tools/build_defs/docker/create_image.py - bazel - Git at Google

 # 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.
 """This tool creates a docker image from a layer and the various metadata."""

 import json
 import re
 import sys
 import tarfile

 from tools.build_defs.docker import utils
 from tools.build_defs.pkg import archive
 from third_party.py import gflags

 # Hardcoded docker versions that we are claiming to be.
 DATA_FORMAT_VERSION = '1.0'

 gflags.DEFINE_string(
     'output', None,
     'The output file, mandatory')
 gflags.MarkFlagAsRequired('output')

 gflags.DEFINE_multistring(
     'layer', [],
     'Layer tar files and their identifiers that make up this image')

 gflags.DEFINE_string(
     'id', None,
     'The hex identifier of this image (hexstring or @filename), mandatory.')
 gflags.MarkFlagAsRequired('id')

 gflags.DEFINE_string('config', None,
                      'The JSON configuration file for this image, mandatory.')
 gflags.MarkFlagAsRequired('config')

 gflags.DEFINE_string('base', None, 'The base image file for this image.')

 gflags.DEFINE_string(
     'legacy_id', None,
     'The legacy hex identifier of this layer (hexstring or @filename).')

 gflags.DEFINE_string('metadata', None,
                      'The legacy JSON metadata file for this layer.')

 gflags.DEFINE_string('legacy_base', None,
                      'The legacy base image file for this image.')

 gflags.DEFINE_string(
     'repository', None,
     'The name of the repository to add this image.')

 gflags.DEFINE_string(
     'name', None,
     'The symbolic name of this image.')

 gflags.DEFINE_multistring('tag', None,
                           'The repository tags to apply to the image')

 FLAGS = gflags.FLAGS


 def _base_name_filter(name):
   """Do not add multiple times 'top' and 'repositories' when merging images."""
   filter_names = ['top', 'repositories', 'manifest.json']
   return all([not name.endswith(s) for s in filter_names])


 def create_image(output,
                  identifier,
                  layers,
                  config,
                  tags=None,
                  base=None,
                  legacy_base=None,
                  metadata_id=None,
                  metadata=None,
                  name=None,
                  repository=None):
   """Creates a Docker image.

   Args:
     output: the name of the docker image file to create.
     identifier: the identifier for this image (sha256 of the metadata).
     layers: the layer content (a sha256 and a tar file).
     config: the configuration file for the image.
     tags: tags that apply to this image.
     base: a base layer (optional) to build on top of.
     legacy_base: a base layer (optional) to build on top of.
     metadata_id: the identifier of the top layer for this image.
     metadata: the json metadata file for the top layer.
     name: symbolic name for this docker image.
     repository: repository name for this docker image.
   """
   tar = archive.TarFileWriter(output)

   # add the image config referenced by the Config section in the manifest
   # the name can be anything but docker uses the format below
   config_file_name = identifier + '.json'
   tar.add_file(config_file_name, file_content=config)

   layer_file_names = []

   if metadata_id:
     # Write our id to 'top' as we are now the topmost layer.
     tar.add_file('top', content=metadata_id)

     # Each layer is encoded as a directory in the larger tarball of the form:
     #  {id}\
     #    layer.tar
     #    VERSION
     #    json
     # Create the directory for us to now fill in.
     tar.add_file(metadata_id + '/', tarfile.DIRTYPE)
     # VERSION generally seems to contain 1.0, not entirely sure
     # what the point of this is.
     tar.add_file(metadata_id + '/VERSION', content=DATA_FORMAT_VERSION)
     # Add the layer file
     layer_file_name = metadata_id + '/layer.tar'
     layer_file_names.append(layer_file_name)
     tar.add_file(layer_file_name, file_content=layers[0]['layer'])
     # Now the json metadata
     tar.add_file(metadata_id + '/json', file_content=metadata)

