How to Install MODX Revolution on a CentOS 7 LAMP VPS

MODX Revolution is a fast, flexible, scalable, free and open source, enterprise-grade Content Management System (CMS) written in PHP. It is particularly well-suited to building high-end sites since it features advanced multi-lingual capabilites, and is built from the ground up using secure design principles.

In this tutorial we are going to install MODX Revolution 2.6.0 CMS on a CentOS 7 LAMP VPS.

Prerequisites

• A clean Vultr CentOS 7 server instance with SSH access

Step 1: Add a Sudo User

We will start by adding a new sudo user.

First, log into your server as root.

ssh root@YOUR_VULTR_IP_ADDRESS

Add a new user called user1 (or your preferred username).

useradd user1

Next, set the password for the user1 user.

passwd user1

When prompted, enter a secure and memorable password.

Now check the /etc/sudoers file to make sure that the sudoers group is enabled.

visudo

Look for a section like this.

%wheel        ALL=(ALL)       ALL

This line tells us that users who are members of the wheel group can use the sudo command to gain root privileges. It should be uncommented by default, so you can simply exit the file.

Next we need to add user1 to the wheel group.

usermod -aG wheel user1

We can verify the user1 group membership and check that the usermod command worked with the groups command.

groups user1

Now use the su command to switch to the new sudo user user1 account.

su - user1

The command prompt will update to indicate that you are now logged into the user1 account. You can verify this with the whoami command.

whoami

Now restart the sshd service so that you can login via ssh with the new non-root sudo user account you have just created.

sudo systemctl restart sshd

Exit the user1 account.

exit

And exit the root account (which will disconnect your ssh session).

exit

You can now ssh into the server instance from your local host using the new non-root sudo user user1 account.

ssh user1@YOUR_VULTR_IP_ADDRESS

If you want to execute sudo without having to type a password every time, then open the /etc/sudoers file again, using visudo.

sudo visudo

Edit the section for the wheel group so that it looks like this.

%wheel        ALL=(ALL)       NOPASSWD: ALL

Please note: Disabling the password requirement for the sudo user is not a recommended practice, but it is included here as it can make server configuration much more convenient and less frustrating, especially during longer systems administration sessions. If you are concerned about the security implications, you can always revert the configuration change to the original after you finish your administration tasks.

Whenever you want to log into the root user account from within the sudo user account, you can use one of the following commands.

sudo -i
sudo su -

You can exit the root account and return back to your sudo user account any time.

exit

Step 2: Update CentOS 7

Before installing any packages on the CentOS server instance, we will first update the system.

Make sure you are logged in to the server using a non-root sudo user and run the following command.

sudo yum -y update

Step 3: Install Apache

Install the Apache web server.

sudo yum -y install httpd

Then use the systemctl command to start and enable Apache to execute automatically at boot time.

sudo systemctl enable httpd
sudo systemctl start httpd

Check your Apache configuration file to ensure that the DocumentRoot directive points to the correct directory.

sudo vi /etc/httpd/conf/httpd.conf

The DocumentRoot configuration option should look like this.

DocumentRoot "/var/www/html"

Now, let's make sure that the mod_rewrite Apache module is loaded. We can do this by searching the Apache base modules configuration file for the term "mod_rewrite".

Open the file.

sudo vi /etc/httpd/conf.modules.d/00-base.conf

Search for the term "mod_rewrite".

If the mod_rewrite Apache module is loaded, you should find a configuration line looking like this.

LoadModule rewrite_module modules/mod_rewrite.so

If the above line starts with a semi-colon, you will need to remove the semi-colon to uncomment the line and load the module. This, of course, applies to any other required Apache modules too.

We will restart Apache at the end of this tutorial, but restarting Apache regularly during installation and configuration is certainly a good habit, so let's do it now.

sudo systemctl restart httpd

Step 4: Open Web Firewall Ports

We now need to open the default HTTP and HTTPS ports as they will be blocked by firewalld by default.

Open the firewall ports.

sudo firewall-cmd --permanent --add-port=80/tcp
sudo firewall-cmd --permanent --add-port=443/tcp

Reload the firewall to apply the changes.

sudo firewall-cmd --reload

You should see the word success displayed in your terminal after each successful firewall configuration command.

We can quickly verify that the Apache HTTP port is open by visiting the IP address or domain of the server instance in a browser.

http://YOUR_VULTR_IP_ADDRESS/

If everything is set up correctly, you will see the default Apache web page in your browser.

Step 5: Disable SELinux (if enabled)

SELinux stands for "Security Enhanced Linux". It is a security enhancement to Linux which allows users and administrators more control over access control. It is disabled by default on Vultr CentOS 7 instances, but we will cover the steps to disable it, just in case you are not starting from a clean install and it was previously enabled.

To avoid file permission problems with MODX Revolution CMS, we need to ensure that SELinux is disabled.

First, let's check whether SELinux is enabled or disabled with the sestatus command.

sudo sestatus

If you see something like: SELinux status: disabled then it is definitely disabled and you can skip straight to Step 6. If you see any other message, then you will need to complete this section.

Open the SELinux configuration file with your favourite terminal editor.

sudo vi /etc/selinux/config

Change SELINUX=enforcing to SELINUX=disabled and then save the file.

