def multi_image_tarball(tag_to_image, tar, tag_to_v1_image=None):
"""Produce a "docker save" compatible tarball from the DockerImages.
Args:
tag_to_image: A dictionary of tags to the images they label.
tar: the open tarfile into which we are writing the image tarball.
tag_to_v1_image: A dictionary of tags to the v1 form of the images
they label. If this isn't provided, the image is simply converted.
"""
def add_file(filename, contents):
info = tarfile.TarInfo(filename)
info.size = len(contents)
tar.addfile(tarinfo=info, fileobj=io.BytesIO(contents))
tag_to_v1_image = tag_to_v1_image or {}
# The manifest.json file contains a list of the images to load
# and how to tag them. Each entry consists of three fields:
# - Config: the name of the image's config_file() within the
# saved tarball.
# - Layers: the list of filenames for the blobs constituting
# this image. The order is the reverse of the v1
# ancestry ordering.
# - RepoTags: the list of tags to apply to this image once it
# is loaded.
manifests = []
for (tag, image) in six.iteritems(tag_to_image):
# The config file is stored in a blob file named with its digest.
digest = hashlib.sha256(image.config_file()).hexdigest()
add_file(digest + '.json', image.config_file())
cfg = json.loads(image.config_file())
diffs = set(cfg.get('rootfs', {}).get('diff_ids', []))
v1_img = tag_to_v1_image.get(tag)
if not v1_img:
v2_img = v2_compat.V2FromV22(image)
v1_img = v1_compat.V1FromV2(v2_img)
tag_to_v1_image[tag] = v1_img
# Add the manifests entry for this image.
manifests.append({
'Config':
digest + '.json',
'Layers': [
layer_id + '/layer.tar'
# We don't just exclude the empty tar because we leave its diff_id
# in the set when coming through v2_compat.V22FromV2
for layer_id in reversed(v1_img.ancestry(v1_img.top()))
if _diff_id(v1_img, layer_id) in diffs
],
'RepoTags': [str(tag)]
})
# v2.2 tarballs are a superset of v1 tarballs, so delegate
# to v1 to save itself.
v1_save.multi_image_tarball(tag_to_v1_image, tar)
add_file('manifest.json', json.dumps(manifests, sort_keys=True))
def multi_image_tarball(
tag_to_image,
tar,
tag_to_v1_image = None
):
"""Produce a "docker save" compatible tarball from the DockerImages.
Args:
tag_to_image: A dictionary of tags to the images they label.
tar: the open tarfile into which we are writing the image tarball.
tag_to_v1_image: A dictionary of tags to the v1 form of the images
they label. If this isn't provided, the image is simply converted.
"""
def add_file(filename, contents):
contents_bytes = contents.encode('utf8')
info = tarfile.TarInfo(filename)
info.size = len(contents_bytes)
tar.addfile(tarinfo=info, fileobj=io.BytesIO(contents_bytes))
tag_to_v1_image = tag_to_v1_image or {}
# The manifest.json file contains a list of the images to load
# and how to tag them. Each entry consists of three fields:
# - Config: the name of the image's config_file() within the
# saved tarball.
# - Layers: the list of filenames for the blobs constituting
# this image. The order is the reverse of the v1
# ancestry ordering.
# - RepoTags: the list of tags to apply to this image once it
# is loaded.
manifests = []
for (tag, image) in six.iteritems(tag_to_image):
# The config file is stored in a blob file named with its digest.
digest = docker_digest.SHA256(image.config_file().encode('utf8'), '')
add_file(digest + '.json', image.config_file())
cfg = json.loads(image.config_file())
diffs = set(cfg.get('rootfs', {}).get('diff_ids', []))
v1_img = tag_to_v1_image.get(tag)
if not v1_img:
v2_img = v2_compat.V2FromV22(image)
v1_img = v1_compat.V1FromV2(v2_img)
tag_to_v1_image[tag] = v1_img
# Add the manifests entry for this image.
manifests.append({
'Config':
digest + '.json',
'Layers': [
layer_id + '/layer.tar'
# We don't just exclude the empty tar because we leave its diff_id
# in the set when coming through v2_compat.V22FromV2
for layer_id in reversed(v1_img.ancestry(v1_img.top()))
if _diff_id(v1_img, layer_id) in diffs
],
'RepoTags': [str(tag)]
})
# v2.2 tarballs are a superset of v1 tarballs, so delegate
# to v1 to save itself.
v1_save.multi_image_tarball(tag_to_v1_image, tar)
add_file('manifest.json', json.dumps(manifests, sort_keys=True))