vagrant connector: `--limit` not used early enough and fail in `get_vagrant_config` of unavailble VMs

[paul-ri]

Describe the bug

With only 1 Vagrant VM existing and up, and an inventory referring to multiple Vagrant VMs by name, --limit is not applied early enough and the Vagrant config of non-existing VMs tries to be fetched but fails

I think the error starts from this line where the Vagrant connector tries to fetch a VM config before applying the limits

https://github.com/pyinfra-dev/pyinfra/blob/7540c41fa0284b8dd80dcbea24d3616414484d60/pyinfra/api/inventory.py#L101

My use case: well it's quite an edge case. I was trying something so replaced all our SSH targets with variations of @vagrant/XXX in order to be sure to not touch the real ones. I was trying to learn how --limit worked. Using mock @ssh/foo works fine as a workaround for me.

To Reproduce

Start one Vagrant VM. Have an inventory referring to two VMs where one doesn't exist yet, then apply a limit.

# inventory.py
prod_a = [
    "@vagrant/default",
]

prod_b = [
    "@vagrant/foo",
]

calling pyinfra with pyinfra inventory.py <some_operation> --limit prod_a will fail due to pyinfra trying to get the config info on prod_b anyways

Expected behavior

I would expect for pyinfra to handle the --limit argument and not try to make a connection to VMs not mentioned in --limit

Meta

• Include output of pyinfra --support.

> pyinfra --support
--> Support information:

    If you are having issues with pyinfra or wish to make feature requests, please
    check out the GitHub issues at https://github.com/Fizzadar/pyinfra/issues .
    When adding an issue, be sure to include the following:

    System: Linux
      Platform: Linux-6.5.9-arch2-1-x86_64-with-glibc2.38
      Release: 6.5.9-arch2-1
      Machine: x86_64
    pyinfra: v2.7
    Executable: /home/paul/git/<REDACTED>/.venv/bin/pyinfra
    Python: 3.11.2 (CPython, GCC 13.1.1 20230429)

• How was pyinfra installed (source/pip)? Pip

• Include pyinfra-debug.log (if one was created) empty

• Consider including output with -vv and --debug.

[Fizzadar]

Interesting bug, unfortunately the way connectors generate inventory means it will always try to load before we can apply a limit. But maybe we shouldn't be failing here at all and actually it should fail at connect time, since the VM config exists.

I'll need to do some testing with Vagrant for this.