working on region clearing cache, if using cachemanager back plance this would clear all servers in cluster

src/Ocelot/Cache/IOcelotCache.cs

@@ -1,11 +1,13 @@
 using System;
+using System.Collections.Generic;
 
 namespace Ocelot.Cache
 {
     public interface IOcelotCache<T>
     {
-        void Add(string key, T value, TimeSpan ttl);
-        void AddAndDelete(string key, T value, TimeSpan ttl);
+        void Add(string key, T value, TimeSpan ttl, string region);
+        void AddAndDelete(string key, T value, TimeSpan ttl, string region);
         T Get(string key);
+        void ClearRegion(string region);
     }
 }

src/Ocelot/Cache/Middleware/OutputCacheMiddleware.cs

@@ -63,7 +63,9 @@ namespace Ocelot.Cache.Middleware
 
             var response = HttpResponseMessage;
 
-            _outputCache.Add(downstreamUrlKey, response, TimeSpan.FromSeconds(DownstreamRoute.ReRoute.FileCacheOptions.TtlSeconds));
+            var region = $"{DownstreamRoute.ReRoute.UpstreamHttpMethod}-{DownstreamRoute.ReRoute.UpstreamPathTemplate.Value}";
+
+            _outputCache.Add(downstreamUrlKey, response, TimeSpan.FromSeconds(DownstreamRoute.ReRoute.FileCacheOptions.TtlSeconds), region);
 
             _logger.LogDebug("finished response added to cache for {downstreamUrlKey}", downstreamUrlKey);
         }

src/Ocelot/Cache/OcelotCacheManagerCache.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using CacheManager.Core;
 
 namespace Ocelot.Cache
@@ -6,18 +8,21 @@ namespace Ocelot.Cache
     public class OcelotCacheManagerCache<T> : IOcelotCache<T>
     {
         private readonly ICacheManager<T> _cacheManager;
+        private HashSet<string> _keys;
 
         public OcelotCacheManagerCache(ICacheManager<T> cacheManager)
         {
             _cacheManager = cacheManager;
+            _keys = new HashSet<string>();
         }
 
-        public void Add(string key, T value, TimeSpan ttl)
+        public void Add(string key, T value, TimeSpan ttl, string region)
         {
-            _cacheManager.Add(new CacheItem<T>(key, value, ExpirationMode.Absolute, ttl));
+            _cacheManager.Add(new CacheItem<T>(key, region, value, ExpirationMode.Absolute, ttl));
+            _keys.Add(key);
         }
 
-        public void AddAndDelete(string key, T value, TimeSpan ttl)
+        public void AddAndDelete(string key, T value, TimeSpan ttl, string region)
         {
             var exists = _cacheManager.Get(key);
 
@@ -26,12 +31,17 @@ namespace Ocelot.Cache
                 _cacheManager.Remove(key);
             }
 
-            _cacheManager.Add(new CacheItem<T>(key, value, ExpirationMode.Absolute, ttl));
+            Add(key, value, ttl, region);
         }
 
         public T Get(string key)
         {
             return _cacheManager.Get<T>(key);
         }
+
+        public void ClearRegion(string region)
+        {
+            _cacheManager.ClearRegion(region);
+        }
     }
 }

src/Ocelot/Configuration/Repository/ConsulOcelotConfigurationRepository.cs

@@ -68,7 +68,7 @@ namespace Ocelot.Configuration.Repository
 
             if (result.Response)
             {
-                _cache.AddAndDelete(_ocelotConfiguration, ocelotConfiguration, TimeSpan.FromSeconds(3));
+                _cache.AddAndDelete(_ocelotConfiguration, ocelotConfiguration, TimeSpan.FromSeconds(3), "OcelotConfiguration");
 
                 return new OkResponse();
             }

src/Ocelot/Controllers/OutputCacheController.cs

@@ -0,0 +1,33 @@
+using System.Net.Http;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Ocelot.Cache;
+
+namespace Ocelot.Controllers
+{
+    [Authorize]
+    [Route("cache")]
+    public class OutputCacheController : Controller
+    {
+        private IOcelotCache<HttpResponseMessage> _cache;
+
+        public OutputCacheController(IOcelotCache<HttpResponseMessage> cache)
+        {
+            _cache = cache;
+        }
+
+        [HttpGet]
+        public IActionResult Get()
+        {
+            return new NotFoundResult();
+        }
+
+        [HttpDelete]
+        [Route("{region}")]
+        public IActionResult Delete(string region)
+        {
+            _cache.ClearRegion(region);
+            return new NoContentResult();
+        }
+    }
+}

test/Ocelot.UnitTests/Cache/CacheManagerCacheTests.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using CacheManager.Core;
 using Moq;
 using Ocelot.Cache;
@@ -16,12 +17,14 @@ namespace Ocelot.UnitTests.Cache
         private string _value;
         private string _resultGet;
         private TimeSpan _ttlSeconds;
+        private List<string> _resultKeys;
 
         public CacheManagerCacheTests()
         {
             _mockCacheManager = new Mock<ICacheManager<string>>();
             _ocelotOcelotCacheManager = new OcelotCacheManagerCache<string>(_mockCacheManager.Object);
         }
+
         [Fact]
         public void should_get_from_cache()
         {
@@ -29,7 +32,6 @@ namespace Ocelot.UnitTests.Cache
                 .When(x => x.WhenIGetFromTheCache())
                 .Then(x => x.ThenTheResultIs("someValue"))
                 .BDDfy();
-
         }
 
