Establish Connection between MySQL and Apache in a Containerized Web Application

This blog is the continuation of the previous blog of build a Containerized Web Application on Azure (Click here to read the previous blog) . In this blog, we will establish a connection between mysql-container and apache-container.

Now watch those containers with this command:

watch 'sudo docker ps -a'

If mysql-container stops then restart it using following command:

sudo docker start mysql-container

Open the mysql-container shell using the following command and check the status of the mySQL service.

sudo docker exec -it mysql-container bash
service mysql status

If MySQL service is not running then start it using the following command:

service mysql start

We have installed the network tools in the apache-container. Now install the network tools in the mysql-container.

apt install inetutils-ping net-tools -y

Checking Connection

Check network cards in the mysql-container.

ifconfig

And note down the IPaddress of the mysql-container and exit from this container and move to host machine. In my case, It is 172.17.0.2.

Check apache-container is running or not. If apache-container is not running then start the apache container.

sudo docker start apache-container

Now open the apache-container shell and ping the mysql-container on the IPaddress and check everything is working fine or not.

sudo docker exec -it apache-container bash
ping 172.117.0.2

Now note down the IPaddress of the apache-container and exit from this container and move to host machine.

ifconfig

In my case, It is 172.17.0.3.

And then open the mysql-container shell and then ping the apache-container and check everything is working fine or not.

sudo docker exec -it mysql-container bash
ping 172.17.0.3
exit

Configuration Setting

Now come to the apache container and Now open the apache-container shell.

sudo docker exec -it apache-container bash

Now connect mysql database to the php. Open the index.php file with using following command:

vi /var/www/html/index.php

And add this code in this file.

<?php
    $server = "172.17.0.2";
    $username = "test";
    $pass = "test123!";
    $dbname = "mysql";

    $con = new MySQLi($server, $username, $pass, $dbname);

    if ($con->connect_error)
        echo "Error: ".$con->connect_error;
    else
        echo "connected";
?>

Start the apache server first with the following command:

service apache2 start

Exit from the apache container and go to mysql-container.And check the listening ports.

sudo docker exec -it mysql-container bash
netstat -nutlp

MySQL by default accepting only from local host. So we have to change it to listen from the apache-container as well.

So, you have to change it to accept it from remote as well and this setting is in conf and conf is in the /etc/mysql and you have to search for it.

grep -r "bind-address" /etc/mysql/

You will get this output.

/etc/mysql/mysql.conf.d/mysqld.cnf:bind-address = 127.0.0.1

Now open the file using the path as described in the above output.

vi /etc/mysql/mysql.conf.d/mysqld.cnf

Now change bind addresses to listen from all ports.

bind-addresses = 0.0.0.0

Now restart the MySQL server.

service mysql restart

Change MySQL Server user setting from local host to the remote network. It’s good to create sperate user for different work do not give full access to every user so in this case I am not opening my database to everyone but just this apache-container giving rights only on mysql database. You can see that I have created the test user in index.php file above.

mysql -uroot -p
CREATE USER 'test'@'172.17.0.3' IDENTIFIED BY 'test123!';
GRANT ALL PRIVILEGES ON mysql.* TO 'test'@'172.17.0.3' WITH GRANT OPTION;
\q;

Now all connection is good. Now go to browser and search for this address 172.17.0.3. And your connection is working.