def load_image(url, imageName=None, imageTag=None):
"""
Load docker image from URL as imageName:tag, if no imageName or tag is given
it will use whatever is inside the zstd compressed tarball.
Returns an object with properties 'image', 'tag' and 'layer'.
"""
# If imageName is given and we don't have an imageTag
# we parse out the imageTag from imageName, or default it to 'latest'
# if no imageName and no imageTag is given, 'repositories' won't be rewritten
if imageName and not imageTag:
if ':' in imageName:
imageName, imageTag = imageName.split(':', 1)
else:
imageTag = 'latest'
curl, zstd, docker = None, None, None
image, tag, layer = None, None, None
error = None
try:
# Setup piping: curl | zstd | tarin
curl = Popen(['curl', '-#', '--fail', '-L', '--retry', '8', url], stdout=PIPE)
zstd = Popen(['zstd', '-d'], stdin=curl.stdout, stdout=PIPE)
tarin = tarfile.open(mode='r|', fileobj=zstd.stdout)
# Seutp piping: tarout | docker
docker = Popen(['docker', 'load'], stdin=PIPE)
tarout = tarfile.open(mode='w|', fileobj=docker.stdin, format=tarfile.GNU_FORMAT)
# Read from tarin and write to tarout
for member in tarin:
# Write non-file members directly (don't use extractfile on links)
if not member.isfile():
tarout.addfile(member)
continue
# Open reader for the member
reader = tarin.extractfile(member)
# If member is repository, we parse and possibly rewrite the image tags
if member.name == 'repositories':
# Read and parse repositories
repos = json.loads(reader.read())
reader.close()
# If there is more than one image or tag, we can't handle it here
if len(repos.keys()) > 1:
raise Exception('file contains more than one image')
image = repos.keys()[0]
if len(repos[image].keys()) > 1:
raise Exception('file contains more than one tag')
tag = repos[image].keys()[0]
layer = repos[image][tag]
# Rewrite the repositories file
data = json.dumps({imageName or image: {imageTag or tag: layer}})
reader = BytesIO(data)
member.size = len(data)
# Add member and reader
tarout.addfile(member, reader)
reader.close()
tarout.close()
except Exception:
error = sys.exc_info()[0]
finally:
def trykill(proc):
try:
proc.kill()
except:
pass
# Check that all subprocesses finished correctly
if curl and curl.wait() != 0:
trykill(zstd)
trykill(docker)
raise Exception('failed to download from url: {}'.format(url))
if zstd and zstd.wait() != 0:
trykill(docker)
raise Exception('zstd decompression failed')
if docker:
docker.stdin.close()
if docker and docker.wait() != 0:
raise Exception('loading into docker failed')
if error:
raise error
# Check that we found a repositories file
if not image or not tag or not layer:
raise Exception('No repositories file found!')
return {'image': image, 'tag': tag, 'layer': layer}
def load_image(url, imageName=None, imageTag=None):
"""
Load docker image from URL as imageName:tag, if no imageName or tag is given
it will use whatever is inside the zstd compressed tarball.
Returns an object with properties 'image', 'tag' and 'layer'.
"""
# If imageName is given and we don't have an imageTag
# we parse out the imageTag from imageName, or default it to 'latest'
# if no imageName and no imageTag is given, 'repositories' won't be rewritten
if imageName and not imageTag:
if ':' in imageName:
imageName, imageTag = imageName.split(':', 1)
else:
imageTag = 'latest'
curl, zstd, docker = None, None, None
image, tag, layer = None, None, None
error = None
try:
# Setup piping: curl | zstd | tarin
curl = Popen(['curl', '-#', '--fail', '-L', '--retry', '8', url], stdout=PIPE)
zstd = Popen(['zstd', '-d'], stdin=curl.stdout, stdout=PIPE)
tarin = tarfile.open(mode='r|', fileobj=zstd.stdout)
# Seutp piping: tarout | docker
docker = Popen(['docker', 'load'], stdin=PIPE)
tarout = tarfile.open(mode='w|', fileobj=docker.stdin, format=tarfile.GNU_FORMAT)
# Read from tarin and write to tarout
for member in tarin:
# Write non-file members directly (don't use extractfile on links)
if not member.isfile():
tarout.addfile(member)
continue
# Open reader for the member
reader = tarin.extractfile(member)
# If member is repository, we parse and possibly rewrite the image tags
if member.name == 'repositories':
# Read and parse repositories
repos = json.loads(reader.read())
reader.close()
# If there is more than one image or tag, we can't handle it here
if len(repos.keys()) > 1:
raise Exception('file contains more than one image')
image = repos.keys()[0]
if len(repos[image].keys()) > 1:
raise Exception('file contains more than one tag')
tag = repos[image].keys()[0]
layer = repos[image][tag]
# Rewrite the repositories file
data = json.dumps({imageName or image: {imageTag or tag: layer}})
reader = BytesIO(data)
member.size = len(data)
# Add member and reader
tarout.addfile(member, reader)
reader.close()
tarout.close()
except Exception:
error = sys.exc_info()[0]
finally:
def trykill(proc):
try:
proc.kill()
except:
pass
# Check that all subprocesses finished correctly
if curl and curl.wait() != 0:
trykill(zstd)
trykill(docker)
raise Exception('failed to download from url: {}'.format(url))
if zstd and zstd.wait() != 0:
trykill(docker)
raise Exception('zstd decompression failed')
if docker:
docker.stdin.close()
if docker and docker.wait() != 0:
raise Exception('loading into docker failed')
if error:
raise error
# Check that we found a repositories file
if not image or not tag or not layer:
raise Exception('No repositories file found!')
return {'image': image, 'tag': tag, 'layer': layer}