incus: add completions for storage pools and volumes

[adamcstephens]

Is it ok to bring in code from internal/server ? Or is there another place to get the list of all available storage config options besides

incus/internal/server/storage/utils.go

Line 478 in cff35a2

func poolAndVolumeCommonRules(vol *drivers.Volume) map[string]func(string) error {

This could be used for get/unset for pools/volumes

I also couldn't find a list of available storage drivers, but this is only needed for pool create.

[stgraber]

In general you can import from internal in the CLI but importing from internal/server sounds isn't ideal as there's a high chance that this imports a bunch more things and may pull cgo code too.

As we're getting most config keys to be exported to a json file for documentation purposes, I think it will make sense to have the CLI similarly either import the json data at build time or even take it one step further and directly fetch the list of valid config keys through the API.

[adamcstephens]

directly fetch the list of valid config keys through the API.

This sounds like a great idea to me. Does this API exist already?

There are a handful of key lists manually maintained in the old bash completion, and I'm doing my best to get parity (and then some) with the old completions. For an individual resource's config keys, I can just pull them from the resource.

Unfortunately, I've only found a nice list of all keys for instances here:

incus/internal/instance/config.go

Line 30 in cff35a2

var InstanceConfigKeysAny = map[string]func(value string) error{

It's also possible I'm missing something, and these lists exist for the other resources too. :)

[stgraber]

incus query /1.0/metadata/configuration shows you what's currently in there, though I need to clean that stuff up a bit because there's no matching Go client function for it apparently...

We should get a GetMetadataConfiguration() function to grab that data.

[adamcstephens]

Sounds good. This should still be ok to merge now, and I can add completions for the missing config keys once #600 is done.