Lxd: Ubuntu-Core container image defaults to the edge channel, not stable

Created on 14 Oct 2018 · 3Comments · Source: lxc/lxd

Required information

Distribution: Ubuntu
Distribution version: 16.04
The output of "lxc info" or if that fails:
- Kernel version: 4.15
- LXC version:
- LXD version: 3.6
- Storage backend in use: zfs

Issue description

When you create a LXD container with Ubuntu Core according to https://blog.ubuntu.com/2017/02/27/ubuntu-core-in-lxd-containers
the Ubuntu Core defaults to the edge channel for the snaps core, pc, pc-kernel.

Steps to reproduce

Create an Ubuntu Core LXD container,

$ lxc launch images:ubuntu-core/16 mycore
Creating mycore
Starting mycore

Get a shell in the container and check the tracking channel for core (also, pc, pc-kernel).

$ lxc shell mycore
root@mycore:~# snap info core
name:      core
summary:   snapd runtime environment
publisher: canonical
contact:   [email protected]
description: |
  The core runtime environment for snapd
type:        core
snap-id:     99T7MUlRhtI3U0QFgl5mXXESAiSwt776
tracking:    edge
installed:   16-2.30+git477.ccba80a (3850) 87MB core
refreshed:   2018-01-03 04:22:44 +0000 UTC
channels:                        
  stable:    16-2.35.2    (5548) 92MB -
  candidate: 16-2.35.4    (5662) 92MB -
  beta:      16-2.36~pre2 (5714) 92MB -
  edge:      16-2.36~pre2 (5717) 92MB -
root@mycore:~#

What happens: the core snap is tracking edge
What should happen: the core snap should be tracking stable

Information to attach

[ ] Any relevant kernel output (dmesg)
[x] Container log (lxc info NAME --show-log)
[ ] Container configuration (lxc config show NAME --expanded)
[ ] Main daemon log (at /var/log/lxd/lxd.log or /var/snap/lxd/common/lxd/logs/lxd.log)
[ ] Output of the client with --debug
[ ] Output of the daemon with --debug (alternatively output of lxc monitor while reproducing the issue)

$ sudo cat /var/snap/lxd/common/lxd/logs/mycore/console.log
lzcat: unexpected EOF
/sbin/init: .: line 43: can't open '/initrd/scripts/ubuntu-core-rootfs'

Source

simos

👍1

All 3 comments

If you switch from edge to stable and try to snap refresh, you get the following:

$ lxc shell mycore root@mycore:~# snap info core name: core summary: snapd runtime environment publisher: canonical contact: [email protected] description: | The core runtime environment for snapd type: core snap-id: 99T7MUlRhtI3U0QFgl5mXXESAiSwt776 tracking: edge installed: 16-2.30+git477.ccba80a (3850) 87MB core refreshed: 2018-01-03 04:22:44 +0000 UTC channels: stable: 16-2.35.2 (5548) 92MB - candidate: 16-2.35.4 (5662) 92MB - beta: 16-2.36~pre2 (5714) 92MB - edge: 16-2.36~pre2 (5717) 92MB - root@mycore:~# snap switch core --stable "core" switched to the "stable" channel root@mycore:~# snap switch pc --stable "pc" switched to the "stable" channel root@mycore:~# snap switch pc-kernel --stable "pc-kernel" switched to the "stable" channel root@mycore:~# snap refresh 2018-10-14T17:35:11Z INFO Waiting for restart... 2018-10-14T17:35:43Z INFO Waiting for restart... 2018-10-14T17:35:44Z INFO Waiting for restart... 2018-10-14T17:35:45Z INFO Waiting for restart... 2018-10-14T17:35:48Z INFO Waiting for restart... 2018-10-14T17:35:49Z INFO Waiting for restart... 2018-10-14T17:40:49Z INFO Waiting for restart... 2018-10-14T17:43:50Z INFO Waiting for restart... Setup snap "core" (5548) security profiles (phase 2) Exit 129

That is, the update fails and the container is stopped. You cannot start the container again.

simos on 14 Oct 2018

👍1

The image being based on edge was an unfortunate consequence of the Ubuntu Core team never updating the stable image... I've re-checked now and there has been a new stable image publish in August this year, so I switched the build script over to that, let's see what that gives us.