pull response a little weird

[jimfulton]

pull returns a string that's a contamination of one or more JSON strings.

Wouldn't it make more sense to return either that last status as a dict, or a list of status dicts?

[jimfulton]

Or it might make sense not to return anything and error if you get a 404. Or return the fetched image id and error on 404.

It turns out I'm not using the output of pull, but calling images to get the image id for the pulled image, so I can detect a failure if the pulled image isn't returned from images.

[mpetazzoni]

When you set stream=True this output makes a lot more sense. But I agree that if you don't care about the real-time progress then we can probably "summarize" it into a more useful result data structure before returning. Would you be interested in taking a crack at it?

[jimfulton]

Sure.

[vmalloc]

+1

stream=True only makes partial sense IMO, because waiting too long before polling the generator once again concatenates strings:

>>> c = docker.Client()
>>> gen = c.pull("ubuntu", tag="latest", stream=True)
>>> time.sleep(60)
>>> next(gen)
'{"status":"Pulling image (latest) from ubuntu","progressDetail":{},"id":"ad892dd21d60"}{"status":"Pulling image (latest) from ubuntu, endpoint: https://cdn-registry-1.docker.io/v1/","progressDetail":{},"id":"ad892dd21d60"}{"status":"Pulling dependent layers","progressDetail":{},"id":"ad892dd21d60"}{"status":"Download complete","progressDetail":{},"id":"511136ea3c5a"}{"status":"Download complete","progressDetail":{},"id":"e465fff03bce"}{"status":"Download complete","progressDetail":{},"id":"23f361102fae"}{"status":"Download complete","progressDetail":{},"id":"9db365ecbcbb"}{"status":"Download complete","progressDetail":{},"id":"ad892dd21d60"}{"status":"Download complete","progressDetail":{},"id":"ad892dd21d60"}'

[bfirsh]

Compose's json_stream helper is now included in the development version which will help enormously with this. See here for an example of an implementation with build:

docker-py/docker/models/images.py

Lines 96 to 169 in 1984f68

	def build(self, **kwargs):
	"""
	Build an image and return it. Similar to the ``docker build``
	command. Either ``path`` or ``fileobj`` must be set.
	If you have a tar file for the Docker build context (including a
	Dockerfile) already, pass a readable file-like object to ``fileobj``
	and also pass ``custom_context=True``. If the stream is compressed
	also, set ``encoding`` to the correct value (e.g ``gzip``).
	If you want to get the raw output of the build, use the
	:py:meth:`~docker.api.build.BuildApiMixin.build` method in the
	low-level API.
	Args:
	path (str): Path to the directory containing the Dockerfile
	fileobj: A file object to use as the Dockerfile. (Or a file-like
	object)
	tag (str): A tag to add to the final image
	quiet (bool): Whether to return the status
	nocache (bool): Don't use the cache when set to ``True``
	rm (bool): Remove intermediate containers. The ``docker build``
	command now defaults to ``--rm=true``, but we have kept the old
	default of `False` to preserve backward compatibility
	stream (bool): *Deprecated for API version > 1.8 (always True)*.
	Return a blocking generator you can iterate over to retrieve
	build output as it happens
	timeout (int): HTTP timeout
	custom_context (bool): Optional if using ``fileobj``
	encoding (str): The encoding for a stream. Set to ``gzip`` for
	compressing
	pull (bool): Downloads any updates to the FROM image in Dockerfiles
	forcerm (bool): Always remove intermediate containers, even after
	unsuccessful builds
	dockerfile (str): path within the build context to the Dockerfile
	buildargs (dict): A dictionary of build arguments
	container_limits (dict): A dictionary of limits applied to each
	container created by the build process. Valid keys:
	- memory (int): set memory limit for build
	- memswap (int): Total memory (memory + swap), -1 to disable
	swap
	- cpushares (int): CPU shares (relative weight)
	- cpusetcpus (str): CPUs in which to allow execution, e.g.,
	``"0-3"``, ``"0,1"``
	decode (bool): If set to ``True``, the returned stream will be
	decoded into dicts on the fly. Default ``False``.
	Returns:
	(:py:class:`Image`): The built image.
	Raises:
	:py:class:`docker.errors.BuildError`
	If there is an error during the build.
	:py:class:`docker.errors.APIError`
	If the server returns any other error.
	``TypeError``
	If neither ``path`` nor ``fileobj`` is specified.
	"""
	resp = self.client.api.build(**kwargs)
	if isinstance(resp, six.string_types):
	return self.get(resp)
	events = list(json_stream(resp))
	if not events:
	return BuildError('Unknown')
	event = events[-1]
	if 'stream' in event:
	match = re.search(r'Successfully built ([0-9a-f]+)',
	event.get('stream', ''))
	if match:
	image_id = match.group(1)
	return self.get(image_id)
	raise BuildError(event.get('error') or event)