def __init__(self, base, tar_gz,
port, *envs):
"""Creates a new layer on top of a base with optional tar.gz, port or envs.
Args:
base: a base DockerImage for a new layer.
tar_gz: an optional gzipped tarball passed as a string with filesystem
changeset.
port: an optional port to be exposed, passed as a string. For example:
'8080/tcp'.
*envs: environment variables passed as strings in the format:
'ENV_ONE=val', 'ENV_TWO=val2'.
"""
self._base = base
unsigned_manifest, unused_signatures = util.DetachSignatures(
self._base.manifest())
manifest = json.loads(unsigned_manifest)
v1_compat = json.loads(manifest['history'][0]['v1Compatibility'])
if tar_gz:
if isinstance(tar_gz, six.text_type):
self._blob = tar_gz.encode()
else:
self._blob = tar_gz
self._blob_sum = 'sha256:' + hashlib.sha256(self._blob).hexdigest()
v1_compat['throwaway'] = False
else:
self._blob_sum = _EMPTY_LAYER_TAR_ID
self._blob = ''
v1_compat['throwaway'] = True
manifest['fsLayers'].insert(0, {'blobSum': self._blob_sum})
v1_compat['parent'] = v1_compat['id']
v1_compat['id'] = binascii.hexlify(os.urandom(32)).decode('ascii')
config = v1_compat.get('config', {}) or {}
envs = list(envs)
if envs:
env_keys = [env.split('=')[0] for env in envs]
old_envs = config.get('Env', []) or []
old_envs = [env for env in old_envs if env.split('=')[0] not in env_keys]
config['Env'] = old_envs + envs
if port is not None:
old_ports = config.get('ExposedPorts', {}) or {}
old_ports[port] = {}
config['ExposedPorts'] = old_ports
v1_compat['config'] = config
manifest['history'].insert(
0, {'v1Compatibility': json.dumps(v1_compat, sort_keys=True)})
self._manifest = util.Sign(json.dumps(manifest, sort_keys=True))
def SignedManifestToSHA256(manifest):
"""Return 'sha256:' + hex(sha256(manifest - signatures))."""
unsigned_manifest, unused_signatures = util.DetachSignatures(manifest)
return SHA256(unsigned_manifest.encode('utf8'))