Complete Guide to Create Let’s Encrypt on Linux Server

Let’s Encrypt is a free, automated, and open certificate authority (CA) that provides SSL/TLS certificates for securing websites with HTTPS. By using Let’s Encrypt, you can create Let’s Encrypt certificates for your Linux-based websites without paying for traditional certificates, while still ensuring strong encryption and trustworthiness for your visitors. It is widely used by system administrators, developers, and hosting providers to implement HTTPS affordably and efficiently.

In this article, we’ll walk you through how to create and configure Let’s Encrypt on a Linux server. We’ll cover prerequisites, installation steps, certificate issuance, automatic renewal, integration with popular web servers like Apache and Nginx, troubleshooting, and best practices. By the end, you’ll have a fully working SSL setup using Let’s Encrypt on your Linux environment.

Prerequisites

Before setting up Let’s Encrypt, ensure your system meets these requirements:

• A Linux server (Ubuntu, Debian, CentOS, or RHEL).
• Root or sudo access.
• A domain name pointing to your server’s public IP.
• Web server installed (Apache or Nginx recommended).
• Port 80 (HTTP) and 443 (HTTPS) are open in your firewall.

These prerequisites help avoid errors and ensure a smooth certificate setup.

Create Let’s Encrypt Certificate

Let’s Encrypt makes it easy to secure your Linux server with SSL/TLS certificates at no cost. By using the Certbot tool, you can generate, install, and renew certificates automatically. Below are the steps to create a Let’s Encrypt certificate.

Step 1: Update System Packages

Before installing Let’s Encrypt, update your server packages:

sudo apt update && sudo apt upgrade -y   # Ubuntu/Debian  
sudo yum update -y                       # CentOS/RHEL  

Step 2: Install Certbot

Certbot is the recommended client for managing Let’s Encrypt SSL certificates.

• On Ubuntu/Debian:

sudo apt install certbot python3-certbot-nginx -y

or for Apache:

sudo apt install certbot python3-certbot-apache -y

• On CentOS/RHEL:

sudo yum install certbot python3-certbot-nginx -y

This installs Certbot along with the required plugin for your web server.

Step 3: Obtain SSL Certificate

• For Nginx:

sudo certbot --nginx -d example.com -d www.example.com

• For Apache:

sudo certbot --apache -d example.com -d www.example.com

Certbot will automatically configure your web server and request certificates from Let’s Encrypt.

Step 4: Verify SSL Installation

After installation, visit https://yourdomain.com to confirm HTTPS is working.

Configuring Let’s Encrypt on Linux

After installing Let’s Encrypt, proper configuration ensures your SSL/TLS certificates are applied correctly. Let’s Encrypt certificates and settings can be customized for your needs.

• Configuration Files are located in:

/etc/letsencrypt/

• Key Locations:
  • Certificates: /etc/letsencrypt/live/example.com/fullchain.pem
  • Private Keys: /etc/letsencrypt/live/example.com/privkey.pem
• Manual Configuration: You can configure Nginx or Apache manually by editing their config files and pointing to the certificate and private key locations.

Example for Nginx:

server {
    listen 443 ssl;
    server_name example.com www.example.com;

    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;
}

Automatic Renewal of Certificates

Let’s Encrypt certificates are valid for 90 days. Certbot makes renewal automatic.

• Check Renewal Status

sudo certbot renew --dry-run

• Cron Job for Renewal

Certbot automatically installs a cron job. You can verify it using:

systemctl list-timers | grep certbot

This ensures your SSL certificates renew without downtime.

Securing Apache with Let’s Encrypt on Linux

If you’re running Apache, Certbot can configure SSL automatically.

• Install Certbot Apache plugin:

sudo apt install python3-certbot-apache -y

• Run Certbot for Apache:

sudo certbot --apache -d example.com -d www.example.com

• Test Apache SSL configuration:

sudo apachectl configtest
sudo systemctl restart apache2

Apache will now serve traffic securely with HTTPS enabled.

Securing Nginx with Let’s Encrypt on Linux

For Nginx users, Certbot can also auto-configure SSL.

• Install Certbot Nginx plugin:

sudo apt install python3-certbot-nginx -y

• Run Certbot for Nginx:

sudo certbot --nginx -d example.com -d www.example.com

• Reload Nginx:

sudo systemctl reload nginx

Nginx will automatically redirect HTTP to HTTPS and serve encrypted traffic.

Common Issues and Fixes with Let’s Encrypt on Linux

Even though Certbot simplifies SSL installation, issues may still arise.

• Port 80/443 Blocked → Ensure your firewall allows traffic:

sudo ufw allow 80
sudo ufw allow 443

• Domain Not Resolving → Check DNS settings for your domain.
• Too Many Requests → Let’s Encrypt has rate limits; wait or use the staging server with --staging flag.
• Renewal Errors → Run:

sudo certbot renew --dry-run

Best Practices for Let’s Encrypt on Linux

• Always use the latest version of Certbot.
• Enable HTTP to HTTPS redirection for better security.
• Use strong SSL configurations (disable weak ciphers).
• Regularly monitor logs at /var/log/letsencrypt/.
• For multi-domain or wildcard SSL, use DNS-based validation:

sudo certbot -d "*.example.com" --manual --preferred-challenges dns certonly

• Automate renewals and test them often.

Following these practices ensures your SSL setup is secure and reliable.

FAQs: Create Let’s Encrypt on Linux Server

What is Let’s Encrypt, and why should I create it on Linux?

Let’s Encrypt is a free, automated certificate authority that provides SSL/TLS certificates. By creating Let’s Encrypt on Linux, you enable HTTPS for your websites, ensuring secure data transmission, building user trust, and improving SEO rankings without any cost.

How do I create Let’s Encrypt certificates on Linux?

To create Let’s Encrypt on Linux, install Certbot or a similar ACME client, run the command to generate and verify certificates, and configure your web server (Apache/Nginx) to use them. Certificates can be automatically renewed to maintain continuous HTTPS security.

Can I create Let’s Encrypt for multiple domains on Linux?

Yes. You can create Let’s Encrypt certificates for multiple domains by specifying all domain names when running Certbot. Wildcard certificates are also supported with DNS validation, allowing secure HTTPS for multiple subdomains under a single certificate.

Conclusion

Let’s Encrypt provides a simple, cost-free, and secure way to enable HTTPS on Linux servers. With Certbot, the process of issuing, configuring, and renewing SSL certificates becomes highly automated, making it suitable for production environments. In this guide, we explored installation, configuration, automatic renewal, troubleshooting, and best practices for Apache and Nginx.

By adopting Let’s Encrypt, you can strengthen your website’s security, improve SEO rankings, and gain user trust — all without additional costs. For advanced configurations, wildcard certificates, and troubleshooting tips, always refer to the official Let’s Encrypt documentation.