Logging (#1737)

* Logging

* Doing dependency injection

* expose GetLoggers for better testing

Co-authored-by: stas <statis@microsoft.com>

src/ApiService/ApiService/Program.cs

@@ -1,17 +1,41 @@
+using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Azure.Functions.Worker.Configuration;
+using Azure.ResourceManager.Storage.Models;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.OneFuzz.Service;
 
 public class Program
 {
+    public static List<ILog> GetLoggers() {
+        List<ILog> loggers = new List<ILog>();
+        foreach (var dest in EnvironmentVariables.LogDestinations)
+        {
+            loggers.Add(
+                dest switch
+                {
+                    LogDestination.AppInsights => new AppInsights(),
+                    LogDestination.Console => new Console(),
+                    _ => throw new Exception(string.Format("Unhandled Log Destination type: {0}", dest)),
+                }
+            );
+        }
+        return loggers;
+    }
+
+
     public static void Main()
     {
         var host = new HostBuilder()
-            .ConfigureFunctionsWorkerDefaults()
-            .Build();
+        .ConfigureFunctionsWorkerDefaults()
+        .ConfigureServices((context, services) =>
+            services.AddSingleton<LogTracerFactory>(_ => new LogTracerFactory(GetLoggers()))
+        )
+        .Build();
 
         host.Run();
     }