How to correctly link php-fpm and Nginx Docker containers?

Question

I am trying to link 2 separate containers:

• nginx:latest
• php:fpm

The problem is that php scripts do not work. Perhaps the php-fpm config

Answer 1

As pointed out before, the problem was that the files were not visible by the fpm container. However to share data among containers the recommended pattern is using data-only containers (as explained in this article).

Long story short: create a container that just holds your data, share it with a volume, and link this volume in your apps with volumes_from.

Using compose (1.6.2 in my machine), the docker-compose.yml file would read:

version: "2"
services:
  nginx:
    build:
      context: .
      dockerfile: nginx/Dockerfile
    ports:
      - "80:80"
    links:
      - fpm
    volumes_from:
      - data
  fpm:
    image: php:fpm
    volumes_from:
      - data
  data:
    build:
      context: .
      dockerfile: data/Dockerfile
    volumes:
      - /var/www/html

Note that data publishes a volume that is linked to the nginx and fpm services. Then the Dockerfile for the data service, that contains your source code:

FROM busybox

# content
ADD path/to/source /var/www/html

And the Dockerfile for nginx, that just replaces the default config:

FROM nginx

# config
ADD config/default.conf /etc/nginx/conf.d

For the sake of completion, here's the config file required for the example to work:

server {
    listen 0.0.0.0:80;

    root /var/www/html;

    location / {
        index index.php index.html;
    }

    location ~ \.php$ {
        include fastcgi_params;
        fastcgi_pass fpm:9000;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME $document_root/$fastcgi_script_name;
    }
}

which just tells nginx to use the shared volume as document root, and sets the right config for nginx to be able to communicate with the fpm container (i.e.: the right HOST:PORT, which is fpm:9000 thanks to the hostnames defined by compose, and the SCRIPT_FILENAME).