## Compose sample application ### React application with a NodeJS backend and a MySQL database Project structure: ``` . ├── backend │   ├── Dockerfile │   ... ├── db │   └── password.txt ├── docker-compose.yaml ├── frontend │   ├── ... │   └── Dockerfile └── README.md ``` [_docker-compose.yaml_](docker-compose.yaml) ``` services: backend: build: backend ports: - 80:80 - 9229:9229 - 9230:9230 ... db: image: mysql:8.0.19 ... frontend: build: frontend ports: - 3000:3000 ... ``` The compose file defines an application with three services `frontend`, `backend` and `db`. When deploying the application, docker-compose maps port 3000 of the frontend service container to port 3000 of the host as specified in the file. Make sure port 3000 on the host is not already being in use. ## Deploy with docker-compose ``` $ docker-compose up -d Creating network "react-express-mysql_default" with the default driver Building backend Step 1/16 : FROM node:10 ---> aa6432763c11 ... Successfully tagged react-express-mysql_frontend:latest WARNING: Image for service frontend was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`. Creating react-express-mysql_db_1 ... done Creating react-express-mysql_backend_1 ... done Creating react-express-mysql_frontend_1 ... done ``` ## Expected result Listing containers must show containers running and the port mapping as below: ``` $ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES f3e1183e709e react-express-mysql_frontend "docker-entrypoint.s…" 8 minutes ago Up 8 minutes 0.0.0.0:3000->3000/tcp react-express-mysql_frontend_1 9422da53da76 react-express-mysql_backend "docker-entrypoint.s…" 8 minutes ago Up 8 minutes (healthy) 0.0.0.0:80->80/tcp, 0.0.0.0:9229-9230->9229-9230/tcp react-express-mysql_backend_1 a434bce6d2be mysql:8.0.19 "docker-entrypoint.s…" 8 minutes ago Up 8 minutes 3306/tcp, 33060/tcp react-express-mysql_db_1 ``` After the application starts, navigate to `http://localhost:3000` in your web browser. ![page](output.jpg) The backend service container has the port 80 mapped to 80 on the host. ``` $ curl localhost:80 {"message":"Hello Docker World!"} ``` Stop and remove the containers ``` $ docker-compose down Stopping react-express-mysql_frontend_1 ... done Stopping react-express-mysql_backend_1 ... done Stopping react-express-mysql_db_1 ... done Removing react-express-mysql_frontend_1 ... done Removing react-express-mysql_backend_1 ... done Removing react-express-mysql_db_1 ... done Removing network react-express-mysql_default ```