In this tutorial, I am demonstrating how easy it is to create a stack (a development/production environment) of your own using docker-compose. I am going to create a LEMP stack (Linux - nginx - MariaDB - PHP 5.6). I’m not eager to write my own image yet because, well, there are already images available for nginx, MariaDB, and PHP 5.6. What I want is to link them together to create my own service.

1. Go to docker hub and search for nginx, mariadb, and php, and choose the images that I want to use to compose my stack
   • nginx:1.11.8-alpine
   • mariadb:5.5
   • php:5.6-fpm-alpine

   The reason I choose alpine image over other images is that alpine images are usually much smaller.

2. Create a project folder for the LEMP stack

    mkdir LEMP
    cd LEMP
   

3. Create a www folder to contain PHP source code, and make a phpinfo() test script

    mkdir www
    echo "<?php phpinfo(); ?>" > ./www/index.php
   

4. Create a folder for containing log files

    mkdir logs
   

5. Create a ./nginx/site.conf file containing the server’s configuration

    server {
        listen 80;
   
        root /www;
   
        index index.html index.htm index.php;
   
        location / {
            try_files $uri $uri/ /index.php?$args;
        }
   
        location ~ \.php$ {
            try_files $uri =404;
            include fastcgi_params;
            fastcgi_pass phpfpm:9000;
            fastcgi_index index.php;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        }
    }
   

   This is pretty much a standard configuration for an nginx-phpfpm site. Except this line:

    fastcgi_pass phpfpm:9000;
   

   We are going to link the nginx container with the phpfpm container, thus phpfpm will be available in the nginx container’s hosts

6. Create a docker-compose.yml file with the following content

    version: '2'
    services:
        mariadb:
            image: mariadb:5.5
            user: $UID
            environment:
            - MYSQL_ROOT_PASSWORD=password123
            - MYSQL_DATABASE=yii
            - MYSQL_USER=yii
            - MYSQL_PASSWORD=abcd1234
        phpfpm:
            image: php:5.6-fpm-alpine
            user: $UID
            volumes:
            - ./www:/www
            links:
            - mariadb
        nginx:
            image: nginx:1.11.8-alpine
            user: $UID
            volumes:
            - ./nginx:/etc/nginx/conf.d
            - ./logs:/var/nginx/logs
            - ./www:/www
            ports:
            - 80:80
            links:
            - phpfpm
            command: /bin/sh -c "nginx -g 'daemon off;'"
   

   Things here are pretty straightforward:

   • We have 3 services in our stack: mariadb, nginx, and phpfpm
   • What environment does is obvious
   • ./nginx will be mounted to nginx’s sites folder
   • ./logs will be mounted to nginx’s logs folder
   • ./www will be mounted on both nginx and phpfpm containers, so the php process will also have access to the same file paths as nginx
   • mariadb is linked to phpfpm, and phpfpm is linked to nginx. There’s no need for nginx to link with mariadb, since static files don’t make database connections

7. Check your folder’s structure

    $ tree ./
    ./
    ├── docker-compose.yml
    ├── logs
    ├── nginx
    │   └── site.conf
    └── www
        └── index.php
   

8. Run the stack

    export UID
    docker-compose up -d
   

9. Go to localhost and check if your phpinfo() script has been successfully executed

10. Testing database connection by replacing the content of ./www/index.php with the following

    <?php
    $servername = "mariadb";
    $username = "yii";
    $password = "abcd1234";
    
    // Create connection
    $conn = new mysqli($servername, $username, $password);
    
    // Check connection
    if ($conn->connect_error) {
        die("Connection failed: " . $conn->connect_error);
    }
    echo "Connected successfully";
    ?>
    

    There should be an error message that says something like this

    Fatal error: Class 'mysqli' not found in /www/index.php on line 7
    

    We’ll just have to install mysqli. Luckily, it isn’t too complicated. The instructions are already on the php docker hub repo

    docker exec lemp_phpfpm_1 docker-php-ext-install mysqli
    

    Restart the service

    docker-compose restart
    

11. Now, again, connect to localhost. It should say Connected successfully