         [Fact]
@@ -40,13 +42,37 @@ namespace Ocelot.UnitTests.Cache
                 .BDDfy();
         }
 
+        [Fact]
+        public void should_delete_key_from_cache()
+        {
+            this.Given(_ => GivenTheFollowingRegion("fookey"))
+                .When(_ => WhenIDeleteTheRegion("fookey"))
+                .Then(_ => ThenTheRegionIsDeleted("fookey"))
+                .BDDfy();
+        }
+
+        private void WhenIDeleteTheRegion(string region)
+        {
+            _ocelotOcelotCacheManager.ClearRegion(region);
+        }
+
+        private void ThenTheRegionIsDeleted(string region)
+        {
+            _mockCacheManager
+                .Verify(x => x.ClearRegion(region), Times.Once);
+        }
+
+        private void GivenTheFollowingRegion(string key)
+        {
+            _ocelotOcelotCacheManager.Add(key, "doesnt matter", TimeSpan.FromSeconds(10), "region");
+        }
+
         private void WhenIAddToTheCache(string key, string value, TimeSpan ttlSeconds)
         {
             _key = key;
             _value = value;
             _ttlSeconds = ttlSeconds;
-
-            _ocelotOcelotCacheManager.Add(_key, _value, _ttlSeconds);
+            _ocelotOcelotCacheManager.Add(_key, _value, _ttlSeconds, "region");
         }
 
         private void ThenTheCacheIsCalledCorrectly()

test/Ocelot.UnitTests/Cache/OutputCacheMiddlewareTests.cs

@@ -124,7 +124,7 @@ namespace Ocelot.UnitTests.Cache
         private void ThenTheCacheAddIsCalledCorrectly()
         {
             _cacheManager
-                .Verify(x => x.Add(It.IsAny<string>(), It.IsAny<HttpResponseMessage>(), It.IsAny<TimeSpan>()), Times.Once);
+                .Verify(x => x.Add(It.IsAny<string>(), It.IsAny<HttpResponseMessage>(), It.IsAny<TimeSpan>(), It.IsAny<string>()), Times.Once);
         }
 
         private void GivenResponseIsNotCached()

test/Ocelot.UnitTests/Controllers/OutputCacheControllerTests.cs

@@ -0,0 +1,70 @@
+using Xunit;
+using Shouldly;
+using TestStack.BDDfy;
+using Ocelot.Controllers;
+using System;
+using Moq;
+using Ocelot.Cache;
+using System.Net.Http;
+using System.Collections.Generic;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Ocelot.UnitTests.Controllers
+{
+    public class OutputCacheControllerTests
+    {
+        private OutputCacheController _controller;
+        private Mock<IOcelotCache<HttpResponseMessage>> _cache;
+        private IActionResult _result;
+
+        public OutputCacheControllerTests()
+        {
+            _cache = new Mock<IOcelotCache<HttpResponseMessage>>();
+            _controller = new OutputCacheController(_cache.Object);
+        }
+
+        [Fact]
+        public void should_get_all_keys_from_server()
+        {
+            this.Given(_ => GivenTheFollowingKeys(new List<string>{"b", "a"}))
+                .When(_ => WhenIGetTheKeys())
+                .Then(_ => ThenTheKeysAreReturned())
+                .BDDfy();
+        }
+
+        [Fact]
+        public void should_delete_key()
+        {
+             this.When(_ => WhenIDeleteTheKey("a"))
+                .Then(_ => ThenTheKeyIsDeleted("a"))
+                .BDDfy();
+        }
+
+        private void ThenTheKeyIsDeleted(string key)
+        {
+            _result.ShouldBeOfType<NoContentResult>();
+            _cache
+                .Verify(x => x.ClearRegion(key), Times.Once);
+        }
+
+        private void WhenIDeleteTheKey(string key)
+        {
+            _result = _controller.Delete(key);
+        }
+
+        private void GivenTheFollowingKeys(List<string> keys)
+        {
+            
+        }
+
+        private void WhenIGetTheKeys()
+        {
+            _result = _controller.Get();
+        }
+
+        private void ThenTheKeysAreReturned()
+        {
+            _result.ShouldBeOfType<OkObjectResult>();
+        }
+    }
+}