Container dependencies

LXD
1

Now that LXD has the READY-event we might be able to implement container startup-dependencies based on that.

We already have:

  • boot.autostart to force startup on boot
  • boot.autostart.priority to specify startup order
  • boot.autostart.delay to make containers “wait” longer until others are up

In case you want to specify dependencies, the last two are kind of a workaround and would not be required if we could specify dependencies by name directly. LXD would only start the container if all instances in that list have sent the READY event.
This could look like this:

boot.autostart.dependenies:
  - container0
  - container1

If you manually lxc start a container with dependencies it should probably implicitly start all the dependencies as well.

Such functionality would be a huge improvement already but there might be cases where you want to wait for a container if they are about to be started, but they’re not a hard dependency. That’d be similar to systemd’s After=.

2

Please could you open an issue describing your idea here:

Thanks!

3

Of course, here you go: Container dependencies · Issue #10947 · lxc/lxd · GitHub

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