Sebastiaan van Stijn e9ae9f788b
docker inspect: add support for swarm configs
The docker inspect command did not inspect configs. This patch adds support for
it, and while at it, also sorts the list of objects in runInspect.

Before this patch:

    docker config create myconfig ./codecov.yml
    danpeyh8qzb30vgdj9fr665l1

    docker inspect --format='{{.ID}}' myconfig
    []
    Error: No such object: myconfig

    docker inspect --format='{{.ID}}' --type=config myconfig
    "config" is not a valid value for --type

With this patch:

    docker inspect --format='{{.ID}}' myconfig
    danpeyh8qzb30vgdj9fr665l1

    docker inspect --format='{{.ID}}' --type=config myconfig
    danpeyh8qzb30vgdj9fr665l1

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2024-10-24 18:32:32 +02:00

135 lines
5.4 KiB
Markdown

# inspect
<!---MARKER_GEN_START-->
Return low-level information on Docker objects
### Options
| Name | Type | Default | Description |
|:---------------------------------------|:---------|:--------|:-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [`-f`](#format), [`--format`](#format) | `string` | | Format output using a custom template:<br>'json': Print in JSON format<br>'TEMPLATE': Print output using the given Go template.<br>Refer to https://docs.docker.com/go/formatting/ for more information about formatting output with templates |
| [`-s`](#size), [`--size`](#size) | `bool` | | Display total file sizes if the type is container |
| [`--type`](#type) | `string` | | Return JSON for specified type |
<!---MARKER_GEN_END-->
## Description
Docker inspect provides detailed information on constructs controlled by Docker.
By default, `docker inspect` will render results in a JSON array.
### <a name="format"></a> Format the output (--format)
If a format is specified, the given template will be executed for each result.
Go's [text/template](https://pkg.go.dev/text/template) package describes
all the details of the format.
### <a name="type"></a> Specify target type (--type)
`--type config|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
```
### <a name="size"></a> 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, specify 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
```