Merge pull request #25472 from gnossen/backport_automation

Add Script to Backport PRs to Multiple Branches

tools/release/backport_pr.sh

@@ -0,0 +1,103 @@
+#!/bin/bash
+#Copyright 2021 The gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -euo pipefail
+
+ensure_command () {
+  if command -v "$1" 1>/dev/null 2>&1; then
+    return 0
+  else
+    echo "$1 is not installed. Please install it to proceed." 1>&2
+    exit 1
+  fi
+}
+
+ensure_command "curl"
+ensure_command "egrep"
+ensure_command "hub"
+ensure_command "jq"
+
+if [ -z "$GITHUB_TOKEN" ]; then
+  echo "A GitHub token is required to run this script. See " \
+         "https://docs.github.com/en/github/authenticating-to-github/creating-a-personal-access-token" \
+         " for more information" >/dev/stderr
+  exit 1
+fi
+
+if [ "$#" != "4" ]; then
+  echo "USAGE: $0 PR_NUMBER GITHUB_USER BACKPORT_BRANCHES REVIEWERS" >/dev/stderr
+  echo "   PR_NUMBER: The number for the PR to be backported." >/dev/stderr
+  echo "   GITHUB_USER: Your GitHub username." >/dev/stderr
+  echo "   BACKPORT_BRANCHES: A space-separated list of branches to which to backport." >/dev/stderr
+  echo "   REVIEWERS: A comma-separated list of users add as reviewers and assignees." >/dev/stderr
+  echo "" >/dev/stderr
+  echo "Example: $0 25456 gnossen \"v1.30.x v1.31.x v1.32.x v1.33.x v1.34.x v1.35.x v1.36.x\" \"menghanl,gnossen\""
+  exit 1
+fi
+
+echo "This script will create a collection of backport PRs. Make sure the PR to" \
+       " backport has already been merged. You will probably " \
+       " have to touch your gnubby a frustrating number of times. C'est la vie."
+printf "Press any key to continue."
+read -r RESPONSE </dev/tty
+printf "\n"
+
+PR_NUMBER="$1"
+GITHUB_USER="$2"
+
+BACKPORT_BRANCHES="$3"
+
+REVIEWERS="$4"
+
+PR_DATA=$(curl -s -u "$GITHUB_USER:$GITHUB_TOKEN" \
+          -H "Accept: application/vnd.github.v3+json" \
+          "https://api.github.com/repos/grpc/grpc/pulls/$PR_NUMBER")
+
+MERGE_COMMIT=$(echo "$PR_DATA" | jq -r '.merge_commit_sha')
+PR_TITLE=$(echo "$PR_DATA" | jq -r '.title')
+PR_DESCRIPTION=$(echo "$PR_DATA" | jq -r '.body')
+LABELS=$(echo "$PR_DATA" | jq -r '.labels | map(.name) | join(",")')
+
+set -x
+
+git fetch origin
+
+BACKPORT_PRS=""
+for BACKPORT_BRANCH in $BACKPORT_BRANCHES; do
+  echo "Backporting $MERGE_COMMIT to $BACKPORT_BRANCH."
+
+  git checkout "origin/$BACKPORT_BRANCH"
+
+  BRANCH_NAME="backport_${PR_NUMBER}_to_${BACKPORT_BRANCH}"
+
+  # To make the script idempotent.
+  git branch -D "$BRANCH_NAME" || true
+  git checkout "$BACKPORT_BRANCH"
+  git checkout -b "$BRANCH_NAME"
+
+  git cherry-pick -m 1 "$MERGE_COMMIT"
+  BACKPORT_PR=$(hub pull-request -p -m "[Backport] $PR_TITLE" \
+                  -m "*Beep boop. This is an automatically generated backport of #${PR_NUMBER}.*" \
+                  -m "$PR_DESCRIPTION" \
+                  -l "$LABELS" \
+                  -b "$BACKPORT_BRANCH" \
+                  -r "$REVIEWERS" \
+                  -a "$REVIEWERS" | tail -n 1)
+  BACKPORT_PRS+="$BACKPORT_PR\n"
+
+  # TODO: Turn on automerge once the Github API allows it.
+done
+
+printf "Your backport PRs have been created:\n$BACKPORT_PRS"