Securing your website with SSL certificates is essential for protecting user data and enhancing trust. On an Unmanaged Virtual Private Server (VPS), installing Let's Encrypt SSL certificates requires specific procedures based on your operating system and the presence of a control panel like cPanel.

Installing Let's Encrypt SSL on cPanel VPS

For VPS instances utilizing cPanel, the integration of Let's Encrypt is streamlined through AutoSSL. Follow these steps:

1. Access the VPS via SSH:

   • Log in as the root user or a user with sudo privileges.

2. Install the Let's Encrypt AutoSSL Provider:

• Execute the command:
  /scripts/install_lets_encrypt_autossl_provider
• This command installs the Let's Encrypt plugin for AutoSSL.

1. Configure AutoSSL in WHM:

   • Navigate to Home > SSL/TLS > Manage AutoSSL.
   • Select "Let's Encrypt" as the AutoSSL provider.
   • Agree to the terms of service and save the configuration.

2. Issue SSL Certificates:

   • To issue certificates for all users, use the "Run AutoSSL For All Users" feature.
   • For individual users, select "Manage Users" and proceed accordingly.

Installing Let's Encrypt SSL on CentOS 6 without a Control Panel

For systems without a control panel, Certbot facilitates the installation of Let's Encrypt certificates.

1. Access the VPS via SSH:

   Log in as the root user or a user with sudo privileges.

2. Download and Install Certbot:

   Execute the following commands:
    

1. wget https://dl.eff.org/certbot-auto
   sudo mv certbot-auto /usr/local/bin/certbot-auto
   sudo chown root /usr/local/bin/certbot-auto
   sudo chmod 0755 /usr/local/bin/certbot-auto

    

    
   These commands download Certbot and set the appropriate permissions.

1. Obtain and Install the SSL Certificate:
    

For Apache servers:

• To ensure certificates renew automatically, add a cron job

This schedules the renewal process to run twice daily.

Installing Let's Encrypt SSL on CentOS 7 without a Control Panel

The procedure for CentOS 7 differs slightly due to the availability of the Extra Packages for Enterprise Linux (EPEL) repository.

1. Access the VPS via SSH:

   Log in as the root user or a user with sudo privileges.

2. Enable the EPEL Repository:

   Execute:
    

   sudo yum install epel-release

    
   This command enables access to additional packages required for Certbot.

3. Install Certbot:

   For Apache servers:
    

   sudo yum install certbot python2-certbot-apache

    
   For Nginx servers:
    

   sudo yum install certbot python2-certbot-nginx

    
   These commands install Certbot along with the necessary web server plugins.

4. Obtain and Install the SSL Certificate:

   For Apache:
    

   sudo certbot --apache

    
   For Nginx:
    

   sudo certbot --nginx

    
   Proceed through the interactive prompts to configure your SSL certificates.

5. Set Up Automatic Renewal:

   Add the following cron job to automate renewals:
    

   

    
   This ensures that Certbot attempts to renew the certificates at regular intervals.