Add Solid Cable adapter for ActionCable

Switching the adapter is not expected to make any noticeable difference and is in line with CodeOcean. The new Solid Cable adapter is also shipping with Rails 8 by default.

.rubocop.yml

@@ -23,7 +23,7 @@ AllCops:
   NewCops: enable
   Exclude:
     - 'bin/*'
-    - 'db/schema.rb'
+    - 'db/*schema.rb'
     - 'vendor/**/*'
     # Ignore local files for faster processing
     - 'tmp/**/*'

Gemfile

@@ -41,6 +41,7 @@ gem 'sassc-rails'
 gem 'shakapacker', '8.0.2'
 gem 'simple_form'
 gem 'slim-rails'
+gem 'solid_cable'
 gem 'solid_queue'
 gem 'sprockets-rails'
 gem 'terser', require: false

Gemfile.lock

@@ -526,6 +526,8 @@ GEM
       rexml (~> 3.2)
       rubocop (>= 1.0, < 2.0)
       slim (>= 3.0, < 6.0)
+    solid_cable (2.0.2)
+      rails (>= 7.2)
     solid_queue (0.7.1)
       activejob (>= 7.1)
       activerecord (>= 7.1)
@@ -666,6 +668,7 @@ DEPENDENCIES
   simplecov
   slim-rails
   slim_lint
+  solid_cable
   solid_queue
   sprockets-rails
   stackprof

config/cable.yml

@@ -1,11 +1,24 @@
+default: &default
+  adapter: solid_cable # OR postgresql OR redis
+
+  ### Config options for `solid_cable`
+  connects_to:
+    database:
+      writing: cable
+  polling_interval: 0.1.seconds
+  message_retention: 1.day
+  autotrim: true
+  silence_polling: true
+
+  ### Config options for `redis`
+  # url: <%= ENV.fetch("REDIS_URL") { "redis://localhost:6379/1" } %>
+  # channel_prefix: codeharbor_production
+
 development:
-  adapter: postgresql
+  <<: *default
 
 test:
   adapter: test
 
 production:
-  adapter: postgresql # redis
-  # all other options below are only used for redis
-  # url: <%= ENV.fetch("REDIS_URL") { "redis://localhost:6379/1" } %>
-  # channel_prefix: codeharbor_production
+  <<: *default

config/database.yml.example

@@ -29,8 +29,13 @@ default: &default
   <% end %>
 
 development:
-  <<: *default
-  database: codeharbor_development
+  primary: &primary_development
+    <<: *default
+    database: codeharbor_development
+  cable:
+    <<: *primary_development
+    database: codeharbor_development_cable
+    migrations_paths: db/cable_migrate
 
 # Warning: The database defined as "test" will be erased and
 # re-generated from your development database when you run "rake".
@@ -56,5 +61,10 @@ test:
 # for a full overview on how database connection configuration can be specified.
 #
 production:
-  <<: *default
-  database: codeharbor_production
+  primary: &primary_production
+    <<: *default
+    database: codeharbor_production
+  cable:
+    <<: *primary_production
+    database: codeharbor_production_cable
+    migrations_paths: db/cable_migrate