Run ServiceStack as a daemon on Linux

When your web application is predominantly javascript with a REST service at the back-end there are many reasons why you might want to simply serve the static content through apache (or alternative) and run the service as a ...well... service. Some examples are:

Fortunately this is quite simple.

Service example​

The earlier example of self hosting provides a good starting point, but needs to be modified slightly if running as a daemon.

using System;
using System.Reflection;
using Mono.Unix;
using Mono.Unix.Native;

using Funq;
using ServiceStack;

namespace ServiceStackExample
{
	public class AppHost : AppSelfHostBase
	{
		public AppHost() : base("Example", typeof(AppHost).Assembly) {}

		public override void Configure(Container container) {}
	}
	
	class Program
	{
		static void Main(string[] args)
		{
			//Initialize app host
			var appHost = new AppHost();
			appHost.Init();
			appHost.Start("http://127.0.0.1:8080/");

			UnixSignal[] signals = new UnixSignal[] { 
				new UnixSignal(Signum.SIGINT), 
				new UnixSignal(Signum.SIGTERM), 
			};

			// Wait for a unix signal
			for (bool exit = false; !exit; )
			{
				int id = UnixSignal.WaitAny(signals);

				if (id >= 0 && id < signals.Length)
				{
					if (signals[id].IsSet) exit = true;
				}
			}
		}
	}
}

Be aware that this makes use of posix functionality and will therefore not work under Windows. You will need to add the Mono.Posix library to your project references.

Daemonising the application​

As it stands the project produces a console application that responds to unix signals (press ctrl-c to exit if you are running it from a terminal). If your target platform is Ubuntu then the simplest way to automatically run your application as a daemon is to use an upstart script.

Create the following at /etc/init/example.conf

# ServiceStack Example Application

description "ServiceStack Example"
author      "ServiceStack"

start on started rc
stop on stopping rc

respawn

exec start-stop-daemon --start -c username --exec mono /path/to/application.exe

Ideally we would start the service when apache is ready but apache does not yet emit upstart events. Additional conditions could include a database dependency if required, for example "start on started mysql". Replace "username" with that of an unprivileged user on the system; this avoids the dangers of running the application as root.

You should now be able to start your application with

$ sudo start example

and access the default service information by visiting http://127.0.0.1:8080 in your browser of choice.

Configuring apache​

The following example configuration uses proxying to expose the REST service through apache, so you must ensure that mod_proxy has been enabled first:

$ sudo a2enmod proxy

Next create a file at /etc/apache2/sites-available/example

ProxyPass /api http://127.0.0.1:8080/ retry=0 max=50
ProxyPassReverse /api http://127.0.0.1:8080/

<VirtualHost *:80>
	DocumentRoot /path/to/static/content/

	<Directory />
	</Directory>

	<Directory /path/to/static/content/>
		Options Indexes MultiViews
		AllowOverride None
		Order allow,deny
		allow from all
	</Directory>
</VirtualHost>

Your site can then be enabled with

$ sudo a2ensite example

although you will need to disable the default sites if they are enabled. After restarting/reloading apache you should find your static content at http://127.0.0.1 and the REST service at http://127.0.0.1/api.

Alternative nginx configuration​

Create a file at /etc/nginx/sites-available/example

server {
	listen 80;
	root /path/to/static/content;
	index index.html;

	location /api/ {
		proxy_pass http://127.0.0.1:8080/;
	}
}

To enable the site simply symlink from sites-available to sites-enabled (nginx does not have an equivalent a2ensite tool) and then restart/reload nginx. (N.B. The trailing forward slash on the proxy pass URL is important).

Other hosting options on Linux / Mono​

This StackOverflow answer lists the different options for hosting ServiceStack on Linux with Mono.

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