[Feature][DX] Add Docker Configuration for Development

CHANGELOG.md

@@ -3,6 +3,7 @@
 * Provide a 'Changelog' link on Rubygems: https://github.com/DatabaseCleaner/database_cleaner-active_record/pull/114
 * Fix bundling and CONTRIBUTE.md instructions: https://github.com/DatabaseCleaner/database_cleaner-active_record/pull/123
 * Fix order of arguments in `truncate_tables` expectation https://github.com/DatabaseCleaner/database_cleaner-active_record/pull/124
+* Add Docker to make it easier to run tests locally for maintainers and contributors https://github.com/DatabaseCleaner/database_cleaner-active_record/pull/109
 
 ## v2.2.1 2025-05-13
 

CONTRIBUTE.md

@@ -12,15 +12,28 @@ upstream:
 
 The gem uses Appraisal to configure different Gemfiles to test different Rails versions.
 
-- You can run all the databases through docker if needed with `docker compose up` (you can also have them running on your system, just comment out the ones you don't need from the `docker-compose.yml` file)
-- Copy `spec/support/sample.config.yml` to `spec/support/config.yml` and edit it
+### Run tests without Docker (or using Docker only for the databases)
+
+- You can run all the databases through docker if needed with `docker compose -f docker-compose.db.yml up` (you can also have them running on your system, just comment out the ones you don't need from the `docker-compose.db.yml` file)
+- Copy `spec/support/sample.config.yml` to `spec/support/config.yml` and edit it as needed
 - `BUNDLE_GEMFILE=gemfiles/rails_6.1.gemfile bundle install` (change `6.1` with any version from the `gemfiles` directory)
 - `BUNDLE_GEMFILE=gemfiles/rails_6.1.gemfile bundle exec rake`
 
 Note that if you don't have all the supported databases installed and running,
 some tests will fail.
 
-> Note that you can check the `.github/workflows/ci.yml` file for different combinations of Ruby and Rails that are expected to work
+> Check the `.github/workflows/ci.yml` file for different combinations of Ruby and Rails that are expected to work
+
+### Run tests with Docker
+
+- Open `docker-compose.yml` and configure the Ruby version and Gemfile file to use
+- Copy `spec/support/sample.docker.config.yml` to `spec/support/config.yml` (not this config file is specific for the Docker setup)
+- Run `docker compose up` to start the container, run the tests, and exit
+- Run `docker compose run ruby bash` to open `bash` inside the container for more control, run `rake` to run the tests
+
+> Note that the code is mounted inside the docker container, so changes in the container will reflect in the code. There's no need to re-build the container for code changes, but changing the Ruby version or Gemfile in the docker-compose.yml will require a container re-build with `docker compose build --no-cache`
+
+> Check the `.github/workflows/ci.yml` file for different combinations of Ruby and Rails that are expected to work
 
 ## 3. Prepare your contribution
 

Dockerfile

@@ -0,0 +1,19 @@
+ARG RUBY_VERSION=3.3
+FROM ruby:${RUBY_VERSION}
+
+# Set the working directory in the container
+WORKDIR /app
+
+# Copy the current directory contents into the container at /app
+# This is copied so we can bundle the application, but it's replaced
+# by a mounted volume with the current code when executed with docker compose
+COPY . /app
+
+ARG BUNDLE_GEMFILE=Gemfile
+ENV BUNDLE_GEMFILE=${BUNDLE_GEMFILE}
+
+# Install any needed packages specified in Gemfile
+RUN ./bin/setup
+
+# Command to run the application
+CMD ["bash"]

README.md

@@ -102,6 +102,10 @@ test:
   min_messages: WARNING
 </pre>
 
+## Development
+
+Check the CONTRIBUTE.md file for instructions running tests with and withour Docker.
+
 ## COPYRIGHT
 
 See [LICENSE](LICENSE) for details.

database_cleaner-active_record.gemspec

@@ -18,7 +18,7 @@ Gem::Specification.new do |spec|
   spec.executables   = []
   spec.require_paths = ["lib"]
 
-  spec.add_dependency "database_cleaner-core", "~>2.1.0"
+  spec.add_dependency "database_cleaner-core", "~>2.0"
   spec.add_dependency "activerecord", ">= 5.a"
 
   spec.add_development_dependency "bundler"

docker-compose.db.yml

@@ -0,0 +1,19 @@
+services:
+  postgres:
+    image: postgres:16 # specify the version needed for a given app
+    environment:
+      - POSTGRES_PASSWORD=postgres # this is required
+    ports:
+      - "127.0.0.1:5432:5432" # so we can use `localhost` as the host
+  mysql:
+    image: mysql:5.7
+    environment:
+      - MYSQL_ROOT_PASSWORD=mysql
+    ports:
+      - "127.0.0.1:3306:3306"
+  redis:
+    image: redis:6.2-alpine
+    restart: always
+    ports:
+      - "127.0.0.1:6379:6379"
+    command: redis-server --save 20 1 --loglevel warning

docker-compose.yml

@@ -3,17 +3,24 @@ services:
     image: postgres:16 # specify the version needed for a given app
     environment:
       - POSTGRES_PASSWORD=postgres # this is required
-    ports:
-      - "127.0.0.1:5432:5432" # so we can use `localhost` as the host
   mysql:
-    image: mysql:9.3
+    image: mysql:5.7
     environment:
       - MYSQL_ROOT_PASSWORD=mysql
-    ports:
-      - "127.0.0.1:3306:3306"
   redis:
     image: redis:6.2-alpine
     restart: always
-    ports:
-      - "127.0.0.1:6379:6379"
     command: redis-server --save 20 1 --loglevel warning
+  ruby:
+    build:
+      context: .
+      args:
+        BUNDLE_GEMFILE: gemfiles/rails_7.2.gemfile # Manually change this based on the desired Rails version
+        RUBY_VERSION: 3.3 # Manually change this based on the desired Ruby version
+    volumes:
+      - ".:/app:delegated"
+    command: rake
+    depends_on:
+      - mysql
+      - postgres
+      - redis

spec/support/sample.docker.config.yml

@@ -0,0 +1,33 @@
+mysql2:
+  adapter: mysql2
+  database: database_cleaner_test
+  username: root
+  password: mysql
+  host: mysql
+  port: 3306
+  encoding: utf8
+
+trilogy:
+  adapter: trilogy
+  database: database_cleaner_test
+  username: root
+  password: mysql
+  host: mysql
+  port: 3306
+  encoding: utf8
+
+postgres:
+  adapter: postgresql
+  database: database_cleaner_test
+  username: postgres
+  password: postgres
+  host: postgres
+  encoding: unicode
+  template: template0
+
+sqlite3:
+  adapter: sqlite3
+  database: tmp/database_cleaner_test.sqlite3
+  pool: 5
+  timeout: 5000
+  encoding: utf8