[ci skip] Fixed wrong port being used for management API

Fixed exchange not being created for bindings and publishing
Added documentation for DataAnnotations package

Tapeti/Config/ITapetiConfigBuilder.cs

@@ -82,8 +82,7 @@ namespace Tapeti.Config
         /// Note that access to the RabbitMQ Management plugin's REST API is required for this
         /// feature to work, since AMQP does not provide a way to query existing bindings.
         /// </remarks>
-        ITapetiConfigBuilder EnableDeclareDurableQueues();
-
+        ITapetiConfigBuilder EnableDeclareDurableQueues();        
 
         /// <summary>
         /// Configures the automatic creation of durable queues and updating of their bindings.

Tapeti/Connection/TapetiClient.cs

@@ -111,6 +111,8 @@ namespace Tapeti.Connection
 
                 WithRetryableChannel(channel =>
                 {
+                    DeclareExchange(channel, exchange);
+
                     // The delivery tag is lost after a reconnect, register under the new tag
                     if (config.Features.PublisherConfirms)
                     {
@@ -230,18 +232,20 @@ namespace Tapeti.Connection
         {
             await taskQueue.Value.Add(async () =>
             {
-                var existingBindings = await GetQueueBindings(queueName);
+                var existingBindings = (await GetQueueBindings(queueName)).ToList();
+                var currentBindings = bindings.ToList();
 
                 WithRetryableChannel(channel =>
                 {
                     channel.QueueDeclare(queueName, true, false, false);
 
-                    var currentBindings = bindings.ToList();
-
-                    foreach (var binding in currentBindings)
+                    foreach (var binding in currentBindings.Except(existingBindings))
+                    {
+                        DeclareExchange(channel, binding.Exchange);
                         channel.QueueBind(queueName, binding.Exchange, binding.RoutingKey);
+                    }
 
-                    foreach (var deletedBinding in existingBindings.Where(binding => !currentBindings.Any(b => b.Exchange == binding.Exchange && b.RoutingKey == binding.RoutingKey)))
+                    foreach (var deletedBinding in existingBindings.Except(currentBindings))
                         channel.QueueUnbind(queueName, deletedBinding.Exchange, deletedBinding.RoutingKey);
                 });
             });
@@ -288,6 +292,7 @@ namespace Tapeti.Connection
             {
                 WithRetryableChannel(channel =>
                 {
+                    DeclareExchange(channel, binding.Exchange); 
                     channel.QueueBind(queueName, binding.Exchange, binding.RoutingKey);                    
                 });
             });
@@ -372,7 +377,7 @@ namespace Tapeti.Connection
         {
             var virtualHostPath = Uri.EscapeDataString(connectionParams.VirtualHost);
             var queuePath = Uri.EscapeDataString(queueName);
-            var requestUri = new Uri($"{connectionParams.HostName}:{connectionParams.Port}/api/queues/{virtualHostPath}/{queuePath}/bindings");
+            var requestUri = new Uri($"http://{connectionParams.HostName}:{connectionParams.ManagementPort}/api/queues/{virtualHostPath}/{queuePath}/bindings");
 
             using (var request = new HttpRequestMessage(HttpMethod.Get, requestUri))
             { 
@@ -414,6 +419,21 @@ namespace Tapeti.Connection
         }
 
 
+        private readonly HashSet<string> declaredExchanges = new HashSet<string>();
+
+        private void DeclareExchange(IModel channel, string exchange)
+        {
+            if (string.IsNullOrEmpty(exchange))
+                return;
+
+            if (declaredExchanges.Contains(exchange))
+                return;
+
+            channel.ExchangeDeclare(exchange, "topic", true);
+            declaredExchanges.Add(exchange);
+        }
+
+
         /// <remarks>
         /// Only call this from a task in the taskQueue to ensure IModel is only used 
         /// by a single thread, as is recommended in the RabbitMQ .NET Client documentation.

Tapeti/TapetiAppSettingsConnectionParams.cs

@@ -18,6 +18,7 @@ namespace Tapeti
     ///   <item><description>rabbitmq:username</description></item>
     ///   <item><description>rabbitmq:password</description></item>
     ///   <item><description>rabbitmq:prefetchcount</description></item>
+    ///   <item><description>rabbitmq:managementport</description></item>
     /// </list>
     public class TapetiAppSettingsConnectionParams : TapetiConnectionParams
     {
@@ -28,6 +29,7 @@ namespace Tapeti
         private const string KeyUsername = "username";
         private const string KeyPassword = "password";
         private const string KeyPrefetchCount = "prefetchcount";
+        private const string KeyManagementPort = "managementport";
 
 
         /// <inheritdoc />
@@ -49,6 +51,7 @@ namespace Tapeti
             GetAppSetting(KeyUsername, value => Username = value);
             GetAppSetting(KeyPassword, value => Password = value);
             GetAppSetting(KeyPrefetchCount, value => PrefetchCount = ushort.Parse(value));
+            GetAppSetting(KeyManagementPort, value => ManagementPort = int.Parse(value));
         }
     }
 }

Tapeti/TapetiConnectionParams.cs

@@ -41,6 +41,11 @@ namespace Tapeti
         /// </summary>
         public ushort PrefetchCount { get; set; } = 50;
 
+        /// <summary>
+        /// The port the management plugin binds to. Only used when DeclareDurableQueues is enabled. Defaults to 15672.
+        /// </summary>
+        public int ManagementPort { get; set; } = 15672;
+
 
         /// <inheritdoc />
         public TapetiConnectionParams()

docs/dataannotations.rst

@@ -1,11 +1,51 @@
 Validating messages
 ===================
+To validate the contents of messages, Tapeti provides the Tapeti.DataAnnotations package. Once installed and enabled, it verifies each message that is published or consumed using the standard System.ComponentModel.DataAnnotations.
 
-.. error:: You've stumbled upon a piece of unfinished documentation.
-   Behind you is all prior knowledge. In front of you is nothing but emptyness. What do you do?
+To enable the validation extension, include it in your TapetiConfig:
 
-   1. Attempt to explore further
-   2. Complain to the author and demand your money back
-   3. Abandon all hope
+::
 
-   > |
+  var config = new TapetiConfig(new SimpleInjectorDependencyResolver(container))
+      .WithDataAnnotations()
+      .RegisterAllControllers()
+      .Build();
+
+
+Annotations
+-----------
+All `ValidationAttribute <https://docs.microsoft.com/en-us/dotnet/api/system.componentmodel.dataannotations.validationattribute>`_ derived annotations are supported. For example, use the Required attribute to indicate a field is required:
+
+::
+
+  public class RabbitEscapedMessage
+  {
+      [Required]
+      public string Name { get; set; }
+
+      public string LastKnownHutch { get; set; }
+  }
+
+Or the Range attribute to indicate valid ranges:
+
+::
+
+  public class RabbitBirthdayMessage
+  {
+      [Range(1, 15, ErrorMessage = "Sorry, we have no birthday cards for ages below {1} or above {2}")]
+      public int Age { get; set; }
+  }
+
+Required GUIDs
+--------------
+Using the standard validation attributes it is tricky to get a Guid to be required, as it is a struct which defaults to Guid.Empty. Using Nullable<Guid> may work, but then your business logic will look like it is supposed to be optional.
+
+For this reason, the Tapeti.DataAnnotations.Extensions package can be installed from NuGet into your messaging package. It contains the RequiredGuid attribute which specifically checks for Guid.Empty.
+
+::
+
+  public class RabbitBornMessage
+  {
+      [RequiredGuid]
+      public Guid RabbitId { get; set; }
+  }