTE
+
+PR_STATE=$(gh pr view $PR --json state 2>/dev/null | jq -r .state)
+
+if [ "$PR_STATE" == "" ]; then
+  error "PR #$PR not found. Make sure the PR exists, and that it's been merged."
+elif [ "$PR_STATE" != "MERGED" ]; then
+  error "PR #$PR not merged yet. Only merged PRs can be backported."
+fi
+
+MERGE_COMMIT=$(gh pr view $PR --json mergeCommit | jq -r .mergeCommit.oid)
+
+if [ "$MERGE_COMMIT" == "" ]; then
+  error "Could not resolve merge commit for PR #$PR"
+fi
+
+PR_BRANCH=backport-$PR-$TARGET
+PR_BODY=$(gh pr view $PR --json body | jq -r .body)
+
+echo_header "Details"
+echo "PR Body:        $PR_BODY"
+echo ""
+echo "PR:             $KEYCLOAK_REPO/pull/$PR"
+echo "Commit:         $KEYCLOAK_REPO/commit/$MERGE_COMMIT"
+echo ""
+echo "PR branch:      $PR_BRANCH"
+echo "Target branch:  $KEYCLOAK_REPO/tree/$TARGET_BRANCH"
+echo ""
+echo -n "Continue (y/n): "
+read PROMPT
+
+if [ "$PROMPT" != "y" ]; then
+  exit 1
+fi
+
+echo_header "Checkout '$TARGET_REMOTE/$TARGET_BRANCH' to '$PR_BRANCH'"
+git checkout $TARGET_REMOTE/$TARGET_BRANCH -B $PR_BRANCH
+
+echo_header "Cherry-pick $MERGE_COMMIT"
+git cherry-pick $MERGE_COMMIT
+
+echo_header "Push '$PR_BRANCH' to 'origin' remote"
+git push origin $PR_BRANCH:$PR_BRANCH --set-upstream
+
+echo_header "Opening web browser to create pull request"
+gh pr create -B $TARGET_BRANCH -f -w