adaptation: support concurrent RPCs via per Pod lock

[jipperinbham]

For users who do not need to perform cross Pod updates, a new per Pod lock implementation can be selected via WithPodLocking() Option func. These changes would need to go along with a similar containerd change as containerd/containerd#11671 to both expose the ability to select the per pod locker as well as remove the global lock on each nri RPC invocation in containerd.

Addresses #165

[jipperinbham]

@klihub Any chance you can take a look at this and provide some feedback?

[klihub]

@klihub Any chance you can take a look at this and provide some feedback?

I'll take a closer look.

[klihub]

I think this would be problematic as it would implicitly divide plugins into two classes, those which could run correctly with this configuration and those which could not. The runtime would need to be configured accordingly, locking potentially out some plugins or risk them to work incorrectly. So I'll try to find some time to experiment a bit with a possible solution I had in mind and see if I could come up with something tangible enough proto to play a bit around with in practice.

[jipperinbham]

I think this would be problematic as it would implicitly divide plugins into two classes, those which could run correctly with this configuration and those which could not. The runtime would need to be configured accordingly, locking potentially out some plugins or risk them to work incorrectly. So I'll try to find some time to experiment a bit with a possible solution I had in mind and see if I could come up with something tangible enough proto to play a bit around with in practice.

Thanks for taking the time to review and consider the tradeoffs which makes sense given the wider scope of plugin authors/users outside of our specific needs.