## Compose sample application ### Java Spark application with MySQL database Project structure: ``` . ├── backend │   ├── Dockerfile │   └── ... ├── db │   └── password.txt ├── docker-compose.yaml └── README.md ``` [_docker-compose.yaml_](docker-compose.yaml) ``` services: backend: build: backend ports: - 8080:8080 db: image: mysql:8.0.19 ... ``` The compose file defines an application with two services `backend` and `db`. When deploying the application, docker-compose maps port 8080 of the backend service container to port 80 of the host as specified in the file. Make sure port 8080 on the host is not already being in use. ## Deploy with docker-compose ``` $ docker-compose up -d Creating network "sparkjava-mysql_default" with the default driver Building backend ... Successfully tagged sparkjava-mysql_backend:latest WARNING: Image for service backend was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`. Creating sparkjava-mysql_db_1 ... done Creating sparkjava-mysql_backend_1 ... done ``` ## Expected result Listing containers must show two containers running and the port mapping as below: ``` $ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES ee1e4f05d9f6 sparkjava-mysql_backend "/bin/sh -c 'java -j…" 44 seconds ago Up 43 seconds 0.0.0.0:8080->8080/tcp sparkjava-mysql_backend_1 716025ddf65b mysql:8.0.19 "docker-entrypoint.s…" 44 seconds ago Up 43 seconds 3306/tcp, 33060/tcp sparkjava-mysql_db_1 ``` After the application starts, run: ``` $ curl localhost:8080 ["Blog post #0","Blog post #1","Blog post #2","Blog post #3","Blog post #4"] ``` Stop and remove the containers ``` $ docker-compose down Stopping sparkjava-mysql_backend_1 ... done Stopping sparkjava-mysql_db_1 ... done Removing sparkjava-mysql_backend_1 ... done Removing sparkjava-mysql_db_1 ... done Removing network sparkjava-mysql_default ```