Learn How To Install and Configure Caddy on CentOS 7

September 13, 2019

Table of Contents

Introduction

Caddy is an emerging web server program with native support for HTTP/2 and automatic HTTPS. With ease of use and security in mind, Caddy can be used to rapidly deploy an HTTPS-enabled site with a single config file.

Prerequisites

  • A fresh IT Web Services CentOS 7 x64 server instance. We will use 203.0.113.1 as an example.
  • A sudo user.

    • https://www.itweb.services/tutorials/linux-guides/how-to-update-centos-7-ubuntu-16-04-and-debian-8″>updated to the latest stable status using the EPEL YUM repo.

    https://www.itweb.services/tutorials/linux-guides/introduction-to-itweb.services-dns”>IT Web Services tutorial.

Step 1: Install the Latest Stable Release of Caddy

On a Linux, Mac, or BSD operating system, use the following command to install the latest stable system-specific release of Caddy:

curl https://getcaddy.com | bash

When prompted, input your sudo password to finish the installation.

The Caddy binary will be installed to the /usr/local/bin directory. Use the following command to confirm:

which caddy

The output shoud be:

/usr/local/bin/caddy

For security purposes, NEVER run the Caddy binary as root. In order to give Caddy the ability to bind to privileged ports (e.g. 80, 443) as a non-root user, you need to run the setcap command as follows:

sudo setcap 'cap_net_bind_service=+ep' /usr/local/bin/caddy

Step 2: Configure Caddy

Create a dedicated system user: caddy and a group of the same name for Caddy:

sudo useradd -r -d /var/www -M -s /sbin/nologin caddy

Note: The user caddy created here can only be used to manage the Caddy service and cannot be used for logging in.

Create the home directory /var/www for the Caddy web server, and the home directory /var/www/example.com for your site:

sudo mkdir -p /var/www/example.com
sudo chown -R caddy:caddy /var/www

Create a directory to store SSL certificates:

sudo mkdir /etc/ssl/caddy
sudo chown -R caddy:root /etc/ssl/caddy
sudo chmod 0770 /etc/ssl/caddy

Create a dedicated directory to store the Caddy config file Caddyfile:

sudo mkdir /etc/caddy
sudo chown -R root:caddy /etc/caddy

Create the Caddy config file named Caddyfile:

sudo touch /etc/caddy/Caddyfile
sudo chown caddy:caddy /etc/caddy/Caddyfile
sudo chmod 444 /etc/caddy/Caddyfile
cat <<EOF | sudo tee -a /etc/caddy/Caddyfile
example.com {
    root /var/www/example.com
    gzip
    tls admin@example.com
}
EOF

Note: The Caddyfile file created above is only a basic configuration for running a static website. You can learn more about how to write a Caddyfile here.

In order to facilitate the operations of Caddy, you can setup a systemd unit file for Caddy and then use systemd to manage Caddy.

Use the vi editor to create the Caddy systemd unit file:

sudo vi /etc/systemd/system/caddy.service

Populate the file:

[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
; User and group the process will run as.
User=caddy
Group=caddy
; Letsencrypt-issued certificates will be written to this directory.
Environment=CADDYPATH=/etc/ssl/caddy
; Always set "-root" to something safe in case it gets forgotten in the Caddyfile.
ExecStart=/usr/local/bin/caddy -log stdout -agree=true -conf=/etc/caddy/Caddyfile -root=/var/tmp
ExecReload=/bin/kill -USR1 $MAINPID
; Use graceful shutdown with a reasonable timeout
KillMode=mixed
KillSignal=SIGQUIT
TimeoutStopSec=5s
; Limit the number of file descriptors; see `man systemd.exec` for more limit settings.
LimitNOFILE=1048576
; Unmodified caddy is not expected to use more than that.
LimitNPROC=512
; Use private /tmp and /var/tmp, which are discarded after caddy stops.
PrivateTmp=true
; Use a minimal /dev
PrivateDevices=true
; Hide /home, /root, and /run/user. Nobody will steal your SSH-keys.
ProtectHome=true
; Make /usr, /boot, /etc and possibly some more folders read-only.
ProtectSystem=full
; … except /etc/ssl/caddy, because we want Letsencrypt-certificates there.
;   This merely retains r/w access rights, it does not add any new. Must still be writable on the host!
ReadWriteDirectories=/etc/ssl/caddy
; The following additional security directives only work with systemd v229 or later.
; They further retrict privileges that can be gained by caddy. Uncomment if you like.
; Note that you may have to add capabilities required by any plugins in use.
;CapabilityBoundingSet=CAP_NET_BIND_SERVICE
;AmbientCapabilities=CAP_NET_BIND_SERVICE
;NoNewPrivileges=true
[Install]
WantedBy=multi-user.target

Save and quit:

:wq!

Start the Caddy service and make it automatically start on system boot:

sudo systemctl daemon-reload
sudo systemctl start caddy.service
sudo systemctl enable caddy.service

Step 3: Modify firewall rules

In order to allow visitors to access your Caddy site, you need to open ports 80 and 443:

sudo firewall-cmd --permanent --zone=public --add-service=http 
sudo firewall-cmd --permanent --zone=public --add-service=https
sudo firewall-cmd --reload

Step 4: Create a test page for your site

Use the following command to create a file named index.html in your Caddy site home directory:

echo '<h1>Hello World!</h1>' | sudo tee /var/www/example.com/index.html

Restart the Caddy service to load new contents:

sudo systemctl restart caddy.service

Finally, point your web browser to http://example.com or https://example.com. You should see the message Hello World! as expected.

Need help?

Do you need help setting up this on your own service?
Please contact us and we’ll provide you the best possible quote!