Docker Compose and Mysql not running on localhost

Question

I'm using a Docker Compose Lamp Stack environment from this github repo . It works well, however I can't connect to mysql via localhost. While testing database connection I had to set my server name to "database" for it to work.

I'm sure this is caused by something within the docker-compose.yml set up, but despite trying to change container_name: 'database' to container_name: 'localhost', I couldn't get it to change.

While this isn't a massive problem, the application I'm developing doesn't allow me to easily change its server name settings, hence why I can't use 'database'.

What is causing this? Do I need to completely reset docker compose for changes to docker-compose.yml to take effect? What are the commands to do so?

Edit: My current docker-compose.yml is:

version: "3"

services:
  webserver:
    build:
      context: ./bin/${PHPVERSION}
    container_name: ${PHPVERSION}
    restart: 'always'
    ports:
      - "${HOST_MACHINE_UNSECURE_HOST_PORT}:80"
      - "${HOST_MACHINE_SECURE_HOST_PORT}:443"
    network_mode: host
    volumes:
      - ${DOCUMENT_ROOT-./www}:/var/www/html
      - ${PHP_INI-./config/php/php.ini}:/usr/local/etc/php/php.ini
      - ${VHOSTS_DIR-./config/vhosts}:/etc/apache2/sites-enabled
      - ${LOG_DIR-./logs/apache2}:/var/log/apache2
  database:
    build:
      context: "./bin/${DATABASE}"
    container_name: 'database'
    restart: 'always'
    ports:
      - "127.0.0.1:${HOST_MACHINE_MYSQL_PORT}:3306"
    volumes:
      - ${MYSQL_DATA_DIR-./data/mysql}:/var/lib/mysql
      - ${MYSQL_LOG_DIR-./logs/mysql}:/var/log/mysql
    environment:
      MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
      MYSQL_DATABASE: ${MYSQL_DATABASE}
      MYSQL_USER: ${MYSQL_USER}
      MYSQL_PASSWORD: ${MYSQL_PASSWORD}
  phpmyadmin:
    image: phpmyadmin/phpmyadmin
    container_name: 'phpmyadmin'
    environment:
      PMA_HOST: database
      PMA_PORT: 3306
      PMA_USER: ${MYSQL_USER}
      PMA_PASSWORD: ${MYSQL_PASSWORD}
      MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
      MYSQL_USER: ${MYSQL_USER}
      MYSQL_PASSWORD: ${MYSQL_PASSWORD}
    ports:
      - '8080:80'
    volumes:
      - /sessions
      - ${PHP_INI-./config/php/php.ini}:/usr/local/etc/php/conf.d/php-phpmyadmin.ini
  redis:
    container_name: 'redis'
    image: redis:latest
    ports:
      - "127.0.0.1:${HOST_MACHINE_REDIS_PORT}:6379"

However if I try to connect via localhost like this:

<?php
$servername = "localhost";
$username = "user";
$password = "pass";

// Create connection
$conn = new mysqli($servername, $username, $password);

// Check connection
if ($conn->connect_error) {
  die("Connection failed: " . $conn->connect_error);
}
echo "Connected successfully";
?>

I get the following error:

Answer 1

It's the service name in docker-compose.yml which is database . https://github.com/sprintcube/docker-compose-lamp/blob/master/docker-compose.yml#L19

Changing container name won't affect the connection string.

If you will change the service name on that Line, make sure you change the --links section as well in the docker-compose.

https://github.com/sprintcube/docker-compose-lamp/blob/master/docker-compose.yml#L38

and PMA_HOST as well.

Ref: https://github.com/sprintcube/docker-compose-lamp/blob/master/docker-compose.yml#L40

Once all changes are done, Execute the below command.

docker-compose up --build --remove-orphans

In case, you face any error, please run this command

docker-compose down

and then run the first command again.

Updated Docker-compose.yml to be able to connect via localhost

version: "3"

services:
  webserver:
    build: 
      context: ./bin/${PHPVERSION}
    container_name: ${PHPVERSION}
    restart: 'always'
    ports:
      - "${HOST_MACHINE_UNSECURE_HOST_PORT}:80"
      - "${HOST_MACHINE_SECURE_HOST_PORT}:443"
    network_mode: host # Changed
    volumes: 
      - ${DOCUMENT_ROOT-./www}:/var/www/html
      - ${PHP_INI-./config/php/php.ini}:/usr/local/etc/php/php.ini
      - ${VHOSTS_DIR-./config/vhosts}:/etc/apache2/sites-enabled
      - ${LOG_DIR-./logs/apache2}:/var/log/apache2
  database:
    build:
      context: "./bin/${DATABASE}"
    container_name: 'database'
    restart: 'always'
    ports:
      - "127.0.0.1:${HOST_MACHINE_MYSQL_PORT}:3306"
    volumes: 
      - ${MYSQL_DATA_DIR-./data/mysql}:/var/lib/mysql
      - ${MYSQL_LOG_DIR-./logs/mysql}:/var/log/mysql
    environment:
      MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
      MYSQL_DATABASE: ${MYSQL_DATABASE}
      MYSQL_USER: ${MYSQL_USER}
      MYSQL_PASSWORD: ${MYSQL_PASSWORD}
  phpmyadmin:
    image: phpmyadmin/phpmyadmin
    container_name: 'phpmyadmin'
    links:
      - database
    environment:
      PMA_HOST: database
      PMA_PORT: 3306
      PMA_USER: ${MYSQL_USER}
      PMA_PASSWORD: ${MYSQL_PASSWORD}
      MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
      MYSQL_USER: ${MYSQL_USER}
      MYSQL_PASSWORD: ${MYSQL_PASSWORD}
    ports:
      - '8080:80'
    volumes: 
      - /sessions
      - ${PHP_INI-./config/php/php.ini}:/usr/local/etc/php/conf.d/php-phpmyadmin.ini
  redis:
    container_name: 'redis'
    image: redis:latest
    ports:
      - "127.0.0.1:${HOST_MACHINE_REDIS_PORT}:6379"