Allowing Remote Connection to MariaDB from Another VM

I have two VM, one is a database mariaDB server(10.0.0.1). How can I allow one VM(10.0.0.2) to connect to this DB?

To allow a VM (10.0.0.2) to connect to a MariaDB server running on another VM (10.0.0.1), you need to follow these steps:

Step 1: Configure MariaDB to Allow Remote Connections

1. Edit the MariaDB Configuration File:

   • Open the MariaDB configuration file, usually located at /etc/mysql/my.cnf or /etc/my.cnf.
   • Look for the line that starts with bind-address. By default, it may be set to 127.0.0.1, which restricts connections to localhost.
   • Change it to 0.0.0.0 to allow connections from any IP address, or specify the IP address of the VM (10.0.0.1) if you want to restrict it further.

   [mysqld]
   bind-address = 0.0.0.0
   

2. Restart the MariaDB Service:

   • After making changes to the configuration file, restart the MariaDB service to apply the changes.

   sudo systemctl restart mariadb
   

Step 2: Create a User for Remote Access

1. Log in to the MariaDB Server:

   • Use the following command to log in to the MariaDB server:

   mysql -u root -p
   

2. Create a User for Remote Access:

   • You can create a user that allows connections from the specific IP address (10.0.0.2) or from any IP address (%).

   CREATE USER 'username'@'10.0.0.2' IDENTIFIED BY 'password';
   

   • If you want to allow access from any IP address, use:

   CREATE USER 'username'@'%' IDENTIFIED BY 'password';
   

3. Grant Privileges:

   • Grant the necessary privileges to the user for the database you want to access. For example, to grant all privileges on a specific database:

   GRANT ALL PRIVILEGES ON database_name.* TO 'username'@'10.0.0.2';
   

   • If you used %, replace 10.0.0.2 with % in the command.

4. Flush Privileges:

   • After creating the user and granting privileges, run the following command to ensure that the changes take effect:

   FLUSH PRIVILEGES;
   

5. Exit MariaDB:

   EXIT;
   

Step 3: Configure Firewall (if applicable)

If you have a firewall running on the MariaDB server (10.0.0.1), you need to allow incoming connections on the default MariaDB port (3306).

1. Using UFW (Uncomplicated Firewall):

   sudo ufw allow from 10.0.0.2 to any port 3306
   

2. Using iptables:

   sudo iptables -A INPUT -p tcp -s 10.0.0.2 --dport 3306 -j ACCEPT
   

3. Using firewalld:

   sudo firewall-cmd --zone=public --add-rich-rule='rule family="ipv4" source address="10.0.0.2" port protocol="tcp" port="3306" accept'
   sudo firewall-cmd --runtime-to-permanent
   

Step 4: Connect from the Client VM

Now, you can connect to the MariaDB server from the client VM (10.0.0.2) using the following command:

mysql -u username -p -h 10.0.0.1

You will be prompted to enter the password for the user you created.

Troubleshooting

• If you encounter issues connecting, check the following:
  • Ensure that the MariaDB service is running.
  • Verify that the firewall rules are correctly set.
  • Check the MariaDB logs for any error messages.
  • Ensure that the user has the correct privileges.

By following these steps, you should be able to successfully connect from one VM to the MariaDB server running on