I'm learning Docker and am still pretty new to it. I'm trying to get PHP 7 FPM, Nginx and MariaDB to work together (
I'm using [this](https://github.com/DanielDent/docker-php-7-fpm/blob/master/Dockerfile) version of PHP 7 FPM because it come with MySQLi already installed) but I receive the following error:

> 
> **Warning**: mysqli\_connect(): (HY000/2002): No such file or directory in **/usr/share/nginx/html/index.php** on line **4**  
> 
>  Error: Unable to connect to MySQL.
>  Debugging errno: 2002
>  Debugging error: No such file or directory
> 
> 
> 

My index.php looks like this:

```
<?php
  header('Content-Type: application/json');

  $link = mysqli_connect("localhost", "admin", "admin", "admin");

  if (!$link) {
      echo "Error: Unable to connect to MySQL." . PHP_EOL;
      echo "Debugging errno: " . mysqli_connect_errno() . PHP_EOL;
      echo "Debugging error: " . mysqli_connect_error() . PHP_EOL;
      exit;
  }

  echo "Success: A proper connection to MySQL was made! The my_db database is great." . PHP_EOL;
  echo "Host information: " . mysqli_get_host_info($link) . PHP_EOL;

  mysqli_close($link);

```

and my Dockerfile looks like this:

```
version: '2'
services:
  nginx:
    image: nginx:latest
    ports:
      - "80:80"
    volumes:
      - ./nginx/site.conf:/etc/nginx/conf.d/default.conf
      - ./logs/nginx-error.log:/var/log/nginx/error.log
      - ./logs/nginx-access.log:/var/log/nginx/access.log
      - ./public:/usr/share/nginx/html
    links:
      - php:php

  php:
    image: danieldent/php-7-fpm
    volumes:
      - ./public:/usr/share/nginx/html
      - ./logs/log.conf:/usr/local/etc/php-fpm.d/zz-log.conf
      - ./PHP/php.ini:/etc/php/7.0/fpm/php.ini
      - ./PHP/php.ini:/usr/local/etc/php/conf.d/php.ini
    links:
      - mariadb:mysqlip

  mariadb:
    image: mariadb:latest
    environment:
      MYSQL_ROOT_PASSWORD: pw
    stdin_open: true
    tty: true
    ports:
      - 3306:3306/tcp
    labels:
      io.rancher.container.pull_image: always
    volumes:
      - ./database:/var/lib/mysql

  phpmyadmin:
    image: phpmyadmin/phpmyadmin
    links:
      - mariadb:db

```

The php\_mysqli.dll extension is also enabeled in my php.ini file.

Again I'm still pretty new to docker but really want to get this working, thanks for any suggestions.