Serving: Document container runtime contract

[evankanderson]

Expected Behavior

Developers and runtime contributors can understand and identify issues with their application which may prevent the container from working properly in the Elafros environment.

Actual Behavior

Invoke nasal daemon. More practically, standardizing processes like log collection, inbound and outbound traffic profiles (HTTP inbound, outbound DNS, etc) will make it easier to ensure that containers are portable between environments, or that the differences between environments can be cataloged and documented.

Additional Info

Expected process:

1. Draft a Google doc extending some common spec (suggest OCI)
2. Collect comment in doc from various users as to applications / libraries / languages this would break or inconvenience.
3. Close out comments on doc, convert to markdown, and create a PR
4. Commit PR and close out this issue.

[grantr]

TIL about nasal demons

[evankanderson]

Initial draft:

https://docs.google.com/document/d/1_LFb928iMhILpma7XmF_2SyRrZ5C2ynDietf12a7uO8/edit#

I expect that we'll let this sit at least a week with so many people at kubecon.