Make devcontainer opt-in when creating a new application

For Rails 7.2 we will make devcontainer and opt-in feature for new applications. When creating a new app, you can generate a devcontainer by passing the --devcontainer flag.

.github/workflows/devcontainer-smoke-test.yml

@@ -31,7 +31,7 @@ jobs:
           bundler-cache: true
 
       - name: Generate rails app sqlite3
-        run: bundle exec railties/exe/rails new myapp_sqlite --database="sqlite3" --dev
+        run: bundle exec railties/exe/rails new myapp_sqlite --database="sqlite3" --dev --devcontainer
 
       - name: Remove old deprecated docker-compose
         run: |
@@ -52,7 +52,7 @@ jobs:
         run: docker ps -q | xargs docker stop
 
       - name: Generate rails app postgresql
-        run: bundle exec railties/exe/rails new myapp_postgresql --database="postgresql" --dev
+        run: bundle exec railties/exe/rails new myapp_postgresql --database="postgresql" --dev --devcontainer
 
       - name: Test devcontainer postgresql
         uses: devcontainers/ci@v0.3
@@ -69,7 +69,7 @@ jobs:
         run: docker ps -q | xargs docker stop
 
       - name: Generate rails app mysql
-        run: bundle exec railties/exe/rails new myapp_mysql --database="mysql" --dev
+        run: bundle exec railties/exe/rails new myapp_mysql --database="mysql" --dev --devcontainer
 
       - name: Test devcontainer mysql
         uses: devcontainers/ci@v0.3
@@ -86,7 +86,7 @@ jobs:
         run: docker ps -q | xargs docker stop
 
       - name: Generate rails app trilogy
-        run: bundle exec railties/exe/rails new myapp_trilogy --database="trilogy" --dev
+        run: bundle exec railties/exe/rails new myapp_trilogy --database="trilogy" --dev --devcontainer
 
       - name: Test devcontainer trilogy
         uses: devcontainers/ci@v0.3

guides/source/command_line.md

@@ -67,7 +67,6 @@ If you wish to skip some files from being generated or skip some libraries, you
 | `--skip-bootsnap`       | Skip bootsnap gem                                        |
 | `--skip-dev-gems`       | Skip adding development gems                             |
 | `--skip-rubocop`        | Skip RuboCop setup                                       |
-| `--skip-devcontainer`   | Skip Dev Container setup                                 |
 
 These are just some of the options that `rails new` accepts. For a full list of options, type `rails new --help`.
 

guides/source/getting_started.md

@@ -198,7 +198,6 @@ of the files and folders that Rails creates by default:
 |.gitignore|This file tells git which files (or patterns) it should ignore. See [GitHub - Ignoring files](https://help.github.com/articles/ignoring-files) for more information about ignoring files.|
 |.rubocop.yml|This file contains the configuration for RuboCop.|
 |.ruby-version|This file contains the default Ruby version.|
-|.devcontainer/|This folder contains the Dev Container configuration|
 
 Hello, Rails!
 -------------

railties/lib/rails/generators/app_base.rb

@@ -109,15 +109,15 @@ module Rails
         class_option :skip_ci,             type: :boolean, default: nil,
                                            desc: "Skip GitHub CI files"
 
-        class_option :skip_devcontainer,   type: :boolean, default: false,
-                                           desc: "Skip devcontainer files"
-
         class_option :skip_kamal,          type: :boolean, default: false,
                                            desc: "Skip Kamal setup"
 
         class_option :dev,                 type: :boolean, default: nil,
                                            desc: "Set up the #{name} with Gemfile pointing to your Rails checkout"
 
+        class_option :devcontainer,        type: :boolean, default: false,
+                                           desc: "Generate devcontainer files"
+
         class_option :edge,                type: :boolean, default: nil,
                                            desc: "Set up the #{name} with a Gemfile pointing to the #{edge_branch} branch on the Rails repository"
 
@@ -411,7 +411,7 @@ module Rails
       end
 
       def skip_devcontainer?
-        options[:skip_devcontainer]
+        !options[:devcontainer]
       end
 
       def skip_kamal?

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 } %>
-<% unless options[:skip_devcontainer] -%>
+<% if options[:devcontainer] -%>
   <%% if ENV["DB_HOST"] %>
   host: <%%= ENV["DB_HOST"] %>
   username: postgres

railties/test/generators/app_generator_test.rb

@@ -5,9 +5,6 @@ require "rails/generators/rails/app/app_generator"
 require "generators/shared_generator_tests"
 
 DEFAULT_APP_FILES = %w(
-  .devcontainer/Dockerfile
-  .devcontainer/compose.yaml
-  .devcontainer/devcontainer.json
   .dockerignore
   .git
   .gitattributes
@@ -1050,9 +1047,6 @@ class AppGeneratorTest < Rails::Generators::TestCase
 
     ruby_version = "#{Gem::Version.new(Gem::VERSION) >= Gem::Version.new("3.3.13") ? Gem.ruby_version : RUBY_VERSION}"
 
