Log calls to deprecated endpoints

(cherry picked from commit aaaf18aec33dc0ae5075b53ab81812743608d6a6)

src/Radarr.Http/REST/RestController.cs

@@ -7,6 +7,8 @@ using FluentValidation.Results;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.Controllers;
 using Microsoft.AspNetCore.Mvc.Filters;
+using NLog;
+using NzbDrone.Common.Instrumentation;
 using NzbDrone.Core.Datastore;
 using Radarr.Http.REST.Attributes;
 using Radarr.Http.Validation;
@@ -17,6 +19,9 @@ namespace Radarr.Http.REST
         where TResource : RestResource, new()
     {
         private static readonly List<Type> VALIDATE_ID_ATTRIBUTES = new List<Type> { typeof(RestPutByIdAttribute), typeof(RestDeleteByIdAttribute) };
+        private static readonly Type DEPRECATED_ATTRIBUTE = typeof(ObsoleteAttribute);
+
+        private readonly Logger _logger;
 
         protected ResourceValidator<TResource> PostValidator { get; private set; }
         protected ResourceValidator<TResource> PutValidator { get; private set; }
@@ -32,6 +37,8 @@ namespace Radarr.Http.REST
 
         protected RestController()
         {
+            _logger = NzbDroneLogger.GetLogger(this);
+
             PostValidator = new ResourceValidator<TResource>();
             PutValidator = new ResourceValidator<TResource>();
             SharedValidator = new ResourceValidator<TResource>();
@@ -90,6 +97,13 @@ namespace Radarr.Http.REST
                 }
             }
 
+            var controllerAttributes = descriptor.ControllerTypeInfo.CustomAttributes;
+            if (controllerAttributes.Any(x => x.AttributeType == DEPRECATED_ATTRIBUTE) || attributes.Any(x => x.AttributeType == DEPRECATED_ATTRIBUTE))
+            {
+                _logger.Warn("API call made to deprecated endpoint from {0}", Request.Headers.UserAgent.ToString());
+                Response.Headers["Deprecation"] = "true";
+            }
+
             base.OnActionExecuting(context);
         }