Introduction

WordPress is the most popular CMS (content management system) on the internet. It allows you to easily set up flexible blogs and websites on top of a MySQL backend with PHP processing. WordPress has seen incredible adoption and is a great choice for getting a website up and running quickly. After setup, almost all administration can be done through the web frontend.

In this guide, we'll focus on getting a WordPress instance set up on a LEMP stack (Linux, Nginx, MySQL, and PHP) on a Debian 9 server.

Prerequisites

In order to complete this tutorial, you will need access to a Debian 9 server.

You will need to perform the following tasks before you can start this guide:

• Create a sudo user on your server: We will be completing the steps in this guide using a non-root user with sudo privileges. You can create a user with sudo privileges by following our Debian 9 initial server setup guide.
• Install a LEMP stack: WordPress will need a web server, a database, and PHP in order to correctly function. Setting up a LEMP stack (Linux, Nginx, MySQL, and PHP) fulfills all of these requirements. Follow this guide to install and configure this software.
• Secure your site with SSL: WordPress serves dynamic content and handles user authentication and authorization. TLS/SSL is the technology that allows you to encrypt the traffic from your site so that your connection is secure. This tutorial will assume that you have a domain name for your blog. You can use Let's Encrypt to get a free SSL certificate for your domain. Follow our Let's Encrypt guide for Nginx to set this up.

When you are finished the setup steps, log into your server as your sudo user and continue below.

Step 1 — Creating a MySQL Database and User for WordPress

The first step that we will take is a preparatory one. WordPress uses MySQL to manage and store site and user information. We have MySQL installed already, but we need to make a database and a user for WordPress to use.

To get started, log into the MySQL root (administrative) account. If MySQL is configured to use the auth_socket authentication plugin (the default), you can log into the MySQL administrative account using sudo:

sudo mysql

If you changed the authentication method to use a password for the MySQL root account, use the following format instead:

mysql -u root -p

You will be prompted for the password you set for the MySQL root account.

First, we can create a separate database that WordPress can control. You can call this whatever you would like, but we will be using wordpress in this guide to keep it simple. You can create the database for WordPress by typing:

CREATE DATABASE your_domain DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci;

Note: Every MySQL statement must end in a semi-colon (;). Check to make sure this is present if you are running into any issues.

Next, we are going to create a separate MySQL user account that we will use exclusively to operate on our new database. Creating one-function databases and accounts is a good idea from a management and security standpoint. We will use the name wordpressuser in this guide. Feel free to change this if you'd like.

We are going to create this account, set a password, and grant access to the database we created. We can do this by typing the following command. Remember to choose a strong password here for your database user:

GRANT ALL ON your_domain.* TO 'wordpressuser'@'localhost' IDENTIFIED BY 'password';

You now have a database and user account, each made specifically for WordPress. We need to flush the privileges so that the current instance of MySQL knows about the recent changes we've made:

FLUSH PRIVILEGES;

Exit out of MySQL by typing:

EXIT;

The MySQL session will exit, returning you to the regular Linux shell.

Step 2 — Installing Additional PHP Extensions

When setting up our LEMP stack, we only required a very minimal set of extensions in order to get PHP to communicate with MySQL. WordPress and many of its plugins leverage additional PHP extensions.

We can download and install some of the most popular PHP extensions for use with WordPress by typing:

sudo apt update
sudo apt install php-curl php-gd php-intl php-mbstring php-soap php-xml php-xmlrpc php-zip

Note: Each WordPress plugin has its own set of requirements. Some may require additional PHP packages to be installed. Check your plugin documentation to discover its PHP requirements. If they are available, they can be installed with apt as demonstrated above.

When you are finished installing the extensions, restart the PHP-FPM process so that the running PHP processor can leverage the newly installed features:

sudo systemctl restart php7.0-fpm

We now have all of the necessary PHP extensions installed on the server.

Step 3 — Configuring Nginx

Next, we will be making a few minor adjustments to our Nginx server block files. Based on the prerequisite tutorials, you should have a configuration file for your site in the /etc/nginx/sites-available/ directory configured to respond to your server's domain name and protected by a TLS/SSL certificate. We'll use /etc/nginx/sites-available/your_domain as an example here, but you should substitute the path to your configuration file where appropriate.

