DockerCLI/docs/reference/commandline/inspect.md

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inspect The inspect command description and usage inspect, container, json

inspect

Usage:  docker inspect [OPTIONS] NAME|ID [NAME|ID...]

Return low-level information on Docker object(s) (e.g. container, image, volume,
network, node, service, or task) identified by name or ID

Options:
  -f, --format       Format the output using the given Go template
      --help         Print usage
  -s, --size         Display total file sizes if the type is container
      --type         Return JSON for specified type

Description

By default, docker inspect will render all results in a JSON array. If the container and image have the same name, this will return container JSON for unspecified type. If a format is specified, the given template will be executed for each result.

Go's text/template package describes all the details of the format.

Examples

Get an instance's IP address

For the most part, you can pick out any field from the JSON in a fairly straightforward manner.

$ docker inspect --format='{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' $INSTANCE_ID

Get an instance's MAC address

$ docker inspect --format='{{range .NetworkSettings.Networks}}{{.MacAddress}}{{end}}' $INSTANCE_ID

Get an instance's log path

$ docker inspect --format='{{.LogPath}}' $INSTANCE_ID

Get an instance's image name

$ docker inspect --format='{{.Container.Spec.Image}}' $INSTANCE_ID

List all port bindings

You can loop over arrays and maps in the results to produce simple text output:

$ docker inspect --format='{{range $p, $conf := .NetworkSettings.Ports}} {{$p}} -> {{(index $conf 0).HostPort}} {{end}}' $INSTANCE_ID

Find a specific port mapping

The .Field syntax doesn't work when the field name begins with a number, but the template language's index function does. The .NetworkSettings.Ports section contains a map of the internal port mappings to a list of external address/port objects. To grab just the numeric public port, you use index to find the specific port map, and then index 0 contains the first object inside of that. Then we ask for the HostPort field to get the public address.

$ docker inspect --format='{{(index (index .NetworkSettings.Ports "8787/tcp") 0).HostPort}}' $INSTANCE_ID

Get a subsection in JSON format

If you request a field which is itself a structure containing other fields, by default you get a Go-style dump of the inner values. Docker adds a template function, json, which can be applied to get results in JSON format.

$ docker inspect --format='{{json .Config}}' $INSTANCE_ID