## Compose sample application ### Python/Flask application with Nginx proxy and a Mongo database Project structure: ``` . ├── docker-compose.yaml ├── flask │   ├── Dockerfile │   ├── requirements.txt │   └── server.py └── nginx    └── nginx.conf ``` [_docker-compose.yaml_](docker-compose.yaml) ``` services: web: build: app ports: - 80:80 backend: build: flask ... mongo: image: mongo ``` The compose file defines an application with three services `web`, `backend` and `db`. When deploying the application, docker-compose maps port 80 of the web service container to port 80 of the host as specified in the file. Make sure port 80 on the host is not being used by another container, otherwise the port should be changed. ## Deploy with docker-compose ``` $ docker-compose up -d Creating network "nginx-flask-mongo_default" with the default driver Pulling mongo (mongo:)... latest: Pulling from library/mongo 423ae2b273f4: Pull complete ... ... Status: Downloaded newer image for nginx:latest Creating nginx-flask-mongo_mongo_1 ... done Creating nginx-flask-mongo_backend_1 ... done Creating nginx-flask-mongo_web_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 a0f4ebe686ff nginx "/bin/bash -c 'envsu…" About a minute ago Up About a minute 0.0.0.0:80->80/tcp nginx-flask-mongo_web_1 dba87a080821 nginx-flask-mongo_backend "./server.py" About a minute ago Up About a minute nginx-flask-mongo_backend_1 d7eea5481c77 mongo "docker-entrypoint.s…" About a minute ago Up About a minute 27017/tcp nginx-flask-mongo_mongo_1 ``` After the application starts, navigate to `http://localhost:80` in your web browser or run: ``` $ curl localhost:80 Hello fom the MongoDB client! ``` Stop and remove the containers ``` $ docker-compose down ```