Bazel release process scripts

Those scripts are made to handle the soon to be Bazel
release process. It is still missing the CI part that
deploys built artifacts and sends announcement mails.

It uses the RELNOTES: tag (RELNOTES for a simple change,
RELNOTES[NEW] for a new feature, RELNOTES[INC] for an
incompatible change) to create the CHANGELOG.md file.

The main entry point is scripts/release/release.sh
and should be the only script called directly.

--
Change-Id: I6e066fda4d862ce793cc03dc8bdf0b8cb34f7c2c
Reviewed-on: https://bazel-review.googlesource.com/#/c/1580/
MOS_MIGRATED_REVID=99282250

1 files changed, 338 insertions, 0 deletions

diff --git a/scripts/release/release.sh b/scripts/release/release.sh
new file mode 100755
index 0000000000..bebc2114d5
--- /dev/null
+++ b/scripts/release/release.sh
@@ -0,0 +1,338 @@
+#!/bin/bash -eu
+
+# Copyright 2015 Google Inc. All rights reserved.
+#
+# 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.
+
+# Generate the release branches and handle the release tags.
+
+set -eu
+
+# Repositories to push the release branch and the release tag.
+: ${RELEASE_REPOSITORIES:="https://github.com/google/bazel"}
+
+# Repositories to push the master branch
+: ${MASTER_REPOSITORIES:="https://github.com/google/bazel https://bazel.googlesource.com/bazel"}
+
+# Name of the default editor
+: ${EDITOR=vi}
+
+# Author of the release commits
+: ${RELEASE_AUTHOR="Bazel Release System <noreply@google.com>"}
+
+# Load relnotes.sh
+SCRIPT_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+source ${SCRIPT_DIR}/relnotes.sh
+
+# Load common.sh
+source ${SCRIPT_DIR}/common.sh
+
+# Editing release notes info for the user
+RELEASE_NOTE_MESSAGE='# Editing release notes
+# Modify the release notes to make them suitable for the release.
+# Every line starting with a # will be removed as well as every
+# empty line at the start and at the end.
+'
+
+# Set the release name $1 (and eventually the candidate number $2).
+function set_release_name() {
+  git notes --ref=release remove 2>/dev/null || true
+  git notes --ref=release-candidate remove 2>/dev/null || true
+  git notes --ref=release append -m "$1"
+  [ -z "${2-}" ] || git notes --ref=release-candidate append -m "$2"
+}
+
+# Trim empty lines at the beginning and the end of the buffer.
+function trim_empty_lines() {
+  local f="$(echo $'\f')"  # linefeed because OSX sed does not support \f
+  # Replace all new line by a linefeed, then using sed, remove the leading
+  # and trailing linefeeds and convert them back to newline
+  tr '\n' '\f' | sed -e "s/^$f*//" -e "s/$f*$//" | tr '\f' '\n'
+}
+
+# Launch the editor and return the edited release notes
+function release_note_editor() {
+  local tmpfile="$1"
+  local origin_branch="$2"
+  local branch_name="${3-}"
+  $EDITOR ${tmpfile} || {
+    echo "Editor failed, cancelling release creation..." >&2
+    git checkout -q ${origin_branch} >/dev/null
+    [ -z "${branch_name}" ] || git branch -D ${branch_name}
+    exit 1
+  }
+  # Stripping the release notes
+  local relnotes="$(cat ${tmpfile} | grep -v '^#' | trim_empty_lines)"
+  if [ -z "${relnotes}" ]; then
+    echo "Release notes are empty, cancelling release creation..." >&2
+    git checkout -q ${origin_branch} >/dev/null
+    [ -z "${branch_name}" ] || git branch -D ${branch_name}
+    exit 1
+  fi
+  echo "${relnotes}" >${tmpfile}
+}
+
+# Create the release commit by changing the CHANGELOG file
+function create_release_commit() {
+  local release_title="$1"
+  local release_name="$2"
+  local relnotes="$3"
+  local tmpfile="$4"
+  local baseline="$5"
+  shift 5
+  local cherrypicks=$@
+  local changelog_path="$PWD/CHANGELOG.md"
+
+  version_info=$(create_revision_information $baseline $cherrypicks)
+  # CHANGELOG.md
+  cat >${tmpfile} <<EOF
+## ${release_title}
+
+EOF
+  if [ -n "${version_info}" ]; then
