Support incremental builds for containers

[sansmoraxz]

Proposal

Use the build cache from GOCACHE while building container images.

Use-Case

Currently it takes quite a long time to build the images. Although using vendor bypasses having to pull the packages from remote, the bulk of the time is spent on compiling the codebase. Having the build cache mounted from host machine would significantly improve the build time (especially rebuilds after making slight changes to codebase).

Is this a feature you are interested in implementing yourself?

Yes

Anything else?

Alternatively we could bind the entire go env GOCACHE from the host system while building. But this could have a lot of edge cases with different OS and architectures, viz. would be relatively tough to pull off with windows as they use different file systems.