Notes on containerd

containerd_notes.md

Start the containerd daemon

$ containerd -l debug
INFO[0000] starting containerd                           module=containerd revision=bb7b41ad7b3d3eb8b978abee2f5b7a1395b41f4f version=v1.0.0-alpha2-32-gbb7b41ad

Fetch an image

$ ctr content fetch docker.io/library/redis:latest
docker.io/library/redis:latest:                                                   resolved       |++++++++++++++++++++++++++++++++++++++|
manifest-sha256:a7776895af32e34b1fef997e26c79fa988b40c5cf2a3fb48dc22e0584b648d82: done           |++++++++++++++++++++++++++++++++++++++|
layer-sha256:1e448b71a4f0fc223fe100d3c8ccbc8c601065c16fd32f958fdc62bb549f9979:    done           |++++++++++++++++++++++++++++++++++++++|
config-sha256:d4f259423416b3c82b46e1caf01829ac3a99a211dfc691c9d862464768112e7f:   done           |++++++++++++++++++++++++++++++++++++++|
layer-sha256:5233d9aed181939c195efdc439722dc3e56f4f8d8d80f8844d0b7881f6ce9f99:    done           |++++++++++++++++++++++++++++++++++++++|
layer-sha256:ca1b33d3f1140aa85d8fa6df4d8bd6fb270697f2da59e8e4759dead245d87899:    done           |++++++++++++++++++++++++++++++++++++++|
layer-sha256:920cdc17d3c261b5b00622fa8e135a39e27a04859d3ee4a062ed126506d10c13:    done           |++++++++++++++++++++++++++++++++++++++|
layer-sha256:6f939f708ee9a8df2f6ce80bacb7a4e7600bb27bf9615bf5371df0637e20a211:    done           |++++++++++++++++++++++++++++++++++++++|
layer-sha256:4ba0e186289de69568d40148a2cb0e43b4af1f7048b55b02f985ce42e1e5972a:    done           |++++++++++++++++++++++++++++++++++++++|
elapsed: 5.8 s                                                                    total:  37.4 M (6.4 MiB/s)

List known images

$ ctr images list
REF                            TYPE                                                 DIGEST                                                                  SIZE     LABELS
docker.io/library/redis:latest application/vnd.docker.distribution.manifest.v2+json sha256:a7776895af32e34b1fef997e26c79fa988b40c5cf2a3fb48dc22e0584b648d82 37.4 MiB -

Unpack rootfs into containerd snapshotter

$ ctr rootfs unpack sha256:a7776895af32e34b1fef997e26c79fa988b40c5cf2a3fb48dc22e0584b648d82
unpacking sha256:a7776895af32e34b1fef997e26c79fa988b40c5cf2a3fb48dc22e0584b648d82 (application/vnd.docker.distribution.manifest.v2+json)...done

Run a container

$ ctr run docker.io/library/redis:latest teddyredis
1:C 03 Aug 12:33:41.943 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
...