Having just gotten burned by a 3.21 configuration change that killed all my containers, I’m wondering if there is a good place to find the current version of LXD documented (other than reading the source code).
It would appear that any books or articles written more than a year ago are largely obsolete, at this point.
I’m running into issues like not being able to find the container yaml files, even though LXD 3.21 is installed in a vanilla fashion directly from github.
https://linuxcontainers.org/lxd/docs/master/
When it comes to LXD, anything under /var/lib/lxd is under LXD’s control. We may move that data around, not mount things anymore or move things around at any time. Making assumptions based on what’s currently there is something you should be careful of as we will not treat such breakages as regressions.
The only thing that’s guaranteed as far as filesystem layout under /var/lib/lxd is that the unix socket will be at unix.socket, everything else may change at any time.
In your case, I suspect you got hit by us doing a better job at not keeping mounted things that aren’t actively in use. Most storage drivers were already implementing that though a few weren’t doing it quite right, LXD 3.20 and 3.21 (only for Ceph on that one) are now much better behaved in that way.
Just to clarify, are you saying one shouldn’t try and edit these yaml files by hand? It kind of looks like the configuration information has been moved into a database – is this correct?
But my main question was about documentation; i.e. what’s available and where.
The link that @stgraber gave you, is the top link to the LXD documentation. You start there and are directed the the reference documentation of LXD.
There are several (mostly four) types of technical documentation. I suppose you are missing a user-guide type of documentation.
The yaml files are only backup copies for disaster recovery, modifying them will not have any effect other than potentially screwing up your backups.
@stgraber: Thanks for the documentation link and that explanation, and many apologies for somehow missing the obviously displayed link to the documentation: I blame exhaustion from everything that could crash crashing yesterday.
Actually, I like to master a deep understanding of how things work, but LXD is a great technology that fills an important niche. It would be a lot more popular if there were some good user documentation out there. Most people still think you can only use it on Ubuntu, when in fact I’m pretty sure it runs better (or at least as well) on Arch. I don’t use RHEL-based systems if I can avoid them, so can’t speak to that.