New: /ping endpoint for verifying that Sonarr is running and able to access it's DB

Closes #4766

src/Sonarr.Http/Authentication/AuthenticationService.cs

@@ -166,6 +166,11 @@ namespace Sonarr.Http.Authentication
             {
                 return true;
             }
+            
+            if (context.Request.IsPingRequest())
+            {
+                return true;
+            }
 
             if (ValidUser(context))
             {

src/Sonarr.Http/Extensions/RequestExtensions.cs

@@ -18,6 +18,11 @@ namespace Sonarr.Http.Extensions
             return request.Path.StartsWith("/feed/", StringComparison.InvariantCultureIgnoreCase);
         }
 
+        public static bool IsPingRequest(this Request request)
+        {
+            return request.Path.StartsWith("/ping", StringComparison.InvariantCultureIgnoreCase);
+        }
+
         public static bool IsSignalRRequest(this Request request)
         {
             return request.Path.StartsWith("/signalr/", StringComparison.InvariantCultureIgnoreCase);

src/Sonarr.Http/Ping/PingModule.cs

@@ -0,0 +1,41 @@
+using System;
+using Nancy;
+using NzbDrone.Core.Configuration;
+using NzbDrone.Http.Ping;
+using Sonarr.Http.Extensions;
+
+namespace NzbDrone.Http
+{
+    public class PingModule : NancyModule
+    {
+        private readonly IConfigRepository _configRepository;
+
+        public PingModule(IConfigRepository configRepository)
+        {
+            _configRepository = configRepository;
+
+            Get("/ping", x => GetStatus());
+        }
+
+        private Response GetStatus()
+        {
+            try
+            {
+                _configRepository.All();
+            }
+            catch (Exception e)
+            {
+                return new PingResource
+                       {
+                           Status = "Error",
+                           Message = e.Message
+                       }.AsResponse(Context, HttpStatusCode.InternalServerError);
+            }
+
+            return new PingResource
+                   {
+                       Status = "OK"
+                   }.AsResponse(Context, HttpStatusCode.OK);
+        }
+    }
+}

src/Sonarr.Http/Ping/PingResource.cs

@@ -0,0 +1,8 @@
+namespace NzbDrone.Http.Ping
+{
+    public class PingResource
+    {
+        public string Status { get; set; }
+        public string Message { get; set; }
+    }
+}