Add sample using Docker Compose

doma-spring-boot-samples/doma-spring-boot-sample-docker-compose/HELP.md

@@ -0,0 +1,33 @@
+# Getting Started
+
+### Reference Documentation
+For further reference, please consider the following sections:
+
+* [Official Apache Maven documentation](https://maven.apache.org/guides/index.html)
+* [Spring Boot Maven Plugin Reference Guide](https://docs.spring.io/spring-boot/3.4.5/maven-plugin)
+* [Create an OCI image](https://docs.spring.io/spring-boot/3.4.5/maven-plugin/build-image.html)
+* [Docker Compose Support](https://docs.spring.io/spring-boot/3.4.5/reference/features/dev-services.html#features.dev-services.docker-compose)
+* [Spring Web](https://docs.spring.io/spring-boot/3.4.5/reference/web/servlet.html)
+
+### Guides
+The following guides illustrate how to use some features concretely:
+
+* [Building a RESTful Web Service](https://spring.io/guides/gs/rest-service/)
+* [Serving Web Content with Spring MVC](https://spring.io/guides/gs/serving-web-content/)
+* [Building REST services with Spring](https://spring.io/guides/tutorials/rest/)
+
+### Docker Compose support
+This project contains a Docker Compose file named `compose.yaml`.
+In this file, the following services have been defined:
+
+* postgres: [`postgres:latest`](https://hub.docker.com/_/postgres)
+
+Please review the tags of the used images and set them to the same as you're running in production.
+
+### Maven Parent overrides
+
+Due to Maven's design, elements are inherited from the parent POM to the project POM.
+While most of the inheritance is fine, it also inherits unwanted elements like `<license>` and `<developers>` from the parent.
+To prevent this, the project POM contains empty overrides for these elements.
+If you manually switch to a different parent and actually want the inheritance, you need to remove those overrides.
+

doma-spring-boot-samples/doma-spring-boot-sample-docker-compose/README.md

@@ -1,58 +1,69 @@
 # Doma Spring Boot Sample with Docker Compose
 
-This sample demonstrates how to use Doma with Spring Boot using Docker Compose.
+This sample demonstrates how to use Doma with Spring Boot's Docker Compose support.
 
 ## Requirements
 
 - Docker
 - Docker Compose
 
+## How it works
+
+This sample uses Spring Boot's built-in Docker Compose support, which automatically:
+
+1. Detects the `compose.yaml` file in the project root
+2. Starts the PostgreSQL container defined in the compose file
+3. Configures the application to connect to the database
+
+The `spring-boot-docker-compose` dependency enables this functionality, allowing the application to seamlessly integrate with Docker Compose services.
+
 ## Running the sample
 
 From the sample directory, run:
 
 ```bash
-docker compose up
+./mvnw spring-boot:run
 ```
 
-This will:
-1. Start a PostgreSQL database container
-2. Build the Spring Boot application
-3. Start the application container linked to the database
+Spring Boot will automatically:
+- Start the PostgreSQL container defined in compose.yaml
+- Configure the application to connect to the database
+- Run the application
 
 ## Using the application
 
-Once both containers are running, you can access the application at http://localhost:8080
+Once the application is running, you can access it at http://localhost:8080
 
 ### API Endpoints
 
 - `GET /` - List all messages
 - `GET /?text=hello` - Add a new message with the text "hello"
 
-## Running the application locally
+## Configuration
 
-If you want to run the application locally while using the Docker PostgreSQL database:
+The PostgreSQL configuration is defined in the `compose.yaml` file:
 
-1. Start only the database container:
-   ```bash
-   docker compose up postgres
-   ```
+```yaml
+services:
+  postgres:
+    image: 'postgres:latest'
+    environment:
+      - 'POSTGRES_DB=${POSTGRES_DB}'
+      - 'POSTGRES_PASSWORD=${POSTGRES_PASSWORD}'
+      - 'POSTGRES_USER=${POSTGRES_USER}'
+    ports:
+      - '5432'
+```
+
+Before running the application, you should set the following environment variables:
+- `POSTGRES_DB`: The name of the PostgreSQL database (e.g., "domadb")
+- `POSTGRES_USER`: The PostgreSQL username (e.g., "doma")
+- `POSTGRES_PASSWORD`: The PostgreSQL password
 
-2. Run the application:
-   ```bash
-   ./mvnw spring-boot:run
-   ```
+Spring Boot automatically configures the application to connect to this database.
 
 ## Notes
 
-- The PostgreSQL data is persisted in a Docker volume
-- The application connects to PostgreSQL using environment variables with default values
-- You can customize the database configuration by setting the following environment variables:
-  - `POSTGRES_DB`: Database name (default: domadb)
-  - `POSTGRES_USER`: Database username (default: doma)
-  - `POSTGRES_PASSWORD`: Database password (default: changeme)
+- No manual configuration of database connection properties is needed
 - The schema.sql file is automatically executed when the application starts
-
-## Security Note
-
-For production use, always set secure passwords through environment variables rather than using the defaults.
+- Spring Boot manages the lifecycle of the Docker containers

doma-spring-boot-samples/doma-spring-boot-sample-docker-compose/compose.yaml

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+services:
+  postgres:
+    image: 'postgres:latest'
+    environment:
+      - 'POSTGRES_DB=${POSTGRES_DB}'
+      - 'POSTGRES_PASSWORD=${POSTGRES_PASSWORD}'
+      - 'POSTGRES_USER=${POSTGRES_USER}'
+    ports:
+      - '5432'