Rust seed application

It's written in Rust!

This is a framework for building Rust applications in combination with building Docker containers and never rebuilding code on release, instead we promote existing code.

TODO and done

• Figure out how to deal with PRs pushing too many Docker containers
  

  We only build containers on the tip of the PR, so even if you're pushing 10 commits, we'll only build one.

• Remove old containers when the new one gets build for a PR?
  Or rely on a general weekly untagged cleanup?
• Remove PR containers when PR closed
  

  API currently unavailable

• How do we deal with older containers on main?
  

  We move tags, so we'll need to wait for the API to clean up untagged versions