nbdkit-cdi-plugin(1)

1nbdkit-cdi-plugin(1)                NBDKIT                nbdkit-cdi-plugin(1)
2
3
4

NAME

6       nbdkit-cdi-plugin - export a layer from a container image
7

SYNOPSIS

9        nbdkit cdi [name=]NAME[:TAG|@DIGEST] [layer=N]
10

DESCRIPTION

12       "nbdkit-cdi-plugin" (Containerized Data Importer plugin) is a plugin
13       for nbdkit(1) which downloads a container image using podman-pull(1)
14       and makes a single layer available over NBD.  The plugin is essentially
15       a convenient wrapper around podman(1) and jq(1) and requires both tools
16       to be installed.
17

EXAMPLES

19       Given a Containerized Data Importer (CDI) registry image containing a
20       VM disk, you can export the whole layer using:
21
22        $ nbdkit cdi docker://kubevirt/fedora-cloud-container-disk-demo
23
24       The layer exported over NBD is a tar file:
25
26        $ nbdcopy nbd://localhost - | file -
27        -: POSIX tar archive
28
29       To export only the VM disk image in this layer, combine this plugin
30       with nbdkit-tar-filter(1).  In this example when you run file(1) on the
31       tar entry within the layer it shows that it is a QCOW2 file:
32
33        $ nbdkit cdi docker://kubevirt/fedora-cloud-container-disk-demo \
34                --filter=tar tar-entry=./disk/downloaded \
35                --run 'nbdcopy "$uri" - | file -'
36        -: QEMU QCOW2 Image (v2), 4294967296 bytes
37

PARAMETERS

39       [name=]NAME[:TAG|@DIGEST]
40           The name or URI of the container image.  This is passed to
41           podman-pull(1).
42
43           "name=" is a magic config key and may be omitted in most cases.
44           See "Magic parameters" in nbdkit(1).
45
46       layer=N
47           Export the N'th layer (instead of layer 0).
48

ENVIRONMENT VARIABLES

50       "TMPDIR"
51           A temporary copy of the layer is created in "TMPDIR".  If this
52           environment variable is not set then /var/tmp is used instead.
53

FILES

55       $plugindir/nbdkit-cdi-plugin.so
56           The plugin.
57
58           Use "nbdkit --dump-config" to find the location of $plugindir.
59

VERSION

61       "nbdkit-cdi-plugin" first appeared in nbdkit 1.22.
62

AUTHORS

69       Richard W.M. Jones
70

COPYRIGHT

72       Copyright (C) 2020 Red Hat Inc.
73

LICENSE

75       Redistribution and use in source and binary forms, with or without
76       modification, are permitted provided that the following conditions are
77       met:
78
79       •   Redistributions of source code must retain the above copyright
80           notice, this list of conditions and the following disclaimer.
81
82       •   Redistributions in binary form must reproduce the above copyright
83           notice, this list of conditions and the following disclaimer in the
84           documentation and/or other materials provided with the
85           distribution.
86
87       •   Neither the name of Red Hat nor the names of its contributors may
88           be used to endorse or promote products derived from this software
89           without specific prior written permission.
90
91       THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY
92       EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
93       IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
94       PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE
95       LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
96       CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
97       SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
98       BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
99       WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
100       OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
101       ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
102
103
104
105nbdkit-1.30.7                     2022-07-10              nbdkit-cdi-plugin(1)