Configuring Solid Cable on Render

Rails 8 added a lot of new features. Solid Cable comes as a drop in replacement to Action Cable and, by default, it uses the database instead of requiring Redis.

I generated a new app (with Postgres), added some tables and turbo streams and then deployed to Render. The deployment failed!

Exited with status 1 while building your code.

This error message wasn’t very clear! But the line of code pointed to a broadcasts_to in my Comment model, so I was pretty sure it was Solid Cable related.

after_create_commit -> { broadcast_before_to "...", target: "...", partial: "..." }

I learned that Solid Cable runs in a separate database, which I assume Render didn’t like. I followed the instructions in the Solid Cable README to configure Solid Cable to work with a single database and I was able to deploy to Render!

1. Copy the contents of db/cable_schema.rb into a normal migration and delete db/cable_schema.rb
2. Remove connects_to from config/cable.yml
3. bin/rails db:migrate

🎉