Show the history of when and how an image was created.

# EXAMPLES
    $ docker history fedora
    IMAGE          CREATED          CREATED BY                                      SIZE                COMMENT
    105182bb5e8b   5 days ago       /bin/sh -c #(nop) ADD file:71356d2ad59aa3119d   372.7 MB
    73bd853d2ea5   13 days ago      /bin/sh -c #(nop) MAINTAINER Lokesh Mandvekar   0 B
    511136ea3c5a   10 months ago                                                    0 B                 Imported from -

## Display comments in the image history
The `docker commit` command has a **-m** flag for adding comments to the image. These comments will be displayed in the image history.

    $ sudo docker history docker:scm
    IMAGE               CREATED             CREATED BY                                      SIZE                COMMENT
    2ac9d1098bf1        3 months ago        /bin/bash                                       241.4 MB            Added Apache to Fedora base image
    88b42ffd1f7c        5 months ago        /bin/sh -c #(nop) ADD file:1fd8d7f9f6557cafc7   373.7 MB            
    c69cab00d6ef        5 months ago        /bin/sh -c #(nop) MAINTAINER Lokesh Mandvekar   0 B                 
    511136ea3c5a        19 months ago                                                       0 B                 Imported from -

### Format the output

The formatting option (`--format`) will pretty-prints history output
using a Go template.

Valid placeholders for the Go template are listed below:

| Placeholder     | Description |
| --------------- | ----------- |
| `.ID`           | Image ID    |
| `.CreatedSince` | Elapsed time since the image was created if `--human=true`, otherwise timestamp of when image was created |
| `.CreatedAt`    | Timestamp of when image was created |
| `.CreatedBy`    | Command that was used to create the image |
| `.Size`         | Image disk size |
| `.Comment`      | Comment for image |

When using the `--format` option, the `history` command will either
output the data exactly as the template declares or, when using the
`table` directive, will include column headers as well.

The following example uses a template without headers and outputs the
`ID` and `CreatedSince` entries separated by a colon for all images:

```bash
$ docker images --format "{{.ID}}: {{.CreatedSince}} ago"

cc1b61406712: 2 weeks ago
<missing>: 2 weeks ago
<missing>: 2 weeks ago
<missing>: 2 weeks ago
<missing>: 2 weeks ago
<missing>: 3 weeks ago
<missing>: 3 weeks ago
<missing>: 3 weeks ago
```
