Document the SOPS setup for encrypting secrets in repo

Problem

#200 introduced the need to store secrets in git. We used SOPS with hashicorp vault to implement it. This fact and the required workflows are undocumented yet.

TODO: WHY do we need this?

Goal

Document how the SOPS setup works.

ACs

  • The infra repo contains docs about the used setup to store encrypted secrets in repo and guidance how to use it

Notes/ resources

cf. https://matrix.to/#/!ethZaECJGUnNhVlNKA:element.io/$sQAc6Uq9fyAHwkYscLXWn1zmcTjere0Cw554fMpxzW4?via=element.io&via=matrix.org&via=nordeck.io ff.

Hashicorp vault is not open-source any more. Is this okay for us? What are the implications thereof?

There is a vault deployed at https://vault.infra.dev.neo.fitko.dev/ui

Who needs to be involved / informed

  • reviewers:
  • involved: team::infra-and-ops, Yan, Ben?
  • informed:
Edited by Marco Holz