tools/build_defs/docker/incremental_load.sh.tpl

#!/bin/bash
#
# Copyright 2015 The Bazel Authors. 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.

set -eu

# This is a generated file that loads all docker layers built by "docker_build".

RUNFILES="${PYTHON_RUNFILES:-${BASH_SOURCE[0]}.runfiles}"

DOCKER="${DOCKER:-docker}"

FULL_DOCKER_VERSION=$(docker version -f {{.Server.Version}} 2> /dev/null \
    || echo "1.5.0")
DOCKER_MAJOR_VERSION=$(echo "$FULL_DOCKER_VERSION" | awk -F\. '{ print $1 }')
DOCKER_MINOR_VERSION=$(echo "$FULL_DOCKER_VERSION" | awk -F\. '{ print $2 }')
if [ "$DOCKER_MAJOR_VERSION" -eq "1" ] && [ "$DOCKER_MINOR_VERSION" -lt "10" ]; then
  LEGACY_DOCKER=true
else
  LEGACY_DOCKER=false
fi

# List all images identifier (only the identifier) from the local
# docker registry.
IMAGES="$("${DOCKER}" images -aq)"
IMAGE_LEN=$(for i in $IMAGES; do echo -n $i | wc -c; done | sort -g | head -1 | xargs)

[ -n "$IMAGE_LEN" ] || IMAGE_LEN=64

function incr_load() {
  # Load a layer if and only if the layer is not in "$IMAGES", that is
  # in the local docker registry.
  if [ "$LEGACY_DOCKER" = true ]; then
    name=$(cat ${RUNFILES}/$1)
  else
    name=$(cat ${RUNFILES}/$2)
  fi

  if (echo "$IMAGES" | grep -q ^${name:0:$IMAGE_LEN}$); then
    echo "Skipping $name, already loaded."
  else
    echo "Loading $name..."
    "${DOCKER}" load -i ${RUNFILES}/$3
  fi
}

# List of 'incr_load' statements for all layers.
# This generated and injected by docker_build.
%{load_statements}

# Tag the last layer.
if [ -n "${name}" ]; then
  TAG="${1:-%{repository}:%{tag}}"
  echo "Tagging ${name} as ${TAG}"
  if [ "$LEGACY_DOCKER" = true ]; then
    "${DOCKER}" tag -f ${name} ${TAG}
  else
    "${DOCKER}" tag ${name} ${TAG}
  fi
fi