How to Install Caddy Web Server on Ubuntu 20.04

Caddy is an open-source web server that supports both static and modern web applications, with automatic HTTPS enabled for all linked domain names. Written in GO, Caddy provides user-friendly configuration directives, allowing it to function as a web server, reverse proxy, or load balancer to serve web applications on your server.

This article guides you through the process of installing Caddy on Ubuntu 20.04 and securely serving web applications.

Prerequisites

Before you begin:

Have an Ubuntu 20.04 server.
Set up a new A record for your domain that points to the server IP address.
Access the server using SSH as a non-root user with sudo privileges.

Install Caddy

Caddy is not included in the default Ubuntu 20.04 APT repositories. However, it can be installed either from source files or by adding the latest repository information to your server. Follow the steps below to download the latest Caddy repository details and install the application on your server.

Add the latest Caddy GPG Key to your server.

                            console
                            
$ curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg

Add the Caddy repository to your APT sources.

                            console
                            
$ curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list

Update the server package index.
console
```
$ sudo apt update
```
Install Caddy.
console
```
$ sudo apt install caddy
```
View the installed Caddy version to verify that the installation is successful.
console
```
$ caddy -v
```
Output:
```
v2.9.1 h1:OEYiZ7DbCzAWVb6TNEkjRcSCRGHVoZsJinoDR/n9oaY=
```
Allow incoming connections to the HTTP port 80 through the firewall.
console
```
$ sudo ufw allow 80
```
Restart the firewall to apply changes.
console
```
$ sudo ufw reload
```
Access your server IP to test access to the Caddy web server.
```
http://SERVER-IP
```
Confirm that the default Caddy webpage displays in your browser.

Manage the Caddy System Service

Enable Caddy to start at boot time.
console
```
$ sudo systemctl enable caddy
```
Start the Caddy web server.
console
```
$ sudo systemctl start caddy
```

View the Caddy system service status to verify that the application is running.

                            console
                            
$ sudo systemctl status caddy

Output:

● caddy.service - Caddy
     Loaded: loaded (/lib/systemd/system/caddy.service; enabled; vendor preset: enabled)
     Active: active (running) since Sun 2025-04-06 09:20:18 UTC; 4min 10s ago
       Docs: https://caddyserver.com/docs/
   Main PID: 3015 (caddy)
      Tasks: 9 (limit: 9415)
     Memory: 10.9M
     CGroup: /system.slice/caddy.service
             └─3015 /usr/bin/caddy run --environ --config /etc/caddy/Caddyfile

Create a Caddy Virtual Host

Caddy stores its configuration files in the /etc/caddy directory by default and allows Caddyfile configurations from any location on your server. Follow the steps below to create a new Caddy virtual host to serve web application files from the /var/www/example.com directory on your server.

Create the /var/www/example.com web application files directory.
console
```
$ sudo mkdir -p /var/www/example.com
```
Create a new HTML application file index.html.
console
```
$ sudo nano /var/www/example.com/index.html
```

Add the following code to the file.

                            html
                            
                        
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Greetings from Vultr!</title>
</head>
<body>
    <br><br><br>
    <h1 style="text-align: center;">Hello World! Greetings from Vultr</h1>
</body>
</html>

Save and close the file.

Switch to the Caddy configuration files directory.
console
```
$ cd /etc/caddy/
```
Back up the default Caddyfile configuration.
console
```
$ sudo mv Caddyfile Caddyfile.default
```
Create a new Caddyfile configuration.
console
```
$ sudo nano Caddyfile
```
Add the following configurations to the file.
ini
```
example.com {
        tls admin@example.com

        root * /var/www/example.com

        file_server {
                index index.html
        }

        log {
                output file /var/log/caddy/example.log
                format console
        }
}
```
Save and exit the file.

The Caddy configuration above creates a new virtual host for your domain example.com. Here’s what each part does:
- example.com: Defines a new virtual host profile using your domain or IP address.
- tls: Associates an email address with Let's Encrypt for SSL certificate generation requests.
- root: Specifies the directory containing the web application files for the virtual host.
- file_server: Enables the file server for serving web application files. The index directive sets the default file to be served when accessing your domain.
- log: Configures logging for access and error details to a specified file, such as /var/log/caddy/example.log.

Test the Caddy configuration for errors.

                            console
                            
$ sudo caddy validate

Output:

...........
2024/06/1 15:19:11.478 INFO    tls.cache.maintenance   started background certificate maintenance      {"cache": "0xc0000e5300"}
2024/06/1 15:19:11.478 INFO    tls.cache.maintenance   stopped background certificate maintenance      {"cache": "0xc0000e5300"}
Valid configuration

Reload the Caddy web server to apply your configuration changes.
console
```
$ sudo caddy reload
```

Secure the Caddy Web Server

Caddy automatically enables HTTPS to secure all connections using SSL certificates for virtual host profiles with valid domains on your server. Follow the steps below to secure the Caddy web server by restricting access to the Caddyfile configurations and preventing unauthorized changes by unintended users.

Grant the Caddy user full privileges to the /etc/caddy directory.
console
```
$ sudo chown -R caddy:caddy /etc/caddy
```
Grant the Caddy user read and write permissions to the Caddyfile while disabling access for other system users.
console
```
$ sudo chmod 660 /etc/caddy/Caddyfile
```

Long list the /etc/caddy directory to verify the permission changes.

                            console
                            
$ ls -l /etc/caddy/

Output:

total 8
-rw-rw---- 1 caddy caddy 168 Jun 2 15:20 Caddyfile
-rw-r--r-- 1 caddy caddy 769 Jun  2 12:07 Caddyfle.default

Set Up Firewall Rules

Caddy uses HTTP port 80 and HTTPS port 443, depending on your Caddyfile configurations, to serve files on the server. Follow the steps below to allow access to both Caddy ports through the firewall and enable network connections to the web server.

View the UFW status and verify that it's active.
console
```
$ sudo ufw status
```
If the status is inactive, allow the SSH port 22 and enable UFW.
console
```
$ sudo ufw allow 22 && sudo ufw enable
```
Allow incoming connections to the HTTPS port 443.
console
```
$ sudo ufw allow 443
```
Reload the firewall to apply changes
console
```
$ sudo ufw reload
```
Access your domain using a browser such as Chrome to verify that Caddy serves your virtual host web application files.
```
https://example.com
```
If you receive a connection error, view the Caddy configuration logs to verify the error details.

Conclusion

You have successfully installed the Caddy web server on your Ubuntu 20.04 server and configured a virtual host profile to serve web application files.

How to Install Caddy Web Server on Ubuntu 20.04

Prerequisites

Install Caddy

Manage the Caddy System Service

Create a Caddy Virtual Host

Secure the Caddy Web Server

Set Up Firewall Rules

Conclusion

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