Make migration.stateful also apply to containers

[stgraber]

Containers should also require migration.stateful for live-migration, stateful stop and stateful snapshots.

This should make it less likely to have folks run into weird CRIU errors when all they wanted was copy a container to another system.

[Abhiram824]

Hello, could I be assigned to this issue as well?

[stgraber]

So that one shouldn't be too difficult to sort out.

This will need a new API extension in doc/api-extensions.md and internal/version/api.go, let's call it container_migration_stateful.

Then you'll first need to modify internal/instance/config.go to move the config key migration.stateful from InstanceConfigKeysVM to InstanceConfigKeysAny and remove the condition on it`.

This will then require you run make update-metadata to re-generate our config key definitions.

Once that's done, you can start editing internal/server/instance/drivers/driver_lxc.go to add the checks for that configuration key.

You should require the config key is set to true (util.IsTrue) in:

• Start() (when stateful is true)
• Stop() (when stateful is true)
• snapshot() (when stateful is true)

Commit list should look something like:

• api: container_migration_stateful
• internal/instance: Add migration.stateful to containers
• incusd/instance/lxc: Add checks for migration.stateful

[dhruvvnistala]

Hi, commenting on this post as per our discussion on #255

[Abhiram824]

Hello, we made some progress and created a PR #781. Please let us know if everything looks okay.