How would I store a Redis subscription inside a GenServer?

[seivan]

Let’s say I want to make a lobby that’s distributed across nodes and I don’t want to rely on hydras distributed networking yet. Mostly because I want the state to be external in case server updates occur and I don’t want to manage state handovers like Elixir and libcluster.

So my approach is dynamically started Supervisor that starts another GenServer that works as a lobby. It gets messages that a player has joined/left/sent a message.

The GenServer would then subscribe to a Redis channel.

When a user joins/leaves/sends a message it would publish it to all connected users (graphql subscription) but also to the Redis pubsub and the other gen-server would do the same.

I guess what I’m asking is how can a GenServer hold a Redis subscription? And how can I return a Stream for something like a async-graphql subscription?