umoci-repack(1)(#)

Aleksa Sarai DECEMBER 2016

NAME
umoci repack - Repacks an OCI runtime bundle into an image tag

SYNOPSIS
umoci repack --image=image[:tag] [--compress=compression-type] [--no-history] [--history.comment=comment] [--history.created_by=created_by] [--history.author=author] [--history-created=date] [--refresh-bundle] bundle

DESCRIPTION
Given a modified OCI bundle extracted with umoci-unpack(1) (at the given path bundle), umoci-repack(1) computes the filesystem delta for the OCI bundle's rootfs. The delta is used to generate a delta layer, which is then appended to the original image manifest (that was used as an argument to umoci-unpack(1)) and tagged as a new image tag. Between a call to umoci-unpack(1) and umoci-repack(1) users SHOULD NOT modify the OCI image in any way (specifically you MUST NOT use umoci-gc(1)).

All --uid-map and --gid-map settings are implied from the saved values specified in umoci-unpack(1), so they are not available for umoci-repack(1).

If --no-history was not specified, a history entry is appended to the tagged OCI image for this change (with the various --history. flags controlling the values used). To view the history, see umoci-stat(1).

Note that the original image tag (used with umoci-unpack(1)) will not be modified unless the target of umoci-repack(1) is the original image tag.

OPTIONS
The global options are defined in umoci(1).

--image=image[:tag]
  The destination tag for the repacked OCI image. image must be a path to a
  valid OCI image (and the same image used in umoci-unpack(1) to create
  the bundle) and tag must be a valid tag name. If another tag already has
  the same name as tag it will be overwritten. If tag is not provided it
  defaults to "latest".

--compress=compression-type
  Specify the compression type to use when creating a new layer. Supported
  compression types are none, gzip, and zstd. umoci-unpack(1)
  transparently supports all compression methods you can specify with
  --compress.

  The special value auto will cause umoci(1) to auto-select the most
  appropriate compression algorithm based on what previous layers are
  compressed with (it will try to use the most recent layer's compression
  algorithm which it supports). Note that auto will never select none
  compression automatically, as not compressing tar(1) archives is really
  not advisable.

  If no compression-type is provided, it defaults to auto.

--no-history
  Causes no history entry to be added for this operation. This is not
  recommended for use with umoci-repack(1), since it results in the history not
  including all of the image layers -- and thus will cause confusion with tools
  that look at image history.

--history.comment=comment
  Comment for the history entry corresponding to this modification of the image
  If unspecified, umoci(1) will generate an implementation-dependent value.

--history.created_by=created_by
  CreatedBy entry for the history entry corresponding to this modification of
  the image. If unspecified, umoci(1) will generate an
  implementation-dependent value.

--history.author=author
  Author value for the history entry corresponding to this modification of the
  image. If unspecified, this value will be the image's author value after
  any modifications were made by this call of umoci-config(1).

--history-created=date
  Creation date for the history entry corresponding to this modifications of
  the image. This must be an ISO8601 formatted timestamp (see date(1)). If
  unspecified, the current time is used.

--refresh-bundle
  Whether to update the OCI bundle's metadata (i.e. mtree and umoci
  metadata) after repacking the image. If set, then the new state of
  the bundle should be equivalent to unpacking the new image tag.

EXAMPLE
The following downloads an image from a docker(1) registry using skopeo(1), unpacks it with umoci-unpack(1), modifies it and then repacks it.
    % skopeo copy docker://opensuse/amd64:42.2 oci:image:latest
    # umoci unpack --image image bundle
    # touch bundle/rootfs/a_new_file
    # umoci repack --image image:new-42.2 bundle

SEE ALSO
umoci(1), umoci-unpack(1)