inspect

Modified: 24 Apr 2018 22:47 UTC
Stability: Unknown

Usage: docker inspect [OPTIONS] CONTAINER|IMAGE [CONTAINER|IMAGE...]

Return low-level information on a container or image

  -f, --format=""            Format the output using the given go template
  -s, --size                 Display total file sizes if the type is container
  --type=container|image     Return JSON for specified type, permissible
                             values are "image" or "container"

By default, this will render all results in a JSON array. 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='{{.NetworkSettings.IPAddress}}' $INSTANCE_ID

Get an instance's MAC Address:

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

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

Get an instance's log path:

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

List All Port Bindings:

One 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, so 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 config:

The .Field syntax doesn't work when the field contains JSON data, but the template language's custom json function does. The .config section contains complex JSON object, so to grab it as JSON, you use json to convert the configuration object into JSON.

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

Divergence

Some fields, including the following, are irrelevent to containers on Triton and are never populated.

Also note that the Config.Labels will include the special 'com.joyent.package' value which will be set to the current name of the package associated with this VM.

Read more about container security on Triton and see notes about exit status.

The -s and --size options are currently unsupported.

Please contact Joyent support or file a ticket if you discover any additional divergence.