ANN: LXD Images

[Paweł A. Gajda]

PLD images have been merged by LXC-CI ([1]), means that create PLD's
LXD containers is now as easy as:

$ lxc launch images:pld c1

2 architectures are available:

$ lxc image ls -c=fdas images:pld
+--------------+------------------------------------+--------------+---------+
| FINGERPRINT  |            DESCRIPTION             | ARCHITECTURE |  SIZE   |
+--------------+------------------------------------+--------------+---------+
| 6289f88a4da8 | Pld current i386 (20200316_20:20)  | i686         | 25.78MB |
+--------------+------------------------------------+--------------+---------+
| c6e392000455 | Pld current amd64 (20200316_20:46) | x86_64       | 27.84MB |
+--------------+------------------------------------+--------------+---------+

Images are build continuously by https://jenkins.linuxcontainers.org,
so we get up to date image every week.

Technically, LXD images are based on glen's Docker images ([2]),
mirrored to dockerhub ([3]) (via github [4]), cause distrobuilder
tool ([5]) used by LXC-CI cannot directly pull from registry.gitlab.com.

Distrobuilder config and build script are available in separate repo ([6])

TODO:
1) Push docker images directly from gitlab (glen?) to avoid quite
   messy mirroring.
2) Sign images somehow (?)
3) (huge) Make an official, continously build PLD minimal ISO
   and then add VM's images as well (LXD supports VM's now).

[1] https://github.com/lxc/lxc-ci/pull/135
[2] https://gitlab.com/pld-linux/pld
[3] https://hub.docker.com/search?q=pldlinux
[4] https://github.com/mistoo/dockerhub-pld-images
[5] https://github.com/lxc/distrobuilder/
[6] https://github.com/mistoo/pld-lxd-image.