Docker Image

Aside from methods in API definition - conu.apidefs.image.Image, DockerImage implements following methods:

class conu.DockerImage(repository, tag=u'latest', pull_policy=<DockerImagePullPolicy.IF_NOT_PRESENT: 1>)

Utility functions for docker images.

These methods are specific to this backend:

These generic methods are not implemented in this backend:

__init__(repository, tag=u'latest', pull_policy=<DockerImagePullPolicy.IF_NOT_PRESENT: 1>)
Parameters:
  • repository – str, image name, examples: “fedora”, “registry.fedoraproject.org/fedora”, “tomastomecek/sen”, “docker.io/tomastomecek/sen”
  • tag – str, tag of the image, when not specified, “latest” is implied
  • pull_policy – enum, strategy to apply for pulling the image
get_full_name()

Provide full, complete image name

Returns:str
get_id()

get unique identifier of this image

Returns:str
get_metadata(refresh=True)

return cached metadata by default

Parameters:refresh – bool, update the metadata with up to date content
Returns:dict
inspect(refresh=True)

return cached metadata by default (a convenience method)

Parameters:refresh – bool, update the metadata with up to date content
Returns:dict
is_present()

Is this docker image present locally on the system?

Returns:bool, True if it is, False if it’s not
mount(mount_point=None)

mount image filesystem

Parameters:mount_point – str, directory where the filesystem will be mounted
Returns:instance of DockerImageFS
pull()

Pull this image from registry. Raises an exception if the image is not found in the registry.

Returns:None
rmi(force=False, via_name=False)

remove this image

Parameters:
  • force – bool, force removal of the image
  • via_name – bool, refer to the image via name, if false, refer via ID
Returns:

None
run_via_binary(run_command_instance=None, *args, **kwargs)

create a container using this image and run it in background; this method is useful to test real user scenarios when users invoke containers using binary

Parameters:run_command_instance – instance of DockerRunBuilder
Returns:instance of DockerContainer
run_via_binary_in_foreground(run_command_instance=None, popen_params=None, container_name=None)

Create a container using this image and run it in foreground; this method is useful to test real user scenarios when users invoke containers using binary and pass input into the container via STDIN. You are also responsible for:

  • redirecting STDIN when intending to use container.write_to_stdin afterwards by setting
    popen_params={“stdin”: subprocess.PIPE} during run_via_binary_in_foreground
  • checking whether the container exited successfully via:
    container.popen_instance.returncode

Please consult the documentation for subprocess python module for best practices on how you should work with instance of Popen

Parameters:
  • run_command_instance – instance of DockerRunBuilder
  • popen_params – dict, keyword arguments passed to Popen constructor
  • container_name – str, pretty container identifier
Returns:

instance of DockerContainer
tag_image(repository=None, tag=None)

Apply additional tags to the image or even add a new name

Parameters:
  • repository – str, see constructor
  • tag – str, see constructor
Returns:

instance of DockerImage
class conu.DockerImagePullPolicy

This Enum defines the policy for pulling the docker images. The pull operation happens when creating an instance of a docker image. Supported values:

  • NEVER - do not pull the image
  • IF_NOT_PRESENT - pull it only if the image is not present
  • ALWAYS - always initiate the pull process - the image is being pulled even if it’s present locally. It means that it may be overwritten by a remote counterpart or there may be a exception being raised if no such image is present in the registry.
class conu.DockerImageFS(image, mount_point=None)

These generic methods are not implemented in this backend:

__init__(image, mount_point=None)

Raises CommandDoesNotExistException if the command is not present on the system.

Parameters:
  • image – instance of DockerImage
  • mount_point – str, directory where the filesystem will be mounted

Aside from methods in API definition - conu.apidefs.image.S2Image, S2IDockerImage implements following methods:

class conu.S2IDockerImage(repository, tag=u'latest')

These methods are specific to this backend:

These generic methods are not implemented in this backend:

extend(source, new_image_name, s2i_args=None)

extend this s2i-enabled image using provided source, raises ConuException if s2i build fails

Parameters:
  • source – str, source used to extend the image, can be path or url
  • new_image_name – str, name of the new, extended image
  • s2i_args – list of str, additional options and arguments provided to s2i build
Returns:

S2Image instance
usage()

Provide output of s2i usage

Returns:str