.nh
.TH umoci-raw-runtime-config(1) # umoci raw runtime-config - Generate an OCI runtime configuration for an image
Aleksa Sarai
DECEMBER 2016

.SH NAME
.PP
umoci raw runtime-config - Generate an OCI runtime configuration for an image


.SH SYNOPSIS
.PP
\fBumoci raw runtime-config\fP
\fB--image\fP=\fIimage\fP[:\fItag\fP]
[\fB--rootfs\fP=\fIrootfs\fP]
[\fB--rootless\fP]
\fIconfig\fP

.PP
\fBumoci raw config\fP
\fB--image\fP=\fIimage\fP[:\fItag\fP]
[\fB--rootfs\fP=\fIrootfs\fP]
[\fB--rootless\fP]
\fIconfig\fP


.SH DESCRIPTION
.PP
Generate a new OCI runtime configuration from an image, without extracting the
rootfs of said image. The configuration is written to the path given by
\fIconfig\fP, overwriting it if it exists already. This is one of the operations
done by \fBumoci-unpack\fP(1) when generating the runtime bundle, but because of
the overhead of extracting a root filesystem, \fBumoci-unpack\fP(1) is not
practical to be used many times if the user doesn't actually want to use the
root filesystem. Some fields require a root filesystem as a "source of truth",
and a source root filesystem can be specified using \fB--rootfs\fP\&. The other
flags have the same effects as with \fBumoci-unpack\fP(1).

.PP
Note however that the output of \fBumoci-raw-runtime-config\fP(1) is not
necessarily identical to the output from \fBumoci-unpack\fP(1). This is
especially true if \fB--rootfs\fP is not specified, which results in \fBumoci\fP(1)
leaving fields in the runtime spec to their defaults if computing their values
would require using the root filesystem as a source-of-truth.


.SH OPTIONS
.PP
The global options are defined in \fBumoci\fP(1).

.PP
\fB--image\fP=\fIimage\fP[:\fItag\fP]
  The OCI image tag which will be extracted to the \fIbundle\fP\&. \fIimage\fP must be a
  path to a valid OCI image and \fItag\fP must be a valid tag in the image. If
  \fItag\fP is not provided it defaults to "latest".

.PP
\fB--rootfs\fP=\fIrootfs\fP
  Use \fIrootfs\fP as a secondary source of truth when generating the runtime
  configuration (this is especially important for \fIConfig.User\fP conversion). If
  unspecified, any runtime fields that require a secondary source of truth to
  be filled with be left in their default values. This may result in
  discrepancies between the output of \fBumoci-unpack\fP(1) and
  \fBumoci-raw-runtime-config\fP(1).

.PP
\fB--rootless\fP
  Generate a rootless container configuration, similar to the configuration
  produced by \fBumoci-unpack\fP(1) when provided the \fB--rootless\fP flag.


.SH EXAMPLE
.PP
The following downloads an image from a \fBdocker\fP(1) registry using
\fBskopeo\fP(1) and then generates the \fIconfig.json\fP for that image.

.PP
.RS

.nf
% skopeo copy docker://opensuse/amd64:42.2 oci:image:latest
% umoci raw runtime-config --image image:latest config.json

.fi
.RE

.PP
If a root filesystem is already present, it is possible to specify it with the
\fB--rootfs\fP flag. This will source the root filesystem for conversion
operations that necessitate it.

.PP
.RS

.nf
% skopeo copy docker://opensuse/amd64:42.2 oci:image:latest
# umoci unpack --image image bundle
% umoci raw runtime-config --image image --rootfs bundle/rootfs config.json

.fi
.RE


.SH SEE ALSO
.PP
\fBumoci\fP(1), \fBumoci-repack\fP(1), \fBrunc\fP(8)