Update README.md

README.md

@@ -75,6 +75,32 @@ docker-compose run web rails new . --force --database=postgresql
 docker-compose up
 ```
 
+* Edit ``config/database.yml``
+
+```bash
+default: &default
+  adapter: postgresql
+  encoding: unicode
+  host: db
+  username: <%= ENV['POSTGRES_USER'] %>
+  password: <%= ENV['POSTGRES_PASSWORD'] %>
+  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
+
+development:
+  <<: *default
+  database: <%= "#{ENV['DATABASE_NAME']}_development" %>
+
+test:
+  <<: *default
+  database: <%= "#{ENV['DATABASE_NAME']}_test" %>
+
+production:
+  <<: *default
+  database: app_production
+  username: app
+  password: <%= ENV['RAILS_DATABASE_PASSWORD'] %>
+```
+
 * Create the ``development`` and ``test`` database
 
 ```bash