SPI for ContainerProxy

Hi!

I am currently looking for a way to run some custom code whenever a container is provisioned with an actual action in Adobe I/O Runtime (both for stem cells and completely new containers). We are providing some extra services as part of our platform that need to be configured with some action-specific data which are however not part of the action itself.

In order to achieve this I would like to SPI ContainerProxy; we could simply subclass it, intercepting the state transitions…
I'd be happy to implement the SPI, but I would like to get some feedback from the openwhisk community as this would be the first openwhisk feature I am working on…

Alternatively it would be possible to implement some sort of Event listening scheme, although I do not think that would fit very well into the existing Openwhisk code base?

Thanks for your great work on openwhisk!

Start by reading ContainerProxy and the code that handles its state transitions and container provisioning. Clarify with the OpenWhisk community whether an SPI or event-listening scheme is preferred, then define what support for custom action-specific configuration must cover for both stem cells and new containers.

Written by the indexing model from the issue text.