How to catch exception and stop Topshelf service?

Question

I have a topshelf windows service where I want to do some checking (i.e. if an xml file exists) and if the check fails I need the windows service to stop.

So I tried doing the check in the Start() method and then raise an exception:

public void Start()
{
    if (!File.Exists(_xmlFile) throw new FileNotFoundException();
    // Do some work here if xml file exists.
}

However, the windows service stays around as a process after the exception which I then have to kill manually in the task manager.

Is there a way to not run the service if certain conditions (i.e. file not found) hold?

Answer 1

I've "borrowed" the sample code for the functional setup of topshelf to demonstrate a point:

HostFactory.Run(x =>                                 //1
    {
        x.Service<TownCrier>(s =>                        //2
        {
           s.ConstructUsing(name=> new TownCrier());     //3
           s.WhenStarted(tc => tc.Start());              //4
           s.WhenStopped(tc => tc.Stop());               //5
        });
        x.RunAsLocalSystem();                            //6

        x.SetDescription("Sample Topshelf Host");        //7
        x.SetDisplayName("Stuff");                       //8
        x.SetServiceName("stuff");                       //9
    });    

You're going to have to place your file system check BEFORE the above code runs. Let's think about this a second. The point of having a service is to make sure it RUNS and KEEPS RUNNING. You're attempting to subvert a basic principle of having service applications in the first place. Instead of trying to stop the service because of the missing file, figure out some way to alert your support staff and NOT do whatever depends on that missing file.