docker-compose.yml

docker:
    image: jpetazzo/dind
    privileged: true
    environment:
    - PORT=4444
transcoder:
  build: transcoder
  restart: always
  command: /usr/local/bin/gunicorn -w 2 -b :8000 app:app
  links:
    - docker
nginx:
  restart: always
  build: ./nginx/
  ports:
    - "8080:80"
  links:
    - transcoder

nginx Dockerfile

FROM tutum/nginx
RUN rm /etc/nginx/sites-enabled/default
ADD sites-enabled/ /etc/nginx/sites-enabled

nginx sites-enabled default

server {
    listen 80;
    server_name transcodertest.productgang.com;
    charset utf-8;

    location / {
        proxy_pass http://transcoder:8000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

transcoder app.py

from docker import Client
from flask import Flask, Response, request

app = Flask(__name__)
docker_client = Client(base_url='http://docker:4444')

@app.route('/', methods=['GET', ])
def transcode():
    url = request.args.get('url', '')
    
    container = docker_client.create_container(
        image='cellofellow/ffmpeg',
        command=['ffmpeg', '-hide_banner', '-loglevel', 'quiet', '-i', url, '-codec:a', 'libmp3lame', '-b:a', '160k', '-f', 'mp3', '-'],
    )
    docker_client.start(container)


    output = docker_client.attach(
        container=container,
        stdout=True,
        stream=True,
        logs=True,
    )
    
    return Response(output, mimetype='audio/mpeg')

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

transcoder Dockerfile

FROM python:3.4.3-onbuild

transcoder requirements.txt

flask==0.10.1
gunicorn==19.3.0
docker-py==1.2.2