[SPARK-24372][build] Add scripts to help with preparing releases.

The "do-release.sh" script asks questions about the RC being prepared,
trying to find out as much as possible automatically, and then executes
the existing scripts with proper arguments to prepare the release. This
script was used to prepare the 2.3.1 release candidates, so was tested
in that context.

The docker version runs that same script inside a docker image especially
crafted for building Spark releases. That image is based on the work
by Felix C. linked in the bug. At this point is has been only midly
tested.

I also added a template for the vote e-mail, with placeholders for
things that need to be replaced, although there is no automation around
that for the moment. It shouldn't be hard to hook up certain things like
version and tags to this, or to figure out certain things like the
repo URL from the output of the release scripts.

Author: Marcelo Vanzin

dev/create-release/do-release-docker.sh

@@ -0,0 +1,100 @@
+#!/usr/bin/env 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
+SELF=$(cd $(dirname $0) && pwd)
+. "$SELF/release-util.sh"
+
+WORKDIR=
+IMGTAG=latest
+while getopts "d:n:t:" opt; do
+  case $opt in
+    d) WORKDIR="$OPTARG" ;;
+    n) DRY_RUN=1 ;;
+    t) IMGTAG="$OPTARG" ;;
+    ?) error "Invalid option: $OPTARG" ;;
+  esac
+done
+
+if [ -z "$WORKDIR" ] || [ ! -d "$WORKDIR" ]; then
+  error "Work directory (-d) must be defined and exist."
+fi
+
+if [ -d "$WORKDIR/output" ]; then
+  read -p "Output directory already exists. Overwrite and continue? [y/n] " ANSWER
+  if [ "$ANSWER" != "y" ]; then
+    error "Exiting."
+  fi
+fi
+
+cd "$WORKDIR"
+rm -rf "$WORKDIR/output"
+mkdir "$WORKDIR/output"
+
+get_release_info
+
+# Place all RM scripts and necessary data in a local directory that must be defined in the command
+# line. This directory is mounted into the image.
+for f in "$SELF"/*; do
+  if [ -f "$f" ]; then
+    cp "$f" "$WORKDIR"
+  fi
+done
+GPG_KEY_FILE="$WORKDIR/gpg.key"
+fcreate_secure "$GPG_KEY_FILE"
+$GPG --export-secret-key --armor "$GPG_KEY" > "$GPG_KEY_FILE"
+
+run_silent "Building spark-rm image with tag $IMGTAG..." "docker-build.log" \
+  docker build -t "spark-rm:$IMGTAG" --build-arg UID=$UID "$SELF/spark-rm"
+
+# Write the release information to a file with environment variables to be used when running the
+# image.
+ENVFILE="$WORKDIR/env.list"
+fcreate_secure "$ENVFILE"
+
+function cleanup {
+  rm -f "$ENVFILE"
+  rm -f "$GPG_KEY_FILE"
+}
+
+trap cleanup EXIT
+
+cat > $ENVFILE <<EOF
+DRY_RUN=$DRY_RUN
+SKIP_TAG=$SKIP_TAG
+RUNNING_IN_DOCKER=1
+GIT_BRANCH=$GIT_BRANCH
+NEXT_VERSION=$NEXT_VERSION
+RELEASE_VERSION=$RELEASE_VERSION
+RELEASE_TAG=$RELEASE_TAG
+GIT_REF=$GIT_REF
+SPARK_PACKAGE_VERSION=$SPARK_PACKAGE_VERSION
+ASF_USERNAME=$ASF_USERNAME
+GIT_NAME=$GIT_NAME
+GIT_EMAIL=$GIT_EMAIL
+GPG_KEY=$GPG_KEY
+ASF_PASSWORD=$ASF_PASSWORD
+GPG_PASSPHRASE=$GPG_PASSPHRASE
+EOF
+
+echo "Building $RELEASE_TAG; output will be at $WORKDIR/output"
+docker run \
+  --env-file "$ENVFILE" \
+  --volume "$WORKDIR":/opt/spark-rm \
+  "spark-rm:$IMGTAG"

