Error Installing a Windows Service (in F#)

Question

my question is the following: When I try to install my Windows Service I get the following error:

snippet: ... No public installers with the RunInstallerAttribute.Yes attribute could be found in the <path to exe> assembly. ...

I follow this tutorial

I have one Program.fs file containing:

[<RunInstaller(true)>]
type public FSharpServiceInstaller() =
    inherit Installer()
    do
        < some logic, doesn't really matter >

This should be sufficient, as a matter of fact, I don't even think I need to add the public keyword to the type definition. Installing this executable with InstallUtil.exe gives me the same error as installing it using the following code:

[<EntryPoint>]
let main args =

    if Environment.UserInteractive then
        let parameter = String.Concat(args);
        match parameter with
        | "-i" -> ManagedInstallerClass.InstallHelper [| Assembly.GetExecutingAssembly().Location |]
        | "-u" -> ManagedInstallerClass.InstallHelper [| "/u"; Assembly.GetExecutingAssembly().Location |]
        | _ -> printf "Not allowed!\n" 
    else 
        ServiceBase.Run [| new CreditToolsService() :> ServiceBase |];
    0

I have tried running this script in PowerShell, cmd and Visual Studio CLI as both administrator and my normal account but I keep getting the same error. If anyone knows what I'm doing wrong I would really appreciate some help.

Answer 1

OK, so here goes...

I've looked at the code provided by user1758475 and just randomly started copy pasting solutions into an application. Don Symes's solution "just worked" and I finally figured out why: I did not (and he does) have a namespace declaration, in my source. Seems like this was the culprit! After I added the namespace the installer worked like a charm.

As Curt Nichols pointed out, the installer should not be in a module because a module effectively hides the type from the calling code.

Thank you for help in figuring this out.

For those of you who want to see a working example:

namespace FileWatcher
open System
open System.Reflection
open System.ComponentModel
open System.Configuration.Install
open System.ServiceProcess
open System.IO
open System.Configuration

type FileWatcherService() =
    inherit ServiceBase(ServiceName = "FileWatcher")

    let createEvent = fun (args: FileSystemEventArgs) -> 
                    printf "%s has been %s\n" args.FullPath (args.ChangeType.ToString().ToLower()) 
                    |> ignore

    override x.OnStart(args) =
        let fsw = new FileSystemWatcher ()
        fsw.Path                    <- "C:\TEMP"
        fsw.NotifyFilter            <- NotifyFilters.LastAccess ||| NotifyFilters.LastWrite ||| NotifyFilters.FileName ||| NotifyFilters.DirectoryName ||| NotifyFilters.CreationTime
        fsw.Filter                  <- "*.txt"
        fsw.EnableRaisingEvents     <- true
        fsw.IncludeSubdirectories   <- true
        fsw.Created.Add(createEvent)

    override x.OnStop() =
        printf "Stopping the FileWatcher service"

[<RunInstaller(true)>]
type public FSharpServiceInstaller() =
    inherit Installer()
    do 

        // Specify properties of the hosting process
        new ServiceProcessInstaller
            (Account = ServiceAccount.LocalSystem)
        |> base.Installers.Add |> ignore

        // Specify properties of the service running inside the process
        new ServiceInstaller
            ( DisplayName = "AAA FileWatcher Service", 
            ServiceName = "AAAFileWatcherService",
            StartType = ServiceStartMode.Automatic )
        |> base.Installers.Add |> ignore


module Program =
    [<EntryPoint>]
    let main args =

        printf "starting the application...\n"


        if Environment.UserInteractive then
            let parameter = String.Concat(args);
            match parameter with
            | "-i" -> ManagedInstallerClass.InstallHelper [| Assembly.GetExecutingAssembly().Location |]
            | "-u" -> ManagedInstallerClass.InstallHelper [| "/u"; Assembly.GetExecutingAssembly().Location |]
            | _ -> printf "Not allowed!\n" 
        else 
            ServiceBase.Run [| new FileWatcherService() :> ServiceBase |];
        0