Additionally, we will use /var/www/your_domain as the root directory of our WordPress install. You should use the web root specified in your own configuration.

Note: It's possible you are using the /etc/nginx/sites-available/default default configuration (with /var/www/html as your web root). This is fine to use if you're only going to host one website on this server. If not, it's best to split the necessary configuration into logical chunks, one file per site.

Open your site's Nginx configuration file with sudo privileges to begin:

sudo nano /etc/nginx/sites-available/your_domain

We need to add a few location directives within our main server block. After adding SSL certificates your config may have two server blocks. If so, find the one that contains root /var/www/your_domain and your other location directives and implement your changes there.

Start by creating exact-matching location blocks for requests to /favicon.ico and /robots.txt, both of which we do not want to log requests for.

We will use a regular expression location to match any requests for static files. We will again turn off the logging for these requests and will mark them as highly cacheable since these are typically expensive resources to serve. You can adjust this static files list to contain any other file extensions your site may use:

server {
    . . .

    location = /favicon.ico { log_not_found off; access_log off; }
    location = /robots.txt { log_not_found off; access_log off; allow all; }
    location ~* \.(css|gif|ico|jpeg|jpg|js|png)$ {
        expires max;
        log_not_found off;
    }
    . . .
}

Inside of the existing location / block, we need to adjust the try_files list so that instead of returning a 404 error as the default option, control is passed to the index.php file with the request arguments.

This should look something like this:

server {
    . . .
    location / {
        #try_files $uri $uri/ =404;
        try_files $uri $uri/ /index.php$is_args$args;
    }
    . . .
}

When you are finished, save and close the file.

Now, we can check our configuration for syntax errors by typing:

sudo nginx -t

If no errors were reported, reload Nginx by typing:

sudo systemctl reload nginx

Next, we will download and set up WordPress itself.

Step 4 — Downloading WordPress

Now that our server software is configured, we can download and set up WordPress. For security reasons in particular, it is always recommended to get the latest version of WordPress from their site.

Change into a writable directory and then download the compressed release by typing:

cd /tmp
curl -LO https://wordpress.org/latest.tar.gz

Extract the compressed file to create the WordPress directory structure:

tar xzvf latest.tar.gz

We will be moving these files into our document root momentarily. Before we do that, we can copy over the sample configuration file to the filename that WordPress actually reads:

cp /tmp/wordpress/wp-config-sample.php /tmp/wordpress/wp-config.php

Now, we can copy the entire contents of the directory into our document root. We are using the -a flag to make sure our permissions are maintained. We are using a dot at the end of our source directory to indicate that everything within the directory should be copied, including any hidden files:

sudo cp -a /tmp/wordpress/. /var/www/your_domain

Now that our files are in place, we'll assign ownership them to the www-data user and group. This is the user and group that Nginx runs as, and Nginx will need to be able to read and write WordPress files in order to serve the website and perform automatic updates.

sudo chown -R www-data:www-data /var/www/your_domain

Our files are now in our server's document root and have the correct ownership, but we still need to complete some more configuration.

Step 5 — Setting up the WordPress Configuration File

Next, we need to make some changes to the main WordPress configuration file.

When we open the file, our first order of business will be to adjust some secret keys to provide some security for our installation. WordPress provides a secure generator for these values so that you do not have to try to come up with good values on your own. These are only used internally, so it won't hurt usability to have complex, secure values here.

To grab secure values from the WordPress secret key generator, type:

curl -s https://api.wordpress.org/secret-key/1.1/salt/

You will get back unique values that look something like this:

Warning: It is important that you request unique values each time. Do NOT copy the values shown below!

