Update database.yml from DevcontainerGenerator

Postgresql's database.yml has devcontainer specific logic that should only appear when the app has a devcontainer. We need the DevcontainerGenerator to update database.yml, so when it is called by the devcontainer command the database.yml will have the right configuration.

This commit also fixes db:system:change to make sure it updates the database.yml with the correct devcontainer configuration.

Author: andrewn617

railties/lib/rails/generators/app_base.rb

@@ -413,6 +413,10 @@ def skip_devcontainer?
         !options[:devcontainer]
       end
 
+      def devcontainer?
+        options[:devcontainer]
+      end
+
       def skip_kamal?
         options[:skip_kamal]
       end

railties/lib/rails/generators/rails/app/templates/config/databases/postgresql.yml.tt

@@ -18,7 +18,7 @@ default: &default
   # For details on connection pooling, see Rails configuration guide
   # https://guides.rubyonrails.org/configuring.html#database-pooling
   pool: <%%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
-<% if options[:devcontainer] -%>
+<% if devcontainer? -%>
   <%% if ENV["DB_HOST"] %>
   host: <%%= ENV["DB_HOST"] %>
   username: postgres

railties/lib/rails/generators/rails/db/system/change/change_generator.rb

@@ -53,8 +53,7 @@ def edit_dockerfile
           end
 
           def edit_devcontainer_files
-            devcontainer_path = File.expand_path(".devcontainer", destination_root)
-            return unless File.exist?(devcontainer_path)
+            return unless devcontainer?
 
             edit_devcontainer_json
             edit_compose_yaml
@@ -194,6 +193,12 @@ def devcontainer_json_path
             def database
               @database ||= Database.build(options[:database])
             end
+
+            def devcontainer?
+              return @devcontainer if defined?(@devcontainer)
+
+              @devcontainer = File.exist?(File.expand_path(".devcontainer", destination_root))
+            end
         end
       end
     end

railties/lib/rails/generators/rails/devcontainer/devcontainer_generator.rb

@@ -26,6 +26,8 @@ class DevcontainerGenerator < Base # :nodoc:
       class_option :dev, type: :boolean, default: false,
                     desc: "For applications pointing to a local Rails checkout"
 
+      source_paths << File.expand_path(File.join(base_name, "app", "templates"), base_root)
+
       def create_devcontainer
         empty_directory ".devcontainer"
 
@@ -41,7 +43,22 @@ def update_application_system_test_case
         gsub_file("test/application_system_test_case.rb", /^(\s*driven_by\b.*)/, system_test_configuration)
       end
 
+      def update_database_yml
+        # Only postgresql has devcontainer specific configuration, so only update database.yml if we are using postgres
+        return unless options[:database] == "postgresql"
+
+        template("config/databases/#{options[:database]}.yml", "config/database.yml")
+      end
+
       private
+        def devcontainer?
+          true
+        end
+
+        def app_name
+          options[:app_name]
+        end
+
         def dependencies
           return @dependencies if @dependencies
 

railties/test/generators/db_system_change_generator_test.rb

@@ -38,6 +38,7 @@ class ChangeGeneratorTest < Rails::Generators::TestCase
             assert_file("config/database.yml") do |content|
               assert_match "adapter: postgresql", content
               assert_match "database: tmp_production", content
+              assert_match "host: <%= ENV[\"DB_HOST\"] %>", content
             end
 
             assert_file("Gemfile") do |content|