dev/create-release/do-release.sh

@@ -0,0 +1,53 @@
+#!/usr/bin/env 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.
+#
+
+SELF=$(cd $(dirname $0) && pwd)
+. "$SELF/release-util.sh"
+
+while getopts "bn" opt; do
+  case $opt in
+    b) GIT_BRANCH=$OPTARG ;;
+    n) DRY_RUN=1 ;;
+    ?) error "Invalid option: $OPTARG" ;;
+  esac
+done
+
+set -e
+
+if [ "$RUNNING_IN_DOCKER" = "1" ]; then
+  # Inside docker, need to import the GPG key stored in the current directory.
+  echo $GPG_PASSPHRASE | $GPG --passphrase-fd 0 "$SELF/gpg.key"
+else
+  # Outside docker, need to ask for information about the release.
+  get_release_info
+fi
+
+if [ $SKIP_TAG = 0 ]; then
+  run_silent "Creating release tag $RELEASE_TAG..." "tag.log" \
+    "$SELF/release-tag.sh"
+else
+  echo "Skipping tag creation for $RELEASE_TAG."
+fi
+
+run_silent "Building Spark..." "build.log" \
+  "$SELF/release-build.sh" package
+run_silent "Building documentation..." "docs.log" \
+  "$SELF/release-build.sh" docs
+run_silent "Publishing release" "publish.log" \
+  "$SELF/release-build.sh" publish-release

