limactl shell: ask whether to start the instance if not running

[AkihiroSuda]

Before

$ lima
FATA[0000] instance "default" does not exist, run `limactl create default` to create a new instance

After

$ lima
ERRO[0000] instance "default" does not exist, run `limactl create default` to create a new instance 
? Do you want to create and start the instance "default" using the default template now? Yes
? Creating an instance "default" Proceed with the current configuration
[...]
INFO[0114] READY.
suda@lima-default:/Users/suda/gopath/src/github.com/lima-vm/lima$

[afbjorklund]

I think the improvement of the "lima" command is good, but haven't looked at the code yet...

We might need something similar for the shell wrappers, like docker.lima and podman.lima?

instance "docker" does not exist, run `limactl create --name=docker template://docker` to create a new instance

instance "podman" does not exist, run `limactl create --name=podman template://podman` to create a new instance

The nerdctl.lima wrapper should be good, since it only calls lima (which calls limactl shell)

It could need some work, to get the same "user interface" in the bash script (as with survey)

[AkihiroSuda]

We might need something similar for the shell wrappers, like docker.lima and podman.lima?

Yes, but it is beyond the scope of this PR

[afbjorklund]

The current user experience is actually two steps, one to create and one to start:

$ lima
FATA[0000] instance "default" does not exist, run `limactl create default` to create a new instance 
$ limactl create default
? Creating an instance "default" Proceed with the current configuration
...
INFO[0003] Run `limactl start default` to start the instance. 

$ lima
FATA[0000] instance "default" is stopped, run `limactl start default` to start the instance 
$ limactl start default
...
INFO[0068] READY. Run `lima` to open the shell.         

Or maybe three steps, considering that you still have to run the original lima command again?

So it's a good thing reducing 3 to 1.

[afbjorklund]

Yes, but it is beyond the scope of this PR

Didn't find any issue for the entire change.

[AkihiroSuda]

What should we do with this?
@lima-vm/maintainers

[jandubois]

What should we do with this?

I'll try to take a look soon. I hope we can get this into 1.0.

[jandubois]

Sorry, this isn't a complete review, but I think the mandatory logic is not working correctly (it shows error messages multiple times).

I'm suggesting an alternative, but I'm not totally sure if it will work; I would need to try it myself. Let me know if you want me to make an attempt!

[jandubois]

It is not clear what the bool return value represents. It also seems to be completely unused; all 3 call-sites are _, err = startInteractive(…).

[jandubois]

rootCmd could be setup outside the conditional because it is needed again later.

[jandubois]

I would have expected that the template would default to the instance name, if a template existed with that name. Otherwise it should show an error and only then default to default.

$ l shell alpine
ERRO[0000] instance "alpine" does not exist, run `limactl create alpine` to create a new instance
? Do you want to create and start the instance "alpine" using the default template now?

This should say "using the alpine template".

[jandubois]

I agree that the mandatory mechanism is too complex/confusing. It also results in the same error being displayed twice, first as ERRO and then as FATA:

$ l shell alpine
ERRO[0000] instance "alpine" does not exist, run `limactl create alpine` to create a new instance
? Do you want to create and start the instance "alpine" using the default template now? No
FATA[0002] instance "alpine" does not exist, run `limactl create alpine` to create a new instance

I think the mandatory argument can just be removed, and the function always just returns nil when the user elected not to create/start the instance.

The caller is already calling store.Inspect() afterwards, and can then simply exit if the instance isn't in running state.

[jandubois]

Let me know if you want me to make an attempt!

Ok, I went ahead and created #2832, which I think is simpler to follow. LMK what you think!