     # Merge the base if any
     if legacy_base:
       tar.add_tar(legacy_base, name_filter=_base_name_filter)
   else:
     for layer in layers:
       # layers can be called anything, so just name them by their sha256
       layer_file_name = identifier + '/' + layer['name'] + '.tar'
       layer_file_names.append(layer_file_name)
       tar.add_file(layer_file_name, file_content=layer['layer'])

   base_layer_file_names = []
   parent = None
   if base:
     latest_item = utils.GetLatestManifestFromTar(base)
     if latest_item:
       base_layer_file_names = latest_item.get('Layers', [])
       config_file = latest_item['Config']
       parent_search = re.search('^(.+)\\.json$', config_file)
       if parent_search:
         parent = parent_search.group(1)

   manifest_item = {
       'Config': config_file_name,
       'Layers': base_layer_file_names + layer_file_names,
       'RepoTags': tags or []
   }
   if parent:
     manifest_item['Parent'] = 'sha256:' + parent

   manifest = [manifest_item]

   manifest_content = json.dumps(manifest, sort_keys=True)
   tar.add_file('manifest.json', content=manifest_content)

   # In addition to N layers of the form described above, there is
   # a single file at the top of the image called repositories.
   # This file contains a JSON blob of the form:
   # {
   #   'repo':{
   #     'tag-name': 'top-most layer hex',
   #     ...
   #   },
   #   ...
   # }
   if repository:
     tar.add_file('repositories', content='\n'.join([
         '{',
         '  "%s": {' % repository,
         '    "%s": "%s"' % (name, identifier),
         '  }',
         '}']))


 # Main program to create a docker image. It expect to be run with:
 # create_image --output=output_file \
 #              --id=@identifier \
 #              [--base=base] \
 #              --layer=@identifier=layer.tar \
 #              --metadata=metadata.json \
 #              --name=myname --repository=repositoryName \
 #              --tag=repo/image:tag
 # See the gflags declaration about the flags argument details.
 def main(unused_argv):
   identifier = utils.ExtractValue(FLAGS.id)
   legacy_id = utils.ExtractValue(FLAGS.legacy_id)

   layers = []
   for kv in FLAGS.layer:
     (k, v) = kv.split('=', 1)
     layers.append({
         'name': utils.ExtractValue(k),
         'layer': v,
     })

   create_image(FLAGS.output, identifier, layers, FLAGS.config, FLAGS.tag,
                FLAGS.base, FLAGS.legacy_base, legacy_id, FLAGS.metadata,
                FLAGS.name, FLAGS.repository)

 if __name__ == '__main__':
   main(FLAGS(sys.argv))
	# 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.
	"""This tool creates a docker image from a layer and the various metadata."""

	import json
	import re
	import sys
	import tarfile

	from tools.build_defs.docker import utils
	from tools.build_defs.pkg import archive
	from third_party.py import gflags

	# Hardcoded docker versions that we are claiming to be.
	DATA_FORMAT_VERSION = '1.0'

	gflags.DEFINE_string(
	'output', None,
	'The output file, mandatory')
	gflags.MarkFlagAsRequired('output')

	gflags.DEFINE_multistring(
	'layer', [],
	'Layer tar files and their identifiers that make up this image')

	gflags.DEFINE_string(
	'id', None,
	'The hex identifier of this image (hexstring or @filename), mandatory.')
	gflags.MarkFlagAsRequired('id')

	gflags.DEFINE_string('config', None,
	'The JSON configuration file for this image, mandatory.')
	gflags.MarkFlagAsRequired('config')

	gflags.DEFINE_string('base', None, 'The base image file for this image.')

	gflags.DEFINE_string(
	'legacy_id', None,
	'The legacy hex identifier of this layer (hexstring or @filename).')

	gflags.DEFINE_string('metadata', None,
	'The legacy JSON metadata file for this layer.')

	gflags.DEFINE_string('legacy_base', None,
	'The legacy base image file for this image.')

	gflags.DEFINE_string(
	'repository', None,
	'The name of the repository to add this image.')

	gflags.DEFINE_string(
	'name', None,
	'The symbolic name of this image.')

	gflags.DEFINE_multistring('tag', None,
	'The repository tags to apply to the image')

	FLAGS = gflags.FLAGS


	def _base_name_filter(name):
	"""Do not add multiple times 'top' and 'repositories' when merging images."""
	filter_names = ['top', 'repositories', 'manifest.json']
	return all([not name.endswith(s) for s in filter_names])


	def create_image(output,
	identifier,
	layers,
	config,
	tags=None,
	base=None,
	legacy_base=None,
	metadata_id=None,
	metadata=None,
	name=None,
	repository=None):
	"""Creates a Docker image.