+    cat >>${tmpfile} <<EOF
+\`\`\`
+${version_info}
+\`\`\`
+EOF
+  fi
+  cat >>${tmpfile} <<EOF
+
+${relnotes}
+EOF
+
+  if [ -f "${changelog_path}" ]; then
+    cat "${changelog_path}" >>${tmpfile}
+  fi
+  cat ${tmpfile} > ${changelog_path}
+  git add ${changelog_path}
+  # Commit message
+  cat >${tmpfile} <<EOF
+${release_title}
+
+${version_info}
+
+${relnotes}
+EOF
+  git commit -F ${tmpfile} --no-edit --author "${RELEASE_AUTHOR}"
+}
+
+function apply_cherry_picks() {
+  echo "Applying cherry-picks"
+  # Apply cherry-picks
+  for i in $@; do
+    local previous_head="$(git rev-parse HEAD)"
+    echo "  Cherry-picking $i"
+    git cherry-pick $i >/dev/null || {
+      echo "Failed to cherry-pick $i. please resolve the conflict and exit." >&2
+      echo "  Use 'git cherry-pick --abort; exit' to abort the cherry-picks." >&2
+      echo "  Use 'git cherry-pick --continue; exit' to resolve the conflict." >&2
+      bash
+      if [ "$(git rev-parse HEAD)" == "${previous_head}" ]; then
+        echo "Cherry-pick aborted, aborting the whole command..." >&2
+        return 1
+      fi
+    }
+  done
+  return 0
+}
+
+# Execute the create command:
+#   Create a new release named "$1" with "$2" as the baseline commit.
+function create_release() {
+  local release_name="$1"
+  local baseline="$2"
+  shift 2
+  local origin_branch=$(git_get_branch)
+  local branch_name="release-${release_name}"
+  local release_title="Release ${release_name} ($(date +%Y-%m-%d))"
+  local tmpfile=$(mktemp ${TMPDIR:-/tmp}/relnotes-XXXXXXXX)
+  local tmpfile2=$(mktemp ${TMPDIR:-/tmp}/relnotes-XXXXXXXX)
+  trap 'rm -f ${tmpfile} ${tmpfile2}' EXIT
+
+  # Get the rc number (1 by default)
+  local rc=1
+  if [ -n "$(git branch --list --column ${branch_name})" ]; then
+    rc=$(($(get_release_candidate "${branch_name}")+1))
+  fi
+
+  # Save the changelog so we compute the relnotes against HEAD.
+  git show master:CHANGELOG.md >${tmpfile2} 2>/dev/null || echo >${tmpfile2}
+
+  echo "Creating new release branch ${branch_name} for release ${release_name}"
+  git checkout -B ${branch_name} ${baseline}
+
+  apply_cherry_picks $@ || {
+    git checkout ${origin_branch}
+    git branch -D ${branch_name}
+    exit 1
+  }
+
+  echo "Creating release notes"
+  echo "${RELEASE_NOTE_MESSAGE}" > ${tmpfile}
+  echo "# ${release_title}" >> ${tmpfile}
+  echo >> ${tmpfile}
+  create_release_notes "${tmpfile2}" >> ${tmpfile}
+  release_note_editor ${tmpfile} "${origin_branch}" "${branch_name}"
+  local relnotes="$(cat ${tmpfile})"
+
+  echo "Creating the release commit"
+  create_release_commit "${release_title}" "${release_name}" \
+      "${relnotes}" "${tmpfile}" "${baseline}" $@
+  set_release_name "${release_name}" "${rc}"
+
+  rm -f ${tmpfile} ${tmpfile2}
+  trap - EXIT
+}
+
+# Push the release branch to the release repositories so a release
+# candidate can be created.
+function push_release_candidate() {
+  local branch="$(get_release_branch)"
+  for repo in ${RELEASE_REPOSITORIES}; do
+    git push -f ${repo} +${branch}
+    git push -f ${repo} +refs/notes/release
+    git push -f ${repo} +refs/notes/release-candidate
+  done
+}
+
+# Deletes the release branch after a release or abandoning the release
+function cleanup_branches() {
+  local tag_name=$1
+  local i
+  echo "Destroying the release branches for release ${tag_name}"
+  # Destroy branch, ignoring if it doesn't exists.
+  git branch -D release-${tag_name} &>/dev/null || true
+  for i in $RELEASE_REPOSITORIES; do
+    git push -f $i :release-${tag_name} &>/dev/null || true
+  done
+}
+
+# Releases the current release branch, creating the necessary tag,
+# destroying the release branch, updating the master's CHANGELOG.md
+# and pushing everything to GitHub.
+function do_release() {
+  local branch=$(get_release_branch)
+  local tag_name=$(get_release_name)
