Allow multiple topics to call the same endpoint (#763)

* Allow multiple topics to call the same endpoint Using the WithTopic builder pattern allows you to specify multiple topics that route to a single endpoint. Given the topics are unique, this should be a valid case. This change allows for a single endpoint to bind to multiple topics. Note that this can only be done via the EndpointBuilder and not the TopicAttribute. #715 * Let TopicAttribute to be specified multiple times The endpoint builder allowed for multiple WithTopic calls so the attribute should match that behavior.
dapr · Oct 26, 2021 · cc1b097 · cc1b097
1 parent f325863
commit cc1b097
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Showing 5 changed files with 43 additions and 12 deletions.
diff --git a/src/Dapr.AspNetCore/DaprEndpointRouteBuilderExtensions.cs b/src/Dapr.AspNetCore/DaprEndpointRouteBuilderExtensions.cs
@@ -58,15 +58,25 @@ private static IEndpointConventionBuilder CreateSubscribeEndPoint(IEndpointRoute
                 var dataSource = context.RequestServices.GetRequiredService<EndpointDataSource>();
                 var subscriptions = dataSource.Endpoints
                     .OfType<RouteEndpoint>()
-                    .Where(e => e.Metadata.GetMetadata<ITopicMetadata>()?.Name != null) // only endpoints which have TopicAttribute with not null Name.
+                    .Where(e => e.Metadata.GetOrderedMetadata<ITopicMetadata>().Any(t => t.Name != null)) // only endpoints which have TopicAttribute with not null Name.
+                    .SelectMany(e =>
+                    {
+                        var topicMetadata = e.Metadata.GetOrderedMetadata<ITopicMetadata>();
+                        var subs = new List<(string PubsubName, string Name, bool? EnableRawPayload, string Match, int Priority, RoutePattern RoutePattern)>();
+
+                        for (int i = 0; i < topicMetadata.Count(); i++)
+                        {
+                            subs.Add((topicMetadata[i].PubsubName,
+                                topicMetadata[i].Name,
+                                (topicMetadata[i] as IRawTopicMetadata)?.EnableRawPayload,
+                                topicMetadata[i].Match,
+                                topicMetadata[i].Priority,
+                                e.RoutePattern));
+                        }
+
+                        return subs;
+                    })
                     .Distinct()
-                    .Select(e => (
-                        e.Metadata.GetMetadata<ITopicMetadata>().PubsubName,
-                        e.Metadata.GetMetadata<ITopicMetadata>().Name,
-                        e.Metadata.GetMetadata<IRawTopicMetadata>()?.EnableRawPayload,
-                        e.Metadata.GetMetadata<ITopicMetadata>().Match,
-                        e.Metadata.GetMetadata<ITopicMetadata>().Priority,
-                        e.RoutePattern))
                     .GroupBy(e => new { e.PubsubName, e.Name })
                     .Select(e => e.OrderBy(e => e.Priority))
                     .Select(e =>
@@ -79,7 +89,7 @@ private static IEndpointConventionBuilder CreateSubscribeEndPoint(IEndpointRoute
 
                         if (logger != null)
                         {
-                            if (defaultRoutes.Count() > 1)
+                            if (defaultRoutes.Count > 1)
                             {
                                 logger.LogError("A default subscription to topic {name} on pubsub {pubsub} already exists.", first.Name, first.PubsubName);
                             }
@@ -105,7 +115,7 @@ private static IEndpointConventionBuilder CreateSubscribeEndPoint(IEndpointRoute
                         };
 
                         // Use the V2 routing rules structure
-                        if (rules.Count() > 0)
+                        if (rules.Count > 0)
                         {
                             subscription.Routes = new Routes
                             {

diff --git a/src/Dapr.AspNetCore/TopicAttribute.cs b/src/Dapr.AspNetCore/TopicAttribute.cs
@@ -10,6 +10,7 @@ namespace Dapr
     /// <summary>
     /// TopicAttribute describes an endpoint as a subscriber to a topic.
     /// </summary>
+    [AttributeUsage(AttributeTargets.All, AllowMultiple = true)]
     public class TopicAttribute : Attribute, ITopicMetadata, IRawTopicMetadata
     {
         /// <summary>

diff --git a/test/Dapr.AspNetCore.IntegrationTest.App/DaprController.cs b/test/Dapr.AspNetCore.IntegrationTest.App/DaprController.cs
@@ -53,6 +53,19 @@ public void TopicEImportant()
         {
         }
 
