CASSANDRA-18399: Add a script to prepare merge commands

dev/prepare-merge-commands.sh

@@ -0,0 +1,207 @@
+#!/bin/bash
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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 -e
+
+supported_versions=("3.0" "3.11" "4.0" "4.1" "trunk")
+
+# Read the remote Apache Cassandra repository name
+apache_repository=""
+for r in $(git remote show); do
+  url="$(git remote get-url "$r")"
+  if [[ "$url" == *"apache/cassandra.git" ]]; then
+    apache_repository="$r"
+    break
+  elif [[ "$url" == *"asf/cassandra.git" ]]; then
+    apache_repository="$r"
+  fi
+done
+echo "Remote repositories: "
+git remote -v show
+echo ""
+read -r -e -i "$apache_repository" -p "Enter Apache Cassandra remote repository name: " apache_repository
+git fetch "$apache_repository"
+echo ""
+
+# Read the feature repository and branch
+branch="$(git status -b --porcelain=v2 | grep branch.upstream | cut -f 3 -d ' ')"
+
+if [[ "$branch" =~ ^([^/]*)/(CASSANDRA-[0-9]+).*$ ]]; then
+  repository="${BASH_REMATCH[1]}"
+  ticket="${BASH_REMATCH[2]}"
+fi
+
+read -r -e -i "$repository" -p "Enter a feature repository name: " repository
+read -r -e -i "$ticket" -p "Enter a ticket ID: " ticket
+if [ -z "$repository" ] || [ -z "$ticket" ]; then
+  exit 0
+fi
+echo ""
+
+git fetch "$repository"
+
+# Read all feature branches based on the ticket name
+readarray -t branches < <(git ls-remote --refs -h -q "$repository" | grep "$ticket" | cut -d '/' -f 3 | sort)
+if [[ "${#branches[@]}" == 0 ]]; then
+  echo "Found no feature branches that include a $ticket in name"
+  exit 0
+fi
+
+echo "The following feature branches were found:"
+for branch in "${branches[@]}"; do
+  echo "$branch"
+done
+echo ""
+
+# Read the oldest Cassandra version where the feature should be applied
+matched=0
+while [[ $matched == 0 ]]; do
+  read -r -e -p "What is the oldest target version you want to merge? " oldest_target_version
+  if [[ -z "$oldest_target_version" ]]; then
+    exit 0
+  fi
+
+  feature_versions=()
+  for v in "${supported_versions[@]}"; do
+    if [[ "$v" == "$oldest_target_version" ]]; then
+      matched=1
+    fi
+    if [[ $matched == 1 ]]; then
+      feature_versions+=("$v")
+    fi
+  done
+done
+
+echo "Will merge to the following Cassandra versions:"
+for v in "${feature_versions[@]}"; do
+  echo "$v"
+done
+echo ""
+
+function find_matching_branch() {
+  local infix="$1"
+  for b in "${branches[@]}"; do
+    if [[ "$infix" == "" ]] && [[ "$b" == "$ticket" ]]; then
+      echo "$b"
+      return 0
+    elif [[ "$b" == *"$infix"* ]]; then
+      echo "$b"
+      return 0
+    fi
+  done
+
+  return 1
+}
+
+# Confirm which feature branches are for which Cassandra versions
+feature_branches=()
+target_branches=()
+for v in "${feature_versions[@]}"; do
+  branch=""
+  if [[ "$v" == "trunk" ]]; then
+    target_branches+=("trunk")
+    branch="$(find_matching_branch trunk || find_matching_branch "" || true)"
+  else
+    target_branches+=("cassandra-$v")
+    branch="$(find_matching_branch "$v" || true)"
+  fi
+  read -r -e -i "$branch" -p "Enter branch for version $v or leave empty if there nothing to merge for this version: " branch
+  feature_branches+=("$branch")
+done
+
+# Generate a script
+
+echo ""
+echo ""
+echo ""
+echo "git fetch $apache_repository"
+echo "git fetch $repository"
+
+# Get a subject from the first commit which will serve as a title to be pasted into CHANGES.txt
+first_commit="$(git log --pretty=format:%s --reverse "$apache_repository/${target_branches[0]}..$repository/${feature_branches[0]}" | head -n 1)"
+
+push_command="git push --atomic $apache_repository"
+skipped_branches_found=0
+for i in $(seq 0 $((${#target_branches[@]} - 1))); do
+  echo ""
+  echo ""
+  echo ""
+  echo "# $repository/${feature_branches[$i]} -> ${target_branches[$i]}"
+  echo "# --------------------------------------------------------------------------------------------------------"
+
+  if [[ $i == 0 ]] && [[ "${feature_branches[$i]}" == "" ]]; then
+    # Although we can skip a feature for some versions, we cannot skip it for the oldest version (which is quite obvious)
+    exit 1
+  fi
+
+  # Read the list of commits between the remote head and the feature branch - we need to cherry pick them (or some of them)
+
+  echo "git switch ${target_branches[$i]}"
+  echo "git reset --hard $apache_repository/${target_branches[$i]}"
+  if [[ "${feature_branches[$i]}" == "" ]]; then
+    skipped_branches_found=1
+    # A script for the case where there is no fix for a version
+    echo "git merge -s ours --log --no-edit ${target_branches[$((i - 1))]}"
+  else
+    readarray -t commits < <(git log --reverse --oneline "$apache_repository/${target_branches[$i]}..$repository/${feature_branches[$i]}")
+
+    if [[ $i != 0 ]]; then
+      # When this isn't the oldest version (we want to have only the merge commit)
+      echo "git merge -s ours --log --no-edit ${target_branches[$((i - 1))]}"
+    fi
+
+    for c in $(seq 0 $((${#commits[@]} - 1))); do
+      commit_sha="$(echo "${commits[$c]}" | cut -f 1 -d ' ')"
+      if [[ $i == 0 ]] && [[ $c == 0 ]]; then
+        # we want to have only one feature commit (c == 0), which is in the oldest version (i == 0)
+        echo "git cherry-pick $commit_sha # ${commits[$c]}"
+      else
+        # otherwise we squash the commits to the previous one
+        echo "git cherry-pick -n $commit_sha && git commit -a --amend --no-edit # ${commits[$c]}"
+      fi
+    done
+  fi
+
+  if [[ "$skipped_branches_found" == "0" ]]; then
+    if [[ $i == 0 ]]; then
+      echo "grep '$ticket' CHANGES.txt || sed -E -i '/^[0-9]+\.[0-9]+/{s/.*/&\n\ * $first_commit ($ticket)/;:a;n;ba}' CHANGES.txt"
+    else
+      echo "grep '$ticket' CHANGES.txt || sed -E -i '/^Merged from ${oldest_target_version}/{s/.*/&\n\ * $first_commit ($ticket)/;:a;n;ba}' CHANGES.txt"
+    fi
+    echo "git diff CHANGES.txt"
+  else
+    echo "Update CHANGES.txt by adding the following line:"
+    echo " * $first_commit ($ticket)"
+  fi
+  echo "git add CHANGES.txt"
+  echo "git commit --amend --no-edit"
+
+  echo "(git diff $apache_repository/${target_branches[$i]}..HEAD -- .circleci/ | git apply -R --index) && git commit -a --amend --no-edit # Remove all changes in .circleci directory if you need to"
+
+  echo "git diff --name-only $apache_repository/${target_branches[$i]}..HEAD # print a list of all changes files"
+
+  push_command+=" ${target_branches[$i]}"
+done
+
+echo ""
+echo ""
+echo ""
+echo "$push_command -n"
+
+