Since service daemon actors may be cancelled remotely by clients (who
maybe also requested said daemon-actor's spawn in the first place) we
specifically ignore `tractor.ContextCancelled`s from the `ctx.wait()`
inside `Services.start_service_task()` to avoid crashing the service
mngr, and thus for now `pikerd`, (which **does** happen now due to
updated and more explicit remote cancellation semantics implemented in
`tractor`) since the `.canceller` field is not going to match the
`pikerd` uid in such cases!
This explicit check makes sense since the `Services` mngr is built to
allow remote requests to "spawn-n-supervise service actors" where the
services can remain persistent but also cancelled later as requested. We
may want to consider only allowing cancellation by actors who requested
spawn in the future tho?
Also change to more explicit imports to `tractor` types for annots
throughout the sub-pkg.
Allows for using the `Services.cancel_service()` api for explicit
cancellation in tests and eventually for remote teardown. Change
`.start_ahab()` to an `@acm` `start_ahab_service()` and just yield back
the same values we were returning prior. Also fix the logging (level) to
actually reflect what's passed in - we weren't using the correct name
/ instance from the `.sevice` subpkg..
Needed to move the startup sequence inside the `try:` block to guarantee
we always do the (now shielded) `.cancel()` call if we get a cancel
during startup.
Also, support an optional `started_afunc` field in the config if
backends want to just provide a one-off blocking async func to sync
container startup. Add a `drop_root_perms: bool` to allow persisting
sudo perms for testing or dyanmic container spawning purposes.
Tyler Goodlet