-    assert_file ".devcontainer/Dockerfile" do |content|
-      assert_match(/ARG RUBY_VERSION=#{ruby_version}$/, content)
-    end
     assert_file "Dockerfile" do |content|
       assert_match(/ARG RUBY_VERSION=#{ruby_version}/, content)
     end
@@ -1275,7 +1269,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_devcontainer
-    run_generator [destination_root, "--name=my-app"]
+    run_generator [destination_root, "--devcontainer", "--name=my-app"]
 
     assert_devcontainer_json_file do |content|
       assert_equal "my_app", content["name"]
@@ -1329,7 +1323,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_devcontainer_no_redis_skipping_action_cable_and_active_job
-    run_generator [ destination_root, "--skip-action-cable", "--skip-active-job" ]
+    run_generator [ destination_root, "--devcontainer", "--skip-action-cable", "--skip-active-job" ]
 
     assert_compose_file do |compose_config|
       assert_not_includes compose_config["services"]["rails-app"]["depends_on"], "redis"
@@ -1343,7 +1337,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_devcontainer_postgresql
-    run_generator [ destination_root, "-d", "postgresql" ]
+    run_generator [ destination_root, "--devcontainer", "-d", "postgresql" ]
 
     assert_compose_file do |compose_config|
       assert_includes compose_config["services"]["rails-app"]["depends_on"], "postgres"
@@ -1373,7 +1367,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_devcontainer_mysql
-    run_generator [ destination_root, "-d", "mysql" ]
+    run_generator [ destination_root, "--devcontainer", "-d", "mysql" ]
 
     assert_compose_file do |compose_config|
       assert_includes compose_config["services"]["rails-app"]["depends_on"], "mysql"
@@ -1403,7 +1397,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_devcontainer_mariadb
-    run_generator [ destination_root, "-d", "trilogy" ]
+    run_generator [ destination_root, "--devcontainer", "-d", "trilogy" ]
 
     assert_compose_file do |compose_config|
       assert_includes compose_config["services"]["rails-app"]["depends_on"], "mariadb"
@@ -1430,7 +1424,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_devcontainer_no_selenium_when_skipping_system_test
-    run_generator [ destination_root, "--skip-system-test" ]
+    run_generator [ destination_root, "--devcontainer", "--skip-system-test" ]
 
     assert_compose_file do |compose_config|
       assert_not_includes compose_config["services"]["rails-app"]["depends_on"], "selenium"
@@ -1442,7 +1436,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_devcontainer_no_feature_when_skipping_active_storage
-    run_generator [ destination_root, "--skip-active-storage" ]
+    run_generator [ destination_root, "--devcontainer", "--skip-active-storage" ]
 
     assert_devcontainer_json_file do |content|
       assert_nil content["features"]["ghcr.io/rails/devcontainer/features/activestorage"]
@@ -1450,7 +1444,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_devcontainer_no_depends_on_when_no_dependencies
-    run_generator [ destination_root, "--minimal" ]
+    run_generator [ destination_root, "--devcontainer", "--minimal" ]
 
     assert_compose_file do |compose_config|
       assert_not_includes compose_config["services"]["rails-app"].keys, "depends_on"
@@ -1458,7 +1452,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_devcontainer_adds_node_tooling_when_required
-    run_generator [destination_root, "--javascript=esbuild"]
+    run_generator [destination_root, "--devcontainer", "--javascript=esbuild"]
 
     assert_devcontainer_json_file do |devcontainer_config|
       assert_includes devcontainer_config["features"].keys, "ghcr.io/devcontainers/features/node:1"
@@ -1466,7 +1460,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_devcontainer_does_not_add_node_tooling_when_not_required
-    run_generator [destination_root]
+    run_generator [destination_root, "--devcontainer"]
 
     assert_devcontainer_json_file do |devcontainer_config|
       assert_not_includes devcontainer_config["features"].keys, "ghcr.io/devcontainers/features/node:1"
@@ -1474,7 +1468,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
   end
 
   def test_devcontainer_dev_flag_mounts_local_rails_repo
-    run_generator_using_prerelease [ destination_root, "--dev" ]
+    run_generator_using_prerelease [ destination_root, "--devcontainer", "--dev" ]
 
     assert_devcontainer_json_file do |devcontainer_config|
       rails_mount = devcontainer_config["mounts"].sole
@@ -1485,8 +1479,8 @@ class AppGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  def test_skip_devcontainer
-    run_generator [ destination_root, "--skip-devcontainer" ]
+  def test_no_devcontainer_by_default
+    run_generator [ destination_root ]
 
     assert_no_file(".devcontainer/devcontainer.json")
     assert_no_file(".devcontainer/Dockerfile")