Add support for CORS (#1377)

src/Microsoft.Diagnostics.Monitoring.RestServer/CorsConfiguration.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Microsoft.Diagnostics.Monitoring.RestServer
+{
+    public class CorsConfiguration
+    {
+        public string AllowedOrigins { get; set; }
+
+        public string[] GetOrigins() => AllowedOrigins?.Split(';');
+    }
+}

src/Tools/dotnet-monitor/Startup.cs

@@ -72,6 +72,13 @@ namespace Microsoft.Diagnostics.Monitoring
                 app.UseHsts();
             }
 
+            CorsConfiguration corsConfiguration = new CorsConfiguration();
+            Configuration.Bind(nameof(CorsConfiguration), corsConfiguration);
+            if (!string.IsNullOrEmpty(corsConfiguration.AllowedOrigins))
+            {
+                app.UseCors(builder => builder.WithOrigins(corsConfiguration.GetOrigins()).AllowAnyHeader().AllowAnyMethod());
+            }
+
             app.UseResponseCompression();
             app.UseMvc();
         }