NAME

umoci stat - Display status information about an image tag

SYNOPSIS

umoci stat --image=image[:tag] [--json]

DESCRIPTION

Generates various pieces of status information about an image tag, including the history of the image.

WARNING: Do not depend on the output of this tool. Previously we recommended the use of --json as the "stable" interface but this interface will be reworked in future.

OPTIONS

The global options are defined in umoci(1).

--image=image[:tag]
The OCI image tag to display information about. image must be a path to a
valid OCI image and tag must be a valid tag in the image. If tag is not
provided it defaults to "latest".

--json
Output the status information as a JSON encoded blob.

FORMAT

The format of the --json blob is as follows. Many of these fields come from the OCI image specification ⟨https://github.com/opencontainers/image-spec⟩.

{
  # This is the set of history entries for the image.
  "history": [
    {
      "layer":       <descriptor>, # null if empty_layer is true
      "diff_id":     <diffid>,
      "created":     <created>,
      "created_by":  <created_by>,
      "author":      <author>,
      "empty_layer": <empty_layer>
    }...
  ]
}

In future versions of umoci(1) there may be extra fields added to the above structure. However, the currently defined fields will always be set (until a backwards-incompatible release is made).

EXAMPLE

The following gets information about an image downloaded from a docker(1) registry using skopeo(1).

% skopeo copy docker://opensuse/amd64:42.2 oci:image:latest
% umoci stat --image image
LAYER                                                                   CREATED                        CREATED BY                                                                                        SIZE     COMMENT
<none>                                                                  2016-12-05T22:52:33.085510751Z /bin/sh -c #(nop)  MAINTAINER SUSE Containers Team <containers@suse.com>                          <none>
sha256:e800e72a0a88984bd1b47f4eca1c188d3d333dc8e799bfa0a02ea5c2697216d5 2016-12-05T22:52:46.570617134Z /bin/sh -c #(nop) ADD file:6e0044405547c4c209fac622b3c6ddc75e7370682197f7920ec66e4e5e00b180 in /  49.25 MB