dev/create-release/release-util.sh

@@ -0,0 +1,195 @@
+#!/usr/bin/env 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.
+#
+
+DRY_RUN=${DRY_RUN:-0}
+GPG="gpg --no-tty --batch"
+ASF_REPO="https://git-wip-us.apache.org/repos/asf/spark.git"
+ASF_REPO_WEBUI="https://git-wip-us.apache.org/repos/asf?p=spark.git"
+
+function error {
+  echo "$*"
+  exit 1
+}
+
+function read_config {
+  local PROMPT="$1"
+  local DEFAULT="$2"
+  local REPLY=
+
+  read -p "$PROMPT [$DEFAULT]: " REPLY
+  local RETVAL="${REPLY:-$DEFAULT}"
+  if [ -z "$RETVAL" ]; then
+    error "$PROMPT is must be provided."
+  fi
+  echo "$RETVAL"
+}
+
+function parse_version {
+  grep -e '<version>.*</version>' | \
+    head -n 2 | tail -n 1 | cut -d'>' -f2 | cut -d '<' -f1
+}
+
+function run_silent {
+  local BANNER="$1"
+  shift
+  local LOG_FILE="$1"
+  shift
+
+  echo "=================================="
+  echo "= $BANNER"
+  echo "Command: $@"
+  echo "Log file: $LOG_FILE"
+
+  if [ $DRY_RUN = 0 ]; then
+    "$@" 1>"$LOG_FILE" 2>&1
+  else
+    echo "$@"
+    touch "$LOG_FILE"
+  fi
+
+  local EC=$?
+  if [ $EC != 0 ]; then
+    echo "Command FAILED. Check full logs for details."
+    tail "$LOG_FILE"
+    return $EC
+  fi
+}
+
+function fcreate_secure {
+  local FPATH="$1"
+  rm -f "$FPATH"
+  touch "$FPATH"
+  chmod 600 "$FPATH"
+}
+
+function check_for_tag {
+  curl -s --head --fail "$ASF_REPO_WEBUI;a=commit;h=$1" >/dev/null
+}
+
+function get_release_info {
+  if [ -z "$GIT_BRANCH" ]; then
+    # If no branch is specified, found out the latest branch from the repo.
+    GIT_BRANCH=$(git ls-remote --heads "$ASF_REPO" |
+      grep -v refs/heads/master |
+      awk '{print $2}' |
+      sort -r |
+      head -n 1 |
+      cut -d/ -f3)
+  fi
+
+  export GIT_BRANCH=$(read_config "Branch" "$GIT_BRANCH")
+
+  # Find the current version for the branch.
+  local VERSION=$(curl -s "$ASF_REPO_WEBUI;a=blob_plain;f=pom.xml;hb=refs/heads/$GIT_BRANCH" |
+    parse_version)
+  echo "Current branch version is $VERSION."
+
+  if [[ ! $VERSION =~ .*-SNAPSHOT ]]; then
+    error "Not a SNAPSHOT version: $VERSION"
+  fi
+
+  NEXT_VERSION="$VERSION"
+  RELEASE_VERSION="${VERSION/-SNAPSHOT/}"
+  SHORT_VERSION=$(echo "$VERSION" | cut -d . -f 1-2)
+  local REV=$(echo "$VERSION" | cut -d . -f 3)
+
+  # Find out what rc is being prepared.
+  # - If the current version is "x.y.0", then this is rc1 of the "x.y.0" release.
+  # - If not, need to check whether the previous version has been already released or not.
+  #   - If it has, then we're building rc1 of the current version.
+  #   - If it has not, we're building the next RC of the previous version.
+  local RC_COUNT
+  if [ $REV != 0 ]; then
+    local PREV_REL_REV=$((REV - 1))
+    local PREV_REL_TAG="v${SHORT_VERSION}.${PREV_REL_REV}"
+    if check_for_tag "$PREV_REL_TAG"; then
+      RC_COUNT=1
+      REV=$((REV + 1))
+      NEXT_VERSION="${SHORT_VERSION}-${REV}-SNAPSHOT"
+    else
+      RELEASE_VERSION="${SHORT_VERSION}.${PREV_REL_REV}"
+      RC_COUNT=$(git ls-remote --tags "$ASF_REPO" "v${RELEASE_VERSION}-rc*" | wc -l)
+      RC_COUNT=$((RC_COUNT + 1))
+    fi
+  else
+    REV=$((REV + 1))
+    NEXT_VERSION="${SHORT_VERSION}-${REV}-SNAPSHOT"
+    RC_COUNT=1
+  fi
+
+  export NEXT_VERSION
+  export RELEASE_VERSION=$(read_config "Release" "$RELEASE_VERSION")
+
+  RC_COUNT=$(read_config "RC #" "$RC_COUNT")
+
+  # Check if the RC already exists, and if re-creating the RC, skip tag creation.
+  RELEASE_TAG="v${RELEASE_VERSION}-rc${RC_COUNT}"
+  SKIP_TAG=0
+  if check_for_tag "RELEASE_TAG"; then
+    read -p "$RELEASE_TAG already exists. Continue anyway [y/n]? " ANSWER
+    if [ "$ANSWER" != "y" ]; then
+      error "Exiting."
+    fi
+    SKIP_TAG=1
+  fi
+
+  export RELEASE_TAG
+  export GIT_REF="$RELEASE_TAG"
+  export SPARK_PACKAGE_VERSION="$RELEASE_TAG"
+
+  # Gather some user information.
+  export ASF_USERNAME=$(read_config "ASF user" "$LOGNAME")
+
+  GIT_NAME=$(git config user.name)
+  export GIT_NAME=$(read_config "Full name" "$GIT_NAME")
+
+  export GIT_EMAIL="$ASF_USERNAME@apache.org"
+  export GPG_KEY=$(read_config "GPG key" "$GIT_EMAIL")
+
+  cat <<EOF
+================
+Release details:
+BRANCH:     $GIT_BRANCH
+VERSION:    $RELEASE_VERSION
+TAG:        $RELEASE_TAG
+NEXT:       $NEXT_VERSION
+
+ASF USER:   $ASF_USERNAME
+GPG KEY:    $GPG_KEY
+FULL NAME:  $GIT_NAME
+E-MAIL:     $GIT_EMAIL
+================
+EOF
+
+  read -p "Is this info correct [y/n]? " ANSWER
+  if [ "$ANSWER" != "y" ]; then
+    echo "Exiting."
+    exit 1
+  fi
+
+  if [ -z "$ASF_PASSWORD" ]; then
+    stty -echo && printf "ASF password: " && read ASF_PASSWORD && printf '\n' && stty echo
+    export ASF_PASSWORD
+  fi
+
+  if [ -z "$GPG_PASSPHRASE" ]; then
+    stty -echo && printf "GPG passphrase: " && read GPG_PASSPHRASE && printf '\n' && stty echo
+    export GPG_PASSPHRASE
+  fi
+}