+        [Topic("pubsub", "F")]
+        [Topic("pubsub", "F.1", true)]
+        [HttpPost("/multiTopicAttr")]
+        public void MultipleTopics()
+        {
+        }
+
+        [Topic("pubsub", "splitTopicAttr", true)]
+        [HttpPost("/splitTopics")]
+        public void SplitTopic()
+        {
+        }
+
         [Topic("pubsub", "register-user")]
         [HttpPost("/register-user")]
         public ActionResult<UserInfo> RegisterUser(UserInfo user)

diff --git a/test/Dapr.AspNetCore.IntegrationTest.App/Startup.cs b/test/Dapr.AspNetCore.IntegrationTest.App/Startup.cs
@@ -53,7 +53,9 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                 endpoints.MapSubscribeHandler();
                 endpoints.MapControllers();
 
-                endpoints.MapPost("/topic-a", context => Task.CompletedTask).WithTopic("testpubsub", "A");
+                endpoints.MapPost("/topic-a", context => Task.CompletedTask).WithTopic("testpubsub", "A").WithTopic("testpubsub", "A.1");
+
+                endpoints.MapPost("/splitTopics", context => Task.CompletedTask).WithTopic("pubsub", "splitTopicBuilder");
 
                 endpoints.MapPost("/routingwithstateentry/{widget}", async context =>
                 {

diff --git a/test/Dapr.AspNetCore.IntegrationTest/SubscribeEndpointTest.cs b/test/Dapr.AspNetCore.IntegrationTest/SubscribeEndpointTest.cs
@@ -31,7 +31,7 @@ public async Task SubscribeEndpoint_ReportsTopics()
                     var json = await JsonSerializer.DeserializeAsync<JsonElement>(stream);
 
                     json.ValueKind.Should().Be(JsonValueKind.Array);
-                    json.GetArrayLength().Should().Be(7);
+                    json.GetArrayLength().Should().Be(12);
                     var subscriptions = new List<(string PubsubName, string Topic, string Route, string rawPayload, string match)>();
                     foreach (var element in json.EnumerateArray())
                     {
@@ -66,6 +66,7 @@ public async Task SubscribeEndpoint_ReportsTopics()
                     }
 
                     subscriptions.Should().Contain(("testpubsub", "A", "topic-a", string.Empty, string.Empty));
+                    subscriptions.Should().Contain(("testpubsub", "A.1", "topic-a", string.Empty, string.Empty));
                     subscriptions.Should().Contain(("pubsub", "B", "B", string.Empty, string.Empty));
                     subscriptions.Should().Contain(("custom-pubsub", "custom-C", "C", string.Empty, string.Empty));
                     subscriptions.Should().Contain(("pubsub", "register-user", "register-user", string.Empty, string.Empty));
@@ -74,6 +75,10 @@ public async Task SubscribeEndpoint_ReportsTopics()
                     subscriptions.Should().Contain(("pubsub", "E", "E", string.Empty, string.Empty));
                     subscriptions.Should().Contain(("pubsub", "E", "E-Critical", string.Empty, "event.type == \"critical\""));
                     subscriptions.Should().Contain(("pubsub", "E", "E-Important", string.Empty, "event.type == \"important\""));
+                    subscriptions.Should().Contain(("pubsub", "F", "multiTopicAttr", string.Empty, string.Empty));
+                    subscriptions.Should().Contain(("pubsub", "F.1", "multiTopicAttr", "true", string.Empty));
+                    subscriptions.Should().Contain(("pubsub", "splitTopicBuilder", "splitTopics", string.Empty, string.Empty));
+                    subscriptions.Should().Contain(("pubsub", "splitTopicAttr", "splitTopics", "true", string.Empty));
 
                     // Test priority route sorting
                     var eTopic = subscriptions.FindAll(e => e.Topic == "E");