Modify volume mount behavior when source does not exist

[demonpig]

ansible-runner will ignore adding the mountpoint to the '-v` argument list if the source path does not exist. Instead it should respect whatever the user is passing to the '--container-volume-mount' option. The exception would be if the user tried to pass a file as the source path; ansible-runner should resolve the file's parent directory.

[demonpig]

I'm not entirely sure what to do about the failing unit tests. Please advise.

[Shrews]

I had to research this behavior a bit, but it appears that docker and podman handle these cases differently, which is curious to me since I thought they tried to mostly be 1-to-1 compatible.

• The docker run help page indicates that when the source volume mount does not exist, it will be created for you.
• On the other hand, the podman run help page indicates that podman will throw an error when the source volume does not exist and users "must pre-create the source files or directories".

Given the differing behavior, I'm not in favor of this change as it is since it would suddenly cause users who may be using podman to get unexpected errors during a different/later phase of ansible-runner. If you were to modify the change to consider which container engine is in use (i.e., ignore the existence check if using docker), I'd be more in favor of it. This also might clear up some of the unit test failures, but likely not all of them.

[Shrews]

@demonpig After some discussion with others around this, I'm starting to come around to the idea of just keeping this as-is and letting the container engine do whatever it's going to do. I haven't had a chance to explore your unit test failures, but you should check how your changes affect the output that is expected when comparing the generated run command.

[demonpig]

@Shrews Thanks for the updates. I'll take a look at them and see what I can do to fix them.