How to Compose a Flask API with Docker

You can compose a Flask API as follows: The project structure will look like:

.
├── docker-compose.yaml
├── app
    ├── Dockerfile
    ├── requirements.txt
    └── app.py

The docker-compose.yml will be:

version: '3' 
services: 
  web: 
    build: app 
    ports: 
      - '5000:5000'

The Dockerfile will be:

FROM python:3.7-alpine 
WORKDIR /app 
COPY requirements.txt /app
RUN pip3 install -r requirements.txt 
COPY . /app 
ENTRYPOINT ["python3"] 
CMD ["app.py"]

The requirements.txt will be:

flask

and the app.py will be:

from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello():
	return "Hello World!"

if __name__ == '__main__':
	app.run(host='0.0.0.0')

Of course the files above is just an example of a basic “Hello World!” Flask API