+
+  echo -n "You are about to release branch ${branch} in tag ${tag_name}, confirm? [y/N] "
+  read answer
+  if [ "$answer" = "y" -o "$answer" = "Y" ]; then
+    # Remove release "candidate"
+    set_release_name "${tag_name}"
+    echo "Creating the tag"
+    git tag ${tag_name}
+
+    echo "Cherry-picking CHANGELOG.md modification into master"
+    git checkout master
+    # Ensuring we are up to date for master
+    git pull --rebase $(echo "$MASTER_REPOSITORIES" | cut -d " " -f 1) master
+    # We do not cherry-pick because we might have conflict if the baseline
+    # does not contains the latest CHANGELOG.md file, so trick it.
+    local changelog_path="$PWD/CHANGELOG.md"
+    git show ${branch}:CHANGELOG.md >${changelog_path}
+    local tmpfile=$(mktemp ${TMPDIR:-/tmp}/relnotes-XXXXXXXX)
+    trap 'rm -f ${tmpfile}' EXIT
+    git_commit_msg ${branch} >${tmpfile}
+    git add ${changelog_path}
+    git commit -F ${tmpfile} --no-edit --author "${RELEASE_AUTHOR}"
+    rm -f ${tmpfile}
+    trap - EXIT
+
+    echo "Pushing the change to remote repositories"
+    for i in $MASTER_REPOSITORIES; do
+      git push $i +master
+    done
+    for i in $RELEASE_REPOSITORIES; do
+      git push $i +refs/tags/${tag_name}
+      git push $i +refs/notes/release-candidate
+      git push $i +refs/notes/release
+    done
+    cleanup_branches ${tag_name}
+  fi
+}
+
+# Abandon the current release, deleting the branch on the local
+# repository and on GitHub, discarding all changes
+function abandon_release() {
+  local branch_info=$(get_release_branch)
+  local tag_name=$(get_release_name)
+  echo -n "You are about to abandon release ${tag_name}, confirm? [y/N] "
+  read answer
+  if [ "$answer" = "y" -o "$answer" = "Y" ]; then
+    git checkout -q master >/dev/null
+    cleanup_branches ${tag_name}
+  fi
+}
+
+function usage() {
+  cat >&2 <<EOF
+Usage: $1 command [arguments]
+Available commands are:
+  - create RELEASE_NAME BASELINE [COMMIT1 ... COMMITN]: creates a new
+      release branch for release named RELEASE_NAME, cutting it at
+      the commit BASELINE and cherry-picking COMMIT1 ... COMMITN.
+  - push: push the current release branch to release repositories.
+  - release: do the actual release of the current release branch.
+  - abandon: abandon the current release branch.
+
+The typical workflow for the release manager is:
+1. Create the release branch using the decided name for the release
+   (usually a version number). The BASELINE is generally a baseline
+   that has been tested extensively including inside Google.
+2. Push to the repository and wait for the continuous integration
+   to rebuild and deploy the various artifacts and send the annoucement
+   mails about a new release candidate being available.
+3. If necessary, creates a new release branch with the same name to
+   address return from the users and go back to 2.
+4. Either abandon or release the branch depending on if too much
+   problems are reported or if the release is considered viable. The
+   CI system should then rebuild from the tag and deploy the artifact
+   to GitHub and sends the announcement mails about the new release.
+EOF
+   exit 1
+}
+
+git diff-index --quiet HEAD -- || {
+  echo "There are pending changes in this git repository." >&2
+  echo "Please commit or stash them before using that script." >&2
+  exit 1
+}
+
+[ "$(git rev-parse --show-toplevel)" == "$PWD" ] || {
+  echo "You should run this script from the root of the git repository." >&2
+  exit 1
+}
+
+progname=$0
+cmd=${1-}
+shift || usage $progname
+
+case $cmd in
+  create)
+    (( $# >= 2 )) || usage $progname
+    create_release "$@"
+    ;;
+  push)
+    push_release_candidate
+    ;;
+  release)
+    do_release
+    ;;
+  abandon)
+    abandon_release
+    ;;
+  *)
+    usage $progname
+    ;;
+esac