Output
define('AUTH_KEY',         '1jl/vqfs<XhdXoAPz9 DO NOT COPY THESE VALUES c_j{iwqD^<+c9.k<J@4H');
define('SECURE_AUTH_KEY',  'E2N-h2]Dcvp+aS/p7X DO NOT COPY THESE VALUES {Ka(f;rv?Pxf})CgLi-3');
define('LOGGED_IN_KEY',    'W(50,{W^,OPB%PB<JF DO NOT COPY THESE VALUES 2;y&,2m%3]R6DUth[;88');
define('NONCE_KEY',        'll,4UC)7ua+8<!4VM+ DO NOT COPY THESE VALUES #`DXF+[$atzM7 o^-C7g');
define('AUTH_SALT',        'koMrurzOA+|L_lG}kf DO NOT COPY THESE VALUES  07VC*Lj*lD&?3w!BT#-');
define('SECURE_AUTH_SALT', 'p32*p,]z%LZ+pAu:VY DO NOT COPY THESE VALUES C-?y+K0DK_+F|0h{!_xY');
define('LOGGED_IN_SALT',   'i^/G2W7!-1H2OQ+t$3 DO NOT COPY THESE VALUES t6**bRVFSD[Hi])-qS`|');
define('NONCE_SALT',       'Q6]U:K?j4L%Z]}h^q7 DO NOT COPY THESE VALUES 1% ^qUswWgn+6&xqHN&%');

These are configuration lines that we can paste directly in our configuration file to set secure keys. Copy the output you received now.

Now, open the WordPress configuration file:

sudo nano /var/www/your_domain/wp-config.php

Find the section that contains the dummy values for those settings. It will look something like this:

. . .

define('AUTH_KEY',         'put your unique phrase here');
define('SECURE_AUTH_KEY',  'put your unique phrase here');
define('LOGGED_IN_KEY',    'put your unique phrase here');
define('NONCE_KEY',        'put your unique phrase here');
define('AUTH_SALT',        'put your unique phrase here');
define('SECURE_AUTH_SALT', 'put your unique phrase here');
define('LOGGED_IN_SALT',   'put your unique phrase here');
define('NONCE_SALT',       'put your unique phrase here');

. . .

Delete those lines and paste in the values you copied from the command line:

. . .

define('AUTH_KEY',         'VALUES COPIED FROM THE COMMAND LINE');
define('SECURE_AUTH_KEY',  'VALUES COPIED FROM THE COMMAND LINE');
define('LOGGED_IN_KEY',    'VALUES COPIED FROM THE COMMAND LINE');
define('NONCE_KEY',        'VALUES COPIED FROM THE COMMAND LINE');
define('AUTH_SALT',        'VALUES COPIED FROM THE COMMAND LINE');
define('SECURE_AUTH_SALT', 'VALUES COPIED FROM THE COMMAND LINE');
define('LOGGED_IN_SALT',   'VALUES COPIED FROM THE COMMAND LINE');
define('NONCE_SALT',       'VALUES COPIED FROM THE COMMAND LINE');

. . .

Next, we need to modify some of the database connection settings at the beginning of the file. You need to adjust the database name, the database user, and the associated password that we configured within MySQL.

The other change we need to make is to set the method that WordPress should use to write to the filesystem. Since we've given the web server permission to write where it needs to, we can explicitly set the filesystem method to "direct". Failure to set this with our current settings would result in WordPress prompting for FTP credentials when we perform some actions. This setting can be added below the database connection settings, or anywhere else in the file:

. . .

define('DB_NAME', 'your_domain');

/** MySQL database username */
define('DB_USER', 'wordpressuser');

/** MySQL database password */
define('DB_PASSWORD', 'password');

. . .

define('FS_METHOD', 'direct');

Save and close the file when you are finished.

Step 6 — Completing the Installation Through the Web Interface

Now that the server configuration is complete, we can finish up the installation through the web interface.

In your web browser, navigate to your server's domain name or public IP address:

http://server_domain_or_IP

Select the language you would like to use:

Next, you will come to the main setup page.

Select a name for your WordPress site and choose a username (it is recommended not to choose something like "admin" for security purposes). A strong password is generated automatically. Save this password or select an alternative strong password.

Enter your email address and select whether you want to discourage search engines from indexing your site:

When you click ahead, you will be taken to a page that prompts you to log in:

Once you log in, you will be taken to the WordPress administration dashboard:

Conclusion

WordPress should be installed and ready to use! Some common next steps are to choose the permalinks setting for your posts (can be found in Settings > Permalinks) or to select a new theme (in Appearance > Themes). If this is your first time using WordPress, explore the interface a bit to get acquainted with your new CMS.