[master] Define "__virtualname__" for transactional_update module

[meaksh]

What does this PR do?

On openSUSE MicroOS and SLE Micro, transactional systems, this prevent problems with "LazyLoader" when importing transactional_update module, which was wrongly exposing functions for this module under state.* on Salt >= 3005.

Previous Behavior

The following exception is triggered by salt minion when calling state.apply:

   The minion function caused an exception: Traceback (most recent call last):
      File "/usr/lib/python3.10/site-packages/salt/minion.py", line 1939, in _thread_return
        return_data = minion_instance._execute_job_function(
      File "/usr/lib/python3.10/site-packages/salt/minion.py", line 1898, in _execute_job_function
        return_data = self.executors[fname](opts, data, func, args, kwargs)
      File "/usr/lib/python3.10/site-packages/salt/loader/lazy.py", line 149, in __call__
        return self.loader.run(run_func, *args, **kwargs)
      File "/usr/lib/python3.10/site-packages/salt/loader/lazy.py", line 1230, in run
        return self._last_context.run(self._run_as, _func_or_method, *args, **kwargs)
      File "/usr/lib/python3.10/site-packages/salt/loader/lazy.py", line 1245, in _run_as
        return _func_or_method(*args, **kwargs)
      File "/usr/lib/python3.10/site-packages/salt/executors/transactional_update.py", line 123, in execute
        opts, data, __salt__[DELEGATION_MAP[fun]], args, kwargs
      File "/usr/lib/python3.10/site-packages/salt/loader/context.py", line 78, in __getitem__
        return self.value()[item]
      File "/usr/lib/python3.10/site-packages/salt/loader/lazy.py", line 336, in __getitem__
        super().__getitem__(item)  # try to get the item from the dictionary
      File "/usr/lib/python3.10/site-packages/salt/utils/lazy.py", line 105, in __getitem__
        raise KeyError(key)
    KeyError: 'transactional_update.apply'

New Behavior

The state.apply works as expected.

Merge requirements satisfied?

[NOTICE] Bug fixes or features added to Salt require tests.

• Docs
• Changelog - https://docs.saltproject.io/en/master/topics/development/changelog.html
• Tests written/updated

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[Ch3LL]

Is this error only showing up on openSUSE MicroOS and SLE Micro, transactional systems ? If so why is that the case?

I'm wondering if we can add test coverage here easily or not.

This will certainly need a changelog though.

[meaksh]

@Ch3LL sorry for the delay answering here.

Is this error only showing up on openSUSE MicroOS and SLE Micro, transactional systems ? If so why is that the case?

Yes, that is the case atm. The "transactional_update" execution module is only available on transactional systems, where transactional-update CLI is available.

I think this might have some relation with the usage of the "transactional_update" executor, which is configured by default in Salt configuration for transactional systems:

# Enable the transactional_update executor
module_executors:
  - transactional_update
  - direct_call

This executor [1], contains a set of modules and functions that must be executed via "transactional_update" module, as they are expected to make changes on the readonly system and therefore a new transaction/snapshot is required.

One of these function is state.apply of course. Other modules goes directly to direct_call, i.a. test.ping.

As mentioned, without defining this __virtualname__, and maybe because of this extra executor layer, the LazyLoader seems to mess (in Salt >= 3005) and functions from transactional_update execution module end up being exposed as state.*.

One note: the transactional_update executor module does import some things from salt.modules.state, and also import salt.client.ssh.state and salt.client.ssh.wrapper.state. Not sure if that could be confusing the LazyLoader mechanism.

I'm wondering if we can add test coverage here easily or not.

It doesn't seems straight forward, as it is not really clear yet what is triggering this behavior.

This will certainly need a changelog though.

I've added it now 👍

[1] https://github.com/saltstack/salt/blob/master/salt/executors/transactional_update.py