Allows the clients to remain connected and be none the wiser that there was an update at all.
For larger updates we just do hard restarts when in-memory data structures or supervision tree are changed.
* The server runs in a docker container which has an ssh server installed and running in the background. The reason for SSH is simply because that's what edeliver/distillery uses.
* The CI(local github runner) runs in a docker container as well which handles building and deploying the updated releases when merged on master.
* We use edeliver to deploy the hot upgrades/releases from the CI container to the server container. This happens automatically unless stopped which we do for larger merges where a restart is needed.
* The whole deployment process is done in a bash script which uses the git hash for versioning, edeliver for deploying and in the end it runs the database migrations.
I'm not going to say it's perfect but it's allowed us to move pretty damn fast.