New table: docker_context

Feature request

What new feature do you want?

New table to list all available Docker contexts.

How is this new feature useful?

Tools like Podman and Rancher Desktop can create a new Docker context, and switch the context to the new one, and all docker commands will work.

Example with Rancher Desktop on my Mac:

➜  docker context ls
NAME                DESCRIPTION                               DOCKER ENDPOINT                                 ERROR
default             Current DOCKER_HOST based configuration   unix:///var/run/docker.sock                     
desktop-linux       Docker Desktop                            unix:///Users/myuser/.docker/run/docker.sock   
rancher-desktop *   Rancher Desktop moby context              unix:///Users/myuser/.rd/docker.sock  

That would support Rancher Desktop out of the box, and also Podman when Docker compatibility is added.

How can this be implemented?

It would be great that a docker_contexttable exists so that we can find out which contexts are available, and better yet, the other docker_ tables would use the Docker socket from the active context to get images, containers, etc.

Start by inspecting the existing docker_ tables and compare their behavior with docker context ls. Define the scope for a docker_context table and whether existing Docker tables should follow the active context; done should include a working context listing and clear behavior for those tables, with tests covering the result.