Docker Container¶
Aside from methods in API definition - conu.apidefs.container.Container
, DockerContainer implements following methods:
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class
conu.
DockerContainer
(image, container_id, name=None, popen_instance=None)¶ These methods are specific to this backend:
These generic methods are not implemented in this backend:
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__init__
(image, container_id, name=None, popen_instance=None)¶ Parameters: - image – DockerImage instance
- container_id – str, unique identifier of this container
- name – str, pretty container name
- popen_instance – instance of Popen (if container was created using method via_binary, this is the docker client process)
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copy_from
(src, dest)¶ copy a file or a directory from container or image to host system.
Parameters: - src – str, path to a file or a directory within container or image
- dest – str, path to a file or a directory on host system
Returns: None
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copy_to
(src, dest)¶ copy a file or a directory from host system to a container
Parameters: - src – str, path to a file or a directory on host system
- dest – str, path to a file or a directory within container
Returns: None
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delete
(force=False, volumes=False, **kwargs)¶ remove this container; kwargs indicate that some container runtimes might accept more parameters
Parameters: - force – bool, if container engine supports this, force the functionality
- volumes – bool, remove also associated volumes
Returns: None
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execute
(command, blocking=True, exec_create_kwargs=None, exec_start_kwargs=None)¶ Execute a command in this container – the container needs to be running.
If the command fails, a ConuException is thrown.
This is a blocking call by default and writes output of the command to logger using the INFO level – this behavior can be changed if you set the argument blocking to False.
If not blocking, you should consume the returned iterator in order to see logs or know when the command finished:
for line in container.execute(["ping", "-c", "4", "8.8.8.8"], blocking=False): print(line) print("command finished")
Parameters: - command – list of str, command to execute in the container
- blocking – bool, if True blocks until the command finishes
- exec_create_kwargs – dict, params to pass to exec_create()
- exec_start_kwargs – dict, params to pass to exec_start()
Returns: iterator if non-blocking or list of bytes if blocking
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exit_code
()¶ get exit code of container. Return value is 0 for running and created containers
Returns: int
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get_IPv4s
()¶ Return all known IPv4 addresses of this container. It may be possible that the container has disabled networking: in that case, the list is empty
Returns: list of str
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get_id
()¶ get unique identifier of this container
Returns: str
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get_metadata
(refresh=True)¶ return cached metadata by default
Parameters: refresh – bool, returns up to date metadata if set to True Returns: dict
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get_port_mappings
(port=None)¶ Get list of port mappings between container and host. The format of dicts is:
{“HostIp”: XX, “HostPort”: YY};When port is None - return all port mappings. The container needs to be running, otherwise this returns an empty list.
Parameters: port – int or None, container port Returns: list of dict or None; dict when port=None
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get_ports
()¶ get ports specified in container metadata
Returns: list of str
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get_status
()¶ Get status of container
Returns: one of: ‘created’, ‘restarting’, ‘running’, ‘paused’, ‘exited’, ‘dead’
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inspect
(refresh=True)¶ return cached metadata by default (a convenience method)
Parameters: refresh – bool, returns up to date metadata if set to True Returns: dict
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is_port_open
(port, timeout=2)¶ check if given port is open and receiving connections on container ip_address
Parameters: - port – int, container port
- timeout – int, how many seconds to wait for connection; defaults to 2
Returns: True if the connection has been established inside timeout, False otherwise
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is_running
()¶ returns True if the container is running, this method should always ask the API and should not use a cached value
Returns: bool
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kill
(signal=None)¶ send a signal to this container (bear in mind that the process won’t have time to shutdown properly and your service may end up in an inconsistent state)
Parameters: signal – str or int, signal to use for killing the container (SIGKILL by default) Returns: None
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logs
(follow=False)¶ Get logs from this container. Every item of the iterator contains one log line terminated with a newline. The logs are encoded (they are bytes, not str).
Let’s look at an example:
image = conu.DockerImage("fedora", tag="27") command = ["bash", "-c", "for x in `seq 1 5`; do echo $x; sleep 1; done"] container = image.run_via_binary(command=command) for line in container.logs(follow=True): print(line)
This will output
b'1\n' b'2\n' b'3\n' b'4\n' b'5\n'
Parameters: follow – bool, provide new logs as they come Returns: iterator (of bytes)
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logs_in_bytes
()¶ Get output of container in bytes.
Returns: bytes
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logs_unicode
()¶ Get output of container decoded using utf-8.
Returns: str
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mount
(mount_point=None)¶ mount container filesystem
Parameters: mount_point – str, directory where the filesystem will be mounted Returns: instance of DockerContainerFS
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start
()¶ start current container - the container has to be created
Returns: None
-
stop
()¶ stop this container
Returns: None
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wait
(timeout=None)¶ Block until the container stops, then return its exit code. Similar to the
docker wait
command.Parameters: timeout – int, Request timeout Returns: int, exit code
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wait_for_port
(port, timeout=10, **probe_kwargs)¶ block until specified port starts accepting connections, raises an exc ProbeTimeout if timeout is reached
Parameters: - port – int, port number
- timeout – int or float (seconds), time to wait for establishing the connection
- probe_kwargs – arguments passed to Probe constructor
Returns: None
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write_to_stdin
(message)¶ - Write provided text to container’s standard input. In order to make this function work, there needs to be several conditions met:
- the container needs to be running
- the container needs to have stdin open
- the container has to be created using method run_via_binary_in_foreground
For more info see documentation in run_via_binary_in_foreground()
Parameters: message – str or bytes, text to be written to container standard input
-
-
class
conu.
DockerRunBuilder
(command=None, additional_opts=None)¶ helper to execute docker run – users can easily change or override anything
-
__init__
(command=None, additional_opts=None)¶ Build docker run command
Parameters: - command – list of str, command to run in the container, examples: - [“ls”, “/”] - [“bash”, “-c”, “ls / | grep bin”]
- additional_opts – list of str, additional options for docker run
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-
class
conu.
DockerContainerFS
(container, mount_point=None)¶ These generic methods are not implemented in this backend:
-
__init__
(container, mount_point=None)¶ Raises CommandDoesNotExistException if the command is not present on the system.
Parameters: - container – instance of DockerContainer
- mount_point – str, directory where the filesystem will be mounted
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