	Args:
	output: the name of the docker image file to create.
	identifier: the identifier for this image (sha256 of the metadata).
	layers: the layer content (a sha256 and a tar file).
	config: the configuration file for the image.
	tags: tags that apply to this image.
	base: a base layer (optional) to build on top of.
	legacy_base: a base layer (optional) to build on top of.
	metadata_id: the identifier of the top layer for this image.
	metadata: the json metadata file for the top layer.
	name: symbolic name for this docker image.
	repository: repository name for this docker image.
	"""
	tar = archive.TarFileWriter(output)

	# add the image config referenced by the Config section in the manifest
	# the name can be anything but docker uses the format below
	config_file_name = identifier + '.json'
	tar.add_file(config_file_name, file_content=config)

	layer_file_names = []

	if metadata_id:
	# Write our id to 'top' as we are now the topmost layer.
	tar.add_file('top', content=metadata_id)

	# Each layer is encoded as a directory in the larger tarball of the form:
	# {id}\
	# layer.tar
	# VERSION
	# json
	# Create the directory for us to now fill in.
	tar.add_file(metadata_id + '/', tarfile.DIRTYPE)
	# VERSION generally seems to contain 1.0, not entirely sure
	# what the point of this is.
	tar.add_file(metadata_id + '/VERSION', content=DATA_FORMAT_VERSION)
	# Add the layer file
	layer_file_name = metadata_id + '/layer.tar'
	layer_file_names.append(layer_file_name)
	tar.add_file(layer_file_name, file_content=layers[0]['layer'])
	# Now the json metadata
	tar.add_file(metadata_id + '/json', file_content=metadata)

	# Merge the base if any
	if legacy_base:
	tar.add_tar(legacy_base, name_filter=_base_name_filter)
	else:
	for layer in layers:
	# layers can be called anything, so just name them by their sha256
	layer_file_name = identifier + '/' + layer['name'] + '.tar'
	layer_file_names.append(layer_file_name)
	tar.add_file(layer_file_name, file_content=layer['layer'])

	base_layer_file_names = []
	parent = None
	if base:
	latest_item = utils.GetLatestManifestFromTar(base)
	if latest_item:
	base_layer_file_names = latest_item.get('Layers', [])
	config_file = latest_item['Config']
	parent_search = re.search('^(.+)\\.json$', config_file)
	if parent_search:
	parent = parent_search.group(1)

	manifest_item = {
	'Config': config_file_name,
	'Layers': base_layer_file_names + layer_file_names,
	'RepoTags': tags or []
	}
	if parent:
	manifest_item['Parent'] = 'sha256:' + parent

	manifest = [manifest_item]

	manifest_content = json.dumps(manifest, sort_keys=True)
	tar.add_file('manifest.json', content=manifest_content)

	# In addition to N layers of the form described above, there is
	# a single file at the top of the image called repositories.
	# This file contains a JSON blob of the form:
	# {
	# 'repo':{
	# 'tag-name': 'top-most layer hex',
	# ...
	# },
	# ...
	# }
	if repository:
	tar.add_file('repositories', content='\n'.join([
	'{',
	' "%s": {' % repository,
	' "%s": "%s"' % (name, identifier),
	' }',
	'}']))


	# Main program to create a docker image. It expect to be run with:
	# create_image --output=output_file \
	# --id=@identifier \
	# [--base=base] \
	# --layer=@identifier=layer.tar \
	# --metadata=metadata.json \
	# --name=myname --repository=repositoryName \
	# --tag=repo/image:tag
	# See the gflags declaration about the flags argument details.
	def main(unused_argv):
	identifier = utils.ExtractValue(FLAGS.id)
	legacy_id = utils.ExtractValue(FLAGS.legacy_id)

	layers = []
	for kv in FLAGS.layer:
	(k, v) = kv.split('=', 1)
	layers.append({
	'name': utils.ExtractValue(k),
	'layer': v,
	})

	create_image(FLAGS.output, identifier, layers, FLAGS.config, FLAGS.tag,
	FLAGS.base, FLAGS.legacy_base, legacy_id, FLAGS.metadata,
	FLAGS.name, FLAGS.repository)

	if __name__ == '__main__':
	main(FLAGS(sys.argv))