How to install Let’s Encrypt SSL on CentOS 7 with Apache

Step 1 – Installing the Certbot

Install CentOS 7 EPEL repository

# yum install epel-release

Install all of the required packages

# yum install certbot python2-certbot-apache mod_ssl 

Step 2 – Obtaining a Certificate

Obtain a certificate that covers only a single domain

# certbot --apache -d domain.com

Obtain a single certificate that covers multiple domains or subdomains

# certbot --apache -d domain.com -d domain2.com

# certbot --apache -d domain.com -d www.domain.com

Step 3 – Setting Up Auto Renewal

Edit the crontab to create a new job that will run the renewal twice per day. To edit the crontab for the root user

# crontab -e

Enter insert mode by pressing i and add in the following line:

* */12 * * * /usr/bin/certbot renew >/dev/null 2>&1

Now, press Esc to leave insert mode, then :wq and ENTER to save and exit the file.