How To Install Let’s Encrypt SSL With Nginx on CentOS 7

Install Let's Encrypt SSL With Nginx on CentOS 7

In this tutorial, we will show you how to install Let’s Encrypt SSL with Nginx on CentOS 7. For those of you who didn’t know, LetsEncrypt is a free open certificate authority (CA) that provides free certificates for websites and other services. The service, is backed by the Electronic Frontier Foundation, Mozilla, Cisco Systems, and Akamai. Unfortunately, LetsEncrypt.org certificates currently have a 3 month lifetime. This means you’ll need to renew your certificate quarterly for now.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation Let’s Encrypt SSL with Nginx on a CentOS 7 server.


  • A server running one of the following operating systems: CentOS 7.
  • It’s recommended that you use a fresh OS install to prevent any potential issues.
  • SSH access to the server (or just open Terminal if you’re on a desktop).
  • A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, as you can harm your system if you’re not careful when acting as the root.

Install Let’s Encrypt SSL With Nginx on CentOS 7

Step 1. First, let’s start by ensuring your system is up-to-date.

yum clean all
yum -y update

Step 2. Installing Let’s Encrypt SSL on CentOS 7.

In CentOS 7, you can find Certbot on the EPEL repository; if you enable it, just install what you need:

yum install epel-release
yum install certbot

You will also need to have Nginx installed and running. Of course, if you are adding certificates onto a previously configured web host this would already be installed:

yum install nginx
systemctl start nginx

The first step to installing let’s encrypt SSL on CentOS Linux is to add a simple configuration inside your Nginx virtual host configuration. Add this line to your vhost configuration:

  location ~ /.well-known {
  allow all;

Save and exit to apply changes:

nginx -t
systemctl restart nginx

Obtaining a certificate with Certbot:

Run the command as you see below, replace “idroot.us” with your real domain name and /var/www/idroot.us with your real webroot path:

certbot certonly -a webroot --webroot-path=/var/www/idroot.us -d idroot.us -d www.idroot.us


[root@idroot.us:~]certbot certonly -a webroot --webroot-path=/var/www/idroot.us -d idroot.us -d www.idroot.us
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Obtaining a new certificate
Performing the following challenges:
http-01 challenge for idroot.us
Using the webroot path /var/www/html for all unmatched domains.
Waiting for verification...
Cleaning up challenges
Generating key (2048 bits): /etc/letsencrypt/keys/0001_key-certbot.pem
Creating CSR: /etc/letsencrypt/csr/0001_csr-certbot.pem
 - Congratulations! Your certificate and chain have been saved at
   /etc/letsencrypt/live/idroot.us/fullchain.pem. Your cert
   will expire on 2017-07-16. To obtain a new or tweaked version of
   this certificate in the future, simply run certbot again. To
   non-interactively renew *all* of your certificates, run "certbot
 - If you like Certbot, please consider supporting our work by:

   Donating to ISRG / Let's Encrypt:   https://letsencrypt.org/donate
   Donating to EFF:                    https://eff.org/donate-le

Step 3. Configure Let’s Encrypt TLS/SSL on Nginx Web Server.

First, edit the Virtual Host file you specified during configuration through Certbot and add these three directives:

listen 443 ssl http2;
ssl_certificate /etc/letsencrypt/live/idroot.us/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/idroot.us/privkey.pem;

The full Nginx vhost configuration may look like this:

server {
     listen 80;
     server_name idroot.us www.idroot.us;
     rewrite ^(.*) https://idroot.us$1 permanent;

server {
     access_log off;
     log_not_found off;
     error_log  logs/idroot.us-error_log warn;

    server_name  idroot.us; 
    root   /var/www/idroot.us;
    index  index.php index.html index.htm;

    listen 443 ssl http2;
    ssl_certificate /etc/letsencrypt/live/idroot.us/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/idroot.us/privkey.pem;

  ## Stuff required by certbot
     location ~ /.well-known {
     allow all;

  ## SSL
   ssl_session_cache shared:SSL:20m;
   ssl_session_timeout 10m;

   ssl_prefer_server_ciphers On;
   ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

   ssl_stapling on;
   ssl_stapling_verify on;
   resolver valid=300s;
   resolver_timeout 10s;

   access_log /var/www/idroot.us/logs/access.log;
   error_log /var/www/idroot.us/logs/error.log;

   # php-script handler
   location ~ \.php$ {
      fastcgi_index index.php;
      fastcgi_pass;       fastcgi_read_timeout 150;
      root    /var/www/idroid.us/public_html;
      fastcgi_param SCRIPT_FILENAME /var/www/idroot.us$fastcgi_script_name;
      include /etc/nginx/fastcgi_params;
 location  ~ /\.ht {
               deny  all;

Step 5. Set Up Let’s Encrypt SSL Auto-Renewal.

We will add a cronjob to run the renewal command every week, run this command:

export VISUAL=nano; crontab -e

Paste the following lines:

01 1 * * 0 /usr/bin/certbot renew >> /var/log/ssl-renew.log 
06 1 * * 0 /usr/bin/systemctl nginx reload

Save and Exit from the crontab table.

This will create a new cron job that will be executed every Sunday at 01 AM, and then it will reload the Nginx webserver to apply the changes. The output will be logged into /var/log/ssl-renew.log file for further analysis if needed.

Congratulations! You have successfully installed Let’s Encrypt. Thanks for using this tutorial for installing Let’s Encrypt SSL on CentOS 7 system. For additional help or useful information, we recommend you check the official Let’s Encrypt website.

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r00t is a seasoned Linux system administrator with a wealth of experience in the field. Known for his contributions to idroot.us, r00t has authored numerous tutorials and guides, helping users navigate the complexities of Linux systems. His expertise spans across various Linux distributions, including Ubuntu, CentOS, and Debian. r00t's work is characterized by his ability to simplify complex concepts, making Linux more accessible to users of all skill levels. His dedication to the Linux community and his commitment to sharing knowledge makes him a respected figure in the field.
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