Docker support

[Chvx]

The goal of the changes is to migrate towards a clean containerized infrastructure. They add support for:

• building Docker images in two flavours:

  • runtime: the image used to run the application
  • unittest: the image used to run unit tests

• new environment variable REDIS_SKIP_TLS_CHECK used to skip TLS even in production settings for the Docker stack (targetting a local container via the Docker internal network, no need for TLS).

• Github actions:

  • build the runtime image (tagged prerelease) on a merge to main, publishes the image to Github container repository, and triggers a refresh of the prerelease environment to use the new image
  • build the unit test image on a PR or merge to main, and immediately start it to run the tests
  • a manual action to retag the prerelease image as production and latest, preparing for a deployment to production

The application can still be built and run outside of a container environment.