Add Check How Database Is Configured as a Rails TIL

rails/check-how-database-is-configured.md

@@ -0,0 +1,46 @@
+# Check How Database Is Configured
+
+While making some adjustments to the database connection string (`DATABASE_URL`)
+for a pre-production Rails environment, we wanted to check that configuration
+options like `sslmode` were picked up.
+
+From a `rails console` session I can check the live database configuration like
+so:
+
+```ruby
+> ActiveRecord::Base.connection_db_config.configuration_hash
+=> {
+  adapter: "postgresql",
+  encoding: "unicode",
+  pool: 5,
+  database: "my_app_development"
+}
+```
+
+I can look at the
+[`configuration_hash`](https://api.rubyonrails.org/classes/ActiveRecord/DatabaseConfigurations/HashConfig.html#attribute-i-configuration_hash)
+from `rails console` of my pre-prod environment to see more configuration
+settings:
+
+```ruby
+> ActiveRecord::Base.connection_db_config.configuration_hash
+=> {
+  adapter: "postgresql",
+  encoding: "unicode",
+  pool: 5,
+  username: "app_user",
+  password: "super_s3cr3t",
+  port: 15432,
+  database: "pre_prod_database",
+  host: "some-host-123.ondigitalocean.com",
+  sslmode: "verify-full"
+}
+```
+
+Since I was specifically looking for the `sslmode` value, I can access that
+directly:
+
+```ruby
+> ActiveRecord::Base.connection_db_config.configuration_hash[:sslmode]
+=> "verify-full"
+```