bazel

#!/bin/bash
#
# Copyright 2016 The Minimal Configuration Manager 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.

# Wrapper that autoinstalls Bazel

die() {
  echo "$@" 1>&2
  exit 1
}

WORKSPACE_DIR="$(cd "$(dirname "$0")" && pwd -P)"
BAZEL_RELEASE='0.4.4'

check-bazel-version() {
  "$1" version | grep "^Build label: $BAZEL_RELEASE\$" > /dev/null 2>&1
}

# Check if Bazel in PATH is correct version
if hash bazel > /dev/null 2>&1 && check-bazel-version bazel; then
  exec bazel "$@"
fi

# Check if existing workspace Bazel is correct version
if [[ -x "$WORKSPACE_DIR/.bazel/bin/bazel" ]] && \
    check-bazel-version "$WORKSPACE_DIR/.bazel/bin/bazel"; then
  exec "$WORKSPACE_DIR/.bazel/bin/bazel" "$@"
fi

# Download correct Bazel release to workspace
rm -rf "$WORKSPACE_DIR/.bazel"
echo "Downloading Bazel ${BAZEL_RELEASE}..." 1>&2
case "$(uname -s)" in
  Linux)
    platform="linux-$(uname -m)"
    ;;
  Darwin)
    platform="darwin-$(uname -m)"
    ;;
  *)
    die "unknown OS $(uname -s)"
    ;;
esac
installscript="/tmp/bazel-${BAZEL_RELEASE}.sh"
curl -sSL "https://github.com/bazelbuild/bazel/releases/download/${BAZEL_RELEASE}/bazel-${BAZEL_RELEASE}-installer-${platform}.sh" > "$installscript" || \
  (rm -f "$installscript" ; die "bazel: wrapper: failed to download")
bash /tmp/bazel-${BAZEL_RELEASE}.sh \
  --bin="$WORKSPACE_DIR/.bazel/bin" \
  --base="$WORKSPACE_DIR/.bazel/lib" \
  --bazelrc="$WORKSPACE_DIR/.bazel/bazelrc" || \
  (rm -f "$installscript" ; die "bazel: wrapper: failed to install")
rm -f "$installscript"
exec "$WORKSPACE_DIR/.bazel/bin/bazel" "$@"