Securing an unmanaged server with a Let's Encrypt SSL certificate

Let’s Encrypt provides free, automated SSL/TLS certificates that help secure websites with HTTPS. On unmanaged servers (where you control the OS and configuration directly), you can install Let’s Encrypt certificates using command‑line tools such as Certbot.

Why Use Let’s Encrypt?

Free and widely trusted by browsers.
Automates certificate issuance and renewal.
Provides strong encryption for websites and applications.
Helps avoid “Not Secure” browser warnings.

Steps to Secure an Unmanaged Server

1. Install Certbot

Certbot is the recommended client for Let’s Encrypt.

On Ubuntu/Debian:
Terminal window
```
sudo apt update
sudo apt install certbot
```
On CentOS/RHEL:
Terminal window
```
sudo yum install certbot
```

⚠️ Note: Some VPS infrastructures may not support snapd. In that case, use your distribution’s package manager instead of Snap.

2. Generate and Install the SSL Certificate

Run Certbot with your web server type:

Apache:
```
sudo certbot --apache
```
Nginx:
```
sudo certbot --nginx
```

Certbot will automatically configure your server to use HTTPS.

3. Automatic Renewal

Let’s Encrypt certificates are valid for 90 days. Certbot sets up a cron job or systemd timer to renew them automatically:

sudo certbot renew --dry-run

This command tests the renewal process to ensure it works correctly.

4. Verify Installation

Visit your site with https:// and check for the padlock icon.
Use SSL testing tools (e.g., SSL Labs) to confirm proper installation.