How to use Docker contexts

Docker contexts allow you to connect to docker daemons other than the local one. This is similar to the -H argument of the Docker command.

Contexts commands allow you to declare, save, list local and remote Docker daemons and Kubernetes endpoints that you have.

An exemple here with python-on-whales:

from python_on_whales import docker, DockerContextConfig

new_context = docker.context.create(
    "my_remote_ssh_server",
    docker=DockerContextConfig(host="ssh://ubuntu@52.57.163.75"),
    description="my server ssh with a lot more power"
)
print(docker.context.list())
# [python_on_whales.Context(name='default', endpoints={'docker': ContextEndpoint(host='unix:///var/run/docker.sock', skip_tls_verify=False)}),
# python_on_whales.Context(name='my_remote_ssh_server', endpoints={'docker': ContextEndpoint(host='ssh://ubuntu@52.57.163.75', skip_tls_verify=False)})]
new_context.use()
# it's the same to use docker.context.use("my_remote_ssh_server") or docker.context.use(new_context)

print(docker.ps()) # will list the containers in the remote server
# [python_on_whales.Container(id=...), python_on_whales.Container(id=...)]
# return to the local docker daemon
docker.context.use("default")
print(docker.ps()) # will list the containers running locally
# [python_on_whales.Container(id=...)]

Note that for this simple use case, it's equivalent to use the -H option of the Docker client like so:

from python_on_whales import DockerClient

docker = DockerClient(host="ssh://ubuntu@52.57.163.75")

print(docker.ps())

ContextCLI

create

create(context_name, default_stack_orchestrator=None, description=None, from_=None, docker=None, kubernetes=None)

Creates a new context

Parameters:

Name	Type	Description	Default
`context_name`	`str`	name of the context to create	required
`default_stack_orchestrator`	`Optional[str]`	Default orchestrator for stack operations to use with this context (swarm\|kubernetes\|all)	`None`
`description`	`Optional[str]`	Description of the context	`None`
`docker`	`Union[Dict[str, Any], DockerContextConfig, None]`	Set the docker endpoint, you can use a dict of a class to specify the options. The class is `python_on_whales.DockerContextConfig`.	`None`
`from_`	`Optional[ValidContext]`	Create context from a named context	`None`
`kubernetes`	`Union[Dict[str, Any], KubernetesContextConfig, None]`	Set the kubernetes endpoint. You can use a dict or a class to specify the options. The class is `python_on_whales.KubernetesContextConfig`.	`None`

inspect

inspect(x=None)

Returns the context object. If no argument is provided, returns the current context.

list

list()

List all Docker contexts available

Returns

`List[python_on_whales.Context]`

remove

remove(x, force=False)

Removes one or more contexts

Parameters:

Name	Type	Description	Default
`x`	`Union[ValidContext, List[ValidContext]]`	One or more contexts, empty list means no-op.	required
`force`	`bool`	Force the removal of this context	`False`

update

update()

Not yet implemented

use

use(context)

Set the default context

Parameters:

Name	Type	Description	Default
`context`	`ValidContext`	The context to set as default	required