Use Pulumi to provision and Nix to configure (#12)

PulumiWebServer/Local.fs

@@ -1,19 +1,12 @@
 namespace PulumiWebServer
 
-open System.Diagnostics
+open Pulumi
+open Pulumi.Command.Local
 
 [<RequireQualifiedAccess>]
 module Local =
-    let forgetKey (address : Address) : unit =
-        let address = address.Get ()
-        let psi = ProcessStartInfo "/usr/bin/ssh-keygen"
-        psi.Arguments <- $"-R {address}"
-        psi.RedirectStandardError <- true
-        psi.RedirectStandardOutput <- true
-        psi.UseShellExecute <- false
-        let proc = psi |> Process.Start
-        proc.WaitForExit ()
-        let error = proc.StandardOutput.ReadToEnd ()
-        // We don't expect to have configured SSH yet, so this is fine.
-        if proc.ExitCode <> 0 then
-            failwith $"Unexpectedly failed to forget key: {address} ({proc.ExitCode}). {error}"
+    let forgetKey (address : string) : Command =
+        let args = CommandArgs ()
+        args.Create <- Input.lift $"/usr/bin/ssh-keygen -R {address} || exit 0"
+
+        Command ($"forget-key-{address}", args)