To apply the configuration change, SELinux requires a server reboot, so you can either restart the server using the Vultr control panel or you can simply use the shutdown command.

sudo shutdown -r now

When the server reboots, your SSH session will get disconnected and you may see a message complaining about a 'broken pipe' or informing you 'Connection closed by remote host'. This is nothing to worry about, simply wait for 20 seconds or so and then SSH back in again with your own username and domain.

ssh user1@YOUR_DOMAIN

Or with your own username and IP address.

ssh user1@YOUR_VULTR_IP_ADDRESS

Once you have logged back in, you should check the status of SELinux again with the sestatus command to make sure it is properly disabled.

sudo sestatus

You should see a message saying SELinux status: disabled. If you see a message saying SELinux status: enabled (or something similar) you will need to repeat the above steps and ensure that you properly restart your server.

Step 6: Install PHP 5.4

We can now install PHP 5.4 along with the necessary PHP modules required by MODX Revolution CMS.

sudo yum -y install php php-mbstring php-gd php-common php-pdo php-pecl-imagick php-mysqlnd

Step 7: Install MariaDB (MySQL)

CentOS 7 defaults to using MariaDB, which is an enhanced, fully open source, community developed, drop-in replacement for MySQL.

Install MariaDB.

sudo yum -y install mariadb-server

Start and enable MariaDB to execute automatically at boot time.

sudo systemctl enable mariadb
sudo systemctl start mariadb    

Secure your MariaDB server installation.

sudo mysql_secure_installation

The root password will be blank, so simply hit "enter" when prompted for the root password.

When prompted to create a MariaDB/MySQL root user, select "Y" (for yes) and then enter a secure root password. Simply answer "Y" to all of the other yes/no questions as the default suggestions are the most secure options.

Step 8: Create a Database for MODX Revolution

Log into the MariaDB shell as the MariaDB root user by running the following command.

sudo mysql -u root -p

To access the MariaDB command prompt, simply enter the MariaDB root password when prompted.

Run the following queries to create a MariaDB database and database user for MODX Revolution.

CREATE DATABASE modx_data CHARACTER SET utf8 COLLATE utf8_general_ci;
CREATE USER 'modx_user'@'localhost' IDENTIFIED BY 'UltraSecurePassword';
GRANT ALL PRIVILEGES ON modx_data.* TO 'modx_user'@'localhost';
FLUSH PRIVILEGES;
EXIT;

You can replace the database name modx_data and username modx_user with something more to your liking, if you prefer. (Please note that the default maximum length for usernames in MariaDB on CentOS 7 is 16 characters). Also, make sure that you replace "UltraSecurePassword" with an actually secure password.

Step 9: Install MODX Revolution Files

Change your current working directory to the default web directory.

cd /var/www/html/

If you get an error message saying something like 'No such file or directory' then try the following command.

cd /var/www/ ; sudo mkdir html ; cd html

Your current working directory should now be /var/www/html/. You can check this with the pwd (print working directory) command.

pwd

Now use wget to download the MODX Revolution installation zip package.

sudo wget https://modx.com/download/direct?id=modx-2.6.0-pl.zip

Please note: You should definitely check for the most recent version by visiting the MODX Revolution download page.

List the current directory to check that you have successfully downloaded the file.

ls -la

Quickly install unzip so you can unzip the file.

sudo yum -y install unzip

Let's give the package a simpler name.

sudo mv direct\?id\=modx-2.6.0-pl.zip modx.zip

Now uncompress the zip package.

sudo unzip modx.zip

Move all of the installation files to the web root directory.

sudo mv modx-2.6.0-pl/* /var/www/html

Change ownership of the web files to avoid any permissions problems.

sudo chown -R apache:apache * 

Restart Apache again.

sudo systemctl restart httpd

Now we're ready to move on to the final step.

Step 10: Complete MODX Revolution Installation

It's time to visit the IP address of your CentOS 7 server instance in your browser. Or, if you've already configured your Vultr DNS settings (and given it enough time to propagate) you can simply visit your domain instead.

To access the MODX Revolution installation page, enter your Vultr instance IP address, followed by /setup into your browser address bar.

http://YOUR_VULTR_IP_ADDRESS/setup

Most of the installation options are self explanatory, but here are a few pointers to help you along.

Select your language.

Click the Next button to continue the installation.

Select New Installation and leave the folder permissions at their default values. Click Next when you are ready to move on to the next step

Set the following database options.

Database type:          mysql
Database host:          localhost
Database login name:    modx_user (or your previously selected name)
Database password:      UltraSecurePassword (or your previously chosen password)
Database name:          modx_data (or your previously selected name)
Table prefix:           modx_

Once you have entered the above database options, click on the link below to Test database server connection and view collations. You will see a message that says Connecting to database server: Success!. If you get any errors, go back and ensure that all database options are correct.

You can leave the character set and collation options at their default values. They should look like this.

Connection character set:   utf8
Collation:                  utf8_general_ci

When you are satisfied with your selected installation options, you can click on the link below to Create or test selection of your database.

You will be prompted to enter your admin details, which will be used to login to the CMS. Fill them in as shown below and click Next.

Administrator name:         <your_prefered_admin_name>
Administrator email:        <your_admin_email>
Administrator password:     <a_secure_password
Confirm password:           <the_same_secure_password>

You will see an Installation Summary. As long as everything looks okay, you can simply click Install to Install MODX Revolution to your server instance.

You will see a confirmation page that says Core installation was successful. Simply click Next to continue.

You can now login to your MODX Revolution admin panel using the login details you entered earlier during installation.

Please note: During installation and login, you may see some warning messages about directories and files. Simply follow the instructions shown on the warning pages and the warning messages will disappear.

If you haven't already set up your Vultr DNS, that should probably be your next step.

Now you can start adding your content and start configuring the look of your site. Be sure to check out the excellent MODX Revolution docs for more guidance on how to build and configure your site.