How to install and configure Caddy, a modern web server, running as a service on CentOS 6.8. You will also obtain a free SSL-Certificate for a website automatically.

This is in-depth guide how to install a modern web server named Caddy as service, that running from regular unprivileged user. You will also obtain a Free SSL-Certificate for a Website automatically.

Why Caddy?

Apache and Nginx are the two most common web servers in the world. Apache is a classical solution, but due to it's memory consumption (because to it's nature of creating a new process for each request) we will leave it for another occasion. Nginx is very fast and the RAM consumption is very-very low, if we need to serve static pages. But Nginx's configuration is not to easy read and understand, this is why we will try more flexible and clear solution, which is more intended for newbies.

Caddy is written is Go, open-source and pretty fast web server. If you're looking for low-memory solution the Caddy Web server is the perfect solution. The Caddy's config file has a very intuitive syntax, where you can ask your web server which static pages to display or which backend to reverse or which route to handle. Additionally Caddy has a distinct advantage over their competitors: it uses HTTPS by default! A few config file yields a fully renewable(!) SSL-Certificate from Let's Encrypt. Caddy is the first web server, that can obtain certificates for you automatically. And that's not all: Certificates are automatically renewed in the background - sounds like magic, isn't it? No CRON scheduling etc. Let's your hands free for other tasks!

Basic Features

TLS. Caddy obtains certificates for you automatically using Let's Encrypt.
Easy configuration with the Caddyfile.
VIRTUAL HOSTS. Serve multiple sites from the same IP address with one Caddy server.
Minify static files on-the-fly. Supports CSS, HTML, JS, JSON, SVG and XML.
HTTP/2. Caddy uses HTTP/2 right out of the box. This will increase the response time of a Website.

and more interesting features, please see the details in the Official Documentation

Preparing for Installation

When you perform any root tasks with the new user, you will need to use the phrase sudo before the command.

Let’s go ahead and edit the sudo configuration. This can be done through the default editor, which in CentOS is vi. Type from root:

$ sudo /usr/sbin/visudo

Then find the section called # User privilege specification Under this section, add the line as below, granting all the permissions to you as a new user (replace regularuser with your real current username). To type in vi, press a.

*# User privilege specification*
root ALL=(ALL) ALL
regularuser ALL=(ALL) ALL

Then find above the line Defaults secure_path=... and let's add to the end of line :/usr/local/bin The line will look like this:

Defaults secure_path = /sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin

Press Escape, then type :w(press enter), :q(press enter)

Done!

To quit from root mode type:

$ su regularuser

You are ready to install new software without to login as root.

Installing

To install simple type the following command:

$ sudo wget -qO- https://getcaddy.com | bash -s http.minify

The Output might look like this:

Downloading Caddy for linux/386... https://caddyserver.com/download/linux/386?plugins=http.minify Extracting... Putting caddy in /usr/local/bin (may require password) Caddy 0.10.3 Successfully installed

Then we need to make any changes to system environment. It's strange, but /usr/local/bin is missing from superuser $PATH. Let's fix this bug:

$ echo 'pathmunge /usr/local/bin' | sudo tee /etc/profile.d/localbin.sh
$ sudo chmod +x /etc/profile.d/localbin.sh

Done!

Setup

In the next step we will create an unprivileged user, which will be used for running Caddy server. This is necessary for security reasons, because running a server as root is the really bad practice.

$ sudo groupadd www-data
$ sudo useradd www-data -d /home/www -g www-data -s /sbin/nologin

In the next few steps we will create a few necessary directories: for caddy config file, log file and for automatic TLS support.(!modified)

$ sudo mkdir -p /etc/caddy
$ sudo touch /etc/caddy/Caddyfile
$ sudo mkdir -p /etc/ssl/caddy | sudo mkdir -p /var/log/caddy

To change the owner of these directories and group too let's type:

$ sudo chown -R www-data:www-data /etc/caddy
$ sudo chown -R www-data:root /etc/ssl/caddy
$ sudo chown -R www-data:www-data /var/log/caddy

We need also to configure Caddy as a service to run at startup. Let's type to download a special CentOS 6 init-script Edition (forked from official init-script):

$ sudo wget -P /etc/init.d https://gist.githubusercontent.com/coocheenin/9d6cd2a0f3a148c24c9f2c6649c63643/raw/87f9dcb3def7ec04d728f7544fcaf3a73294b4f1/caddy

Don't forget to make it executable:

$ sudo chmod +x /etc/init.d/caddy

Whats the difference between this script and official script? The key command, which starts caddy as daemon, is different. Since the command start-stop-daemon is missing in CentOS, daemonize utility was found in replacement.

Let's install with yum utility:

$ sudo yum install -y daemonize

Then we will activate caddy as a service (daemon) and it might be enabled enabled to start on boot:

$ sudo chkconfig --add caddy
$ sudo chkconfig --level 2345 caddy on

Done! Now we can check it like sudo service caddy status. The output will look like this:

caddy is not running

In the next chapter we will try to configure the web server to host a Website.

Organizing and Managing Directories to Host a Website

We will locate the website directory at /home/www location. Let's type to create a folder (web root):

$ sudo mkdir /home/www/site1

Attention! The files in your web root can belong to the caddy user (www-data) otherwise your regular user as long as Caddy has READ permission on all files to be served and EXECUTE permission on all directories.

So if you plan to deploy your pages via SFTP-Client as regular user, we must set the following permissions: (replace regularuser with your real current username)

$ sudo usermod -g www-data regularuser
$ sudo chown -R regularuser:www-data /home/www/site1
$ sudo chmod -R 755 /home/www/site1
$ sudo chmod 750 /home/www

Since you are now the website's owner, feel free to create the test page without sudo using like this:

$ echo '<!doctype html><head><title>Caddy Test Page</title></head><body><h1>Thank You, Matt!</h1></body></html>' >> /home/www/site1/index.htm

Done! In the last chapter below we will configure a web server via Caddyfile.

Configuring

It's the last and the shortest chapter in this guideline. Open the Caddyfile you created above like this:

$ sudo nano /etc/caddy/Caddyfile

Then type the following text section in curly braces:

example.com {
root /home/www/site1
tls [email protected]
minify
}

That's all!

Let's Start

$ sudo service caddy start

Now open your browser and type your domain name with https prefix, like this https://example.com You should see a test page "Thank You, Matt!" with appreciation to the brilliant software creator, Caddy Author, Matt Holt.

Let's see for a green lock symbol in the URL bar. That’s all, you have successfully integrated Let’s Encrypt SSL-Certificate to your Website. Well done!

coocheenin/caddy-install-guide.md