How to install Caddy Web Server on CentOS 7

Caddy web server is an open source, HTTP/2 enabled web server written in Go language. One of the most notable features of Caddy is automatic enabling TLS for hosted websites. Caddy automatically acquires and renew TLS certificates from Let's Encrypt. Caddy can also be configured as the reverse proxy server. Caddy is distributed under Apache 2 license.

In this article, we are installing Caddy web server on CentOS 7 and configure HTTP and HTTPS websites on Caddy.

 

Table of Contents:

• Features of Caddy Web Server
• Environment Specification
• Installing Caddy Web Server on CentOS 7
• Creating directory structure for Caddy Web Server
• Create Systemd service for Caddy on CentOS 7
• Create a Server Block in Caddyfile
• Configuring Automatic TLS on Caddy Web Server

 

Features of Caddy Web Server:

Some of the famous features of Caddy web server are:

• HTTP/1.1 and HTTP/2
• HTTPS with automatic TLS
• Virtual Hosting
• Native IPv4 and IPv6 support
• Reverse Proxy
• Load Balancing with Health checks
• GZip compression

Environment Specification:

We have provisioned a CentOS 7 virtual machine with following specifications:

• CPU - 3.4 Ghz (1 Core)
• Memory - 1 GB
• Storage - 20 GB
• Operating System - CentOS 7.7
• Hostname - caddy-01.example.com
• IP Address - 192.168.116.206 /24

 

Installing Caddy Web Server on CentOS 7:

Connect with caddy-01.example.com using ssh as root user.

Install latest stable release of Caddy web server using following command.

# curl https://getcaddy.com | bash -s personal
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  7380  100  7380    0     0   4430      0  0:00:01  0:00:01 --:--:--  4432
Downloading Caddy for linux/amd64 (personal license)...
Download verification OK
Extracting...
Putting caddy in /usr/local/bin (may require password)
Caddy v1.0.3 (h1:i9gRhBgvc5ifchwWtSe7pDpsdS9+Q0Rw9oYQmYUTw1w=)
Successfully installed

We are installing Caddy web server - Personal edition here.

If you wish to download commercial version of Caddy web server then, you have to provide Account ID and API Key as describes at Caddy's download page.

Locate installation directory of Caddy web server.

# whereis caddy
caddy: /usr/local/bin/caddy

Unlike Apache and Nginx; Caddy web server does not create configuration files, systemd service and dedicated user to own Caddy service and files.

Therefore, we have to manually create a user for Caddy web server.

# adduser -r -s /sbin/nologin -d /var/www caddy

Here, we are creating

1. a system user using -r parameter
2. with /sbin/nologin shell and
3. the default home directory set to /var/www.

 

Creating directory structure for Caddy Web Server:

Caddy's installation process does not create necessary directories, therefore, we have to manually create these directories and set appropriate permissions.

Create a configuration directory for Caddy web server.

# mkdir /etc/caddy
# chown -R root:caddy /etc/caddy
# touch /etc/caddy/Caddyfile

Caddy web server automatically obtains SSL certificate from Let's Encrypt, and it requires following directory to store that SSL certificate.

# mkdir /etc/ssl/caddy
# chown -R caddy:root /etc/ssl/caddy
# chmod o-rwx /etc/ssl/caddy/

Create the directory to host websites on Caddy web server.

# mkdir /var/www
# chown caddy:caddy /var/www

 

Create Systemd service for Caddy on CentOS 7:

As you have notice that the installation and configuration of Caddy web server on CentOS 7 is not an automated process and we are creating each file/directory and adjusting permissions for the same.

Similarly, we are required to create a system service to automatically run Caddy web server in daemon mode.

Luckily, official Caddy repository provide a Caddy system unit file, that we can use to create a systemd service on CentOS 7.

Instead of using the actual file, we have derived a simpler version of our own.

# vi /usr/lib/systemd/system/caddy.service

and add following lines of code therein.

[Unit]
Description=Caddy HTTP/2 web server
Documentation=https://caddyserver.com/docs
After=network-online.target
Wants=network-online.target systemd-networkd-wait-online.service

[Service]
Restart=on-abnormal

StartLimitIntervalSec=14400
StartLimitBurst=10

User=caddy
Group=caddy

Environment=CADDYPATH=/etc/ssl/caddy

ExecStart=/usr/local/bin/caddy -log stdout -agree=true -conf=/etc/caddy/Caddyfile -root=/var/tmp
ExecReload=/bin/kill -USR1 $MAINPID

KillMode=mixed
KillSignal=SIGQUIT
TimeoutStopSec=5s

LimitNOFILE=1048576
LimitNPROC=512

PrivateTmp=true
PrivateDevices=false
ProtectHome=true
ProtectSystem=full
ReadWritePaths=/etc/ssl/caddy
ReadWriteDirectories=/etc/ssl/caddy

[Install]
WantedBy=multi-user.target

 

Create a Server Block in Caddyfile:

Configure Caddyfile and create a simple server block.

# vi /etc/caddy/Caddyfile

Add following directives to add an HTTP server block.

http:// {
    root /var/www
    gzip
}

Create an index page for our website.

# vi /var/www/index.html

add following code in this file.

<html>
<head><title>Hello World</title>
<body><h1>Hello World</h1></body>
</html>

Enable and start caddy.service.

# systemctl enable --now caddy.service
Created symlink from /etc/systemd/system/multi-user.target.wants/caddy.service to /usr/lib/systemd/system/caddy.service.

Allow http service in CentOS 7 firewall.

# firewall-cmd --permanent --add-service=http
success
# firewall-cmd --reload
success

Open URL http://caddy-01.example.com in a web browser.

If configurations are correct then it will display the 'Hello World' webpage.

 

Configuring Automatic TLS on Caddy Web Server:

Automatic TLS is the distinct feature of Caddy web server that distinguishes Caddy from other web servers.

If automatic TLS is configured, then Caddy web server automatically request and renew the TLS certificates from Let's Encrypt (a free, automated and open certificate authority).

Edit Caddyfile to configure automatic TLS.

# vi /etc/caddy/Caddyfile

and add another server block.

caddy-01.example.com {
    root /var/www
    gzip
    tls ahmer@example.com
}

Here,

1. caddy-01.example.com must be a registered domain and accessible over the Internet.
2. tls directive will inform the Caddy service to acquire a TLS certificate from Let's Encrypt and start the service on default https port 443.

Allow https service in CentOS 7 firewall.

# firewall-cmd --permanent --add-service=https
success
# firewall-cmd --reload
success

Restart Caddy service to load changes.

# systemctl restart caddy.service

Open URL https://caddy-01.example.com in a web browser.

If configurations are correct then it will display the same  'Hello World' webpage but over https protocol this time.

We have successfully installed Caddy web server on CentOS 7 and publish HTTP and HTTPS websites using Caddy.