Dockerized Nginx upstream error serving separate Docker container with Flask/uWSGI app

Question

I am experiencing the following error with my multi-container Docker setup after running docker-compose build && docker-compose up and attempting to hit my index page:

 [error] 8#8: *1 connect() failed (111: Connection refused) while connecting to upstream, client: 192.168.99.1, server: localhostz, request: "GET / HTTP/1.1", upstream: "uwsgi://172.17.0.39:8000", host: "192.168.99.100"

Here is my docker-compose.yml:

web:
  restart: always
  build: ./web-app
  expose:
    - "8000"
  command: /usr/local/bin/uwsgi --ini sample-uwsgi.ini

nginx:
  restart: always
  build: ./nginx/
  ports:
    - "80:80"
  links:
    - web:web

nginx/Dockerfile

FROM nginx
RUN rm /etc/nginx/conf.d/default.conf
ADD sample-nginx.conf /etc/nginx/conf.d/

nginx/sample-nginx.conf

upstream flask {
    server web:8000;
}

server {

    listen 80;
    server_name localhostz;
    charset utf-8;
    client_max_body_size 75M;

    location / {
        uwsgi_pass flask;
        include uwsgi_params;
    }
}

web-app/Dockerfile

FROM ansible/ubuntu14.04-ansible:stable

WORKDIR /root
ADD application.py application.py
ADD requirements.txt requirements.txt
ADD sample-uwsgi.ini sample-uwsgi.ini

ADD ansible /srv/ansible
WORKDIR /srv/ansible

RUN ansible-playbook container-bootstrap.yml -c local

web-app/sample-uswgi.ini

[uwsgi]

module = application
callable = app

master = true
processes = 5

socket = web:8000

chown-socket = www-data:www-data

vacuum = true
enable-threads=True
die-on-term = true

Please do not post suggestions regarding a single container setup. I am doing as an exercise in being able to scale Docker app containers served under a single nginx container.

Erik Erik · Accepted Answer · 2015-09-09T18:08:04

Secret sauce was changing the socket line in sample-uwsgi.ini to:

socket = 0.0.0.0:8000

Dockerized Nginx upstream error serving separate Docker container with Flask/uWSGI app

1 Answers