Talk is cheap

Files:

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> tree
.
├── app.py
├── docker-compose.yml
└── web.Dockerfile
  • docker-compose.yml
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version: "3"

services:

  redis:
    image: redis
    restart: always

  web:
    build:
      context: .
      dockerfile: web.Dockerfile
    depends_on: 
      - redis
    environment:
      REDIS_HOST: redis
    restart: always

  lb:
    image: dockercloud/haproxy
    links:
      - web
    ports:
      - 80:80
    depends_on: 
      - web
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    restart: always
  • app.py
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from flask import Flask
from redis import Redis
import os
import socket

app = Flask(__name__)
redis = Redis(host=os.environ.get('REDIS_HOST', '127.0.0.1'), port=6379)


@app.route('/')
def hello():
    redis.incr('hits')
    return 'Hello Container World! I have been seen %s times and my hostname is %s.\n' % (redis.get('hits'),socket.gethostname())


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=8000, debug=True)

  • web.Dockerfile
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FROM python:2.7
LABEL maintaner="simon.xie@codewalker.me"
COPY . /app
WORKDIR /app
RUN python -m pip install --upgrade pip && pip install flask redis
EXPOSE 8000
CMD [ "python", "app.py" ]

How to run

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docker-compose up -d

then you should see something like this:

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> docker-compose up
Starting scale_redis_1 ... done
Starting scale_web_1   ... done
Starting scale_lb_1    ... done
...
...
...
lb_1     |   maxconn 4096
lb_1     |   default_backend default_service
lb_1     | backend default_service
lb_1     |   server scale_web_1 scale_web_1:80 check inter 2000 rise 2 fall 3
lb_1     | INFO:haproxy:Launching HAProxy
lb_1     | INFO:haproxy:HAProxy has been launched(PID: 9)
lb_1     | INFO:haproxy:===========END===========

How to see

Open 127.0.0.1 in your browser whatever you like.

EOF
Enjoy
I, simon love this world ❤️