Scaling Nginx servers via Docker' (a Flask app)

README.md

How to use

Run: docker-compose up --scale flask=12

app.py

import socket
from flask import Flask

app = Flask(__name__)

@app.route('/')
def hello():
    return "Hello, My container is named: " + socket.gethostname()

docker-compose.yml

version: '3'
services:
  flask:
    build: .
    volumes:
      - ./py:/src
    environment:
      - FLASK_APP=/src/app.py
  nginx:
    image: nginx:latest
    ports:
      - "2000:80"
    volumes:
      - ./nginx:/etc/nginx/conf.d
    depends_on:
      - flask

Dockerfile

FROM python:3
RUN pip3 install flask
CMD flask run --host=0.0.0.0

nginx.conf

upstream serv {
  server docker-scaling_flask_1:5000;
  server docker-scaling_flask_2:5000;
  server docker-scaling_flask_3:5000;
  server docker-scaling_flask_4:5000;
  server docker-scaling_flask_5:5000;
  server docker-scaling_flask_6:5000;
  server docker-scaling_flask_7:5000;
  server docker-scaling_flask_8:5000;
  server docker-scaling_flask_9:5000;
  server docker-scaling_flask_10:5000;
  server docker-scaling_flask_11:5000;
  server docker-scaling_flask_12:5000;
}

server {
  listen: 80;
  location / {
    proxy_pass http://serv
  }
}

minimal and to the point! THANK YOU for sharing!

made some little (and likely not so great) updates to make it work after pulling.
https://gist.github.com/pangyuteng/8398773c00204c041dec9dad837aebf4