--- title: "inspect" description: "The inspect command description and usage" keywords: "inspect, container, json" --- # inspect ```markdown 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 Docker inspect provides detailed information on constructs controlled by Docker. By default, `docker inspect` will render results in a JSON array. ## Request a custom response format (--format) If a format is specified, the given template will be executed for each result. Go's [text/template](https://golang.org/pkg/text/template/) package describes all the details of the format. ## Specify target type (--type) `--type container|image|node|network|secret|service|volume|task|plugin` The `docker inspect` command matches any type of object by either ID or name. In some cases multiple type of objects (for example, a container and a volume) exist with the same name, making the result ambiguous. To restrict `docker inspect` to a specific type of object, use the `--type` option. The following example inspects a _volume_ named "myvolume" ```console $ docker inspect --type=volume myvolume ``` ### Inspect the size of a container (-s, --size) The `--size`, or short-form `-s`, option adds two additional fields to the `docker inspect` output. This option only works for containers. The container doesn't have to be running, it also works for stopped containers. ```console $ docker inspect --size mycontainer ``` The output includes the full output of a regular `docker inspect` command, with the following additional fields: - `SizeRootFs`: the total size of all the files in the container, in bytes. - `SizeRw`: the size of the files that have been created or changed in the container, compared to it's image, in bytes. ```console $ docker run --name database -d redis 3b2cbf074c99db4a0cad35966a9e24d7bc277f5565c17233386589029b7db273 $ docker inspect --size database -f '{{ .SizeRootFs }}' 123125760 $ docker inspect --size database -f '{{ .SizeRw }}' 8192 $ docker exec database fallocate -l 1000 /newfile $ docker inspect --size database -f '{{ .SizeRw }}' 12288 ``` ## 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. ```console $ docker inspect --format='{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' $INSTANCE_ID ``` ### Get an instance's MAC address ```console $ docker inspect --format='{{range .NetworkSettings.Networks}}{{.MacAddress}}{{end}}' $INSTANCE_ID ``` ### Get an instance's log path ```console $ docker inspect --format='{{.LogPath}}' $INSTANCE_ID ``` ### Get an instance's image name ```console $ docker inspect --format='{{.Config.Image}}' $INSTANCE_ID ``` ### List all port bindings You can loop over arrays and maps in the results to produce simple text output: ```console $ 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. ```console $ 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. ```console $ docker inspect --format='{{json .Config}}' $INSTANCE_ID ```