exposing container id and image id to the occupants of executing environments

[lpgc]

the container id and its associated image id are crucial identifiers to processes executing within such environments; applications and services themselves may want to include such information in their logging, and r/t environments such as the Java Virtual Machine may wish to utilize such identifiers in order to disambiguate themselves with their peer containers when accessing shared resources.

The runtime spec should define a standard mechanism for processes deployed therein to obtain these identifiers.

[tianon]

Unfortunately, these identifiers don't exist at the level of the runtime-spec - they're all higher-level abstractions. See also (your 😂 😅) #1105, which has a lot of very related discussion.

(I'm going to close this as a duplicate of #1105 ❤️)