Enable container-to-container service communication

src/Aspire.Hosting.Azure.EventHubs/AzureEventHubsExtensions.cs

@@ -169,8 +169,8 @@ public static IResourceBuilder<AzureEventHubsResource> RunAsEmulator(this IResou
             var tableEndpoint = storage.GetEndpoint("table");
 
             context.EnvironmentVariables.Add("ACCEPT_EULA", "Y");
-            context.EnvironmentVariables.Add("BLOB_SERVER", $"{blobEndpoint.ContainerHost}:{blobEndpoint.Port}");
-            context.EnvironmentVariables.Add("METADATA_SERVER", $"{tableEndpoint.ContainerHost}:{tableEndpoint.Port}");
+            context.EnvironmentVariables.Add("BLOB_SERVER", $"{blobEndpoint.Resource.Name}:{blobEndpoint.TargetPort}");
+            context.EnvironmentVariables.Add("METADATA_SERVER", $"{tableEndpoint.Resource.Name}:{tableEndpoint.TargetPort}");
         }));
 
         if (configureContainer != null)

src/Aspire.Hosting.Kafka/KafkaBuilderExtensions.cs

@@ -92,7 +92,9 @@ public static IResourceBuilder<KafkaServerResource> WithKafkaUI(this IResourceBu
         static void ConfigureKafkaUIContainer(EnvironmentCallbackContext context, EndpointReference endpoint, int index)
         {
             var bootstrapServers = context.ExecutionContext.IsRunMode
-                ? ReferenceExpression.Create($"{endpoint.ContainerHost}:{endpoint.Property(EndpointProperty.Port)}")
+                // In run mode, Kafka UI assumes Kafka is being accessed over a default Aspire container network and hardcodes the host as the Kafka resource name
+                // This will need to be refactored once updated service discovery APIs are available
+                ? ReferenceExpression.Create($"{endpoint.Resource.Name}:{endpoint.Property(EndpointProperty.TargetPort)}")
                 : ReferenceExpression.Create($"{endpoint.Property(EndpointProperty.Host)}:{endpoint.Property(EndpointProperty.Port)}");
 
             context.EnvironmentVariables.Add($"KAFKA_CLUSTERS_{index}_NAME", endpoint.Resource.Name);
@@ -164,7 +166,9 @@ private static void ConfigureKafkaContainer(EnvironmentCallbackContext context,
         var internalEndpoint = resource.InternalEndpoint;
 
         var advertisedListeners = context.ExecutionContext.IsRunMode
-            ? ReferenceExpression.Create($"PLAINTEXT://localhost:29092,PLAINTEXT_HOST://localhost:{primaryEndpoint.Property(EndpointProperty.Port)},PLAINTEXT_INTERNAL://{internalEndpoint.ContainerHost}:{internalEndpoint.Property(EndpointProperty.Port)}")
+            // In run mode, PLAINTEXT_INTERNAL assumes kafka is being accessed over a default Aspire container network and hardcodes the resource address
+            // This will need to be refactored once updated service discovery APIs are available
+            ? ReferenceExpression.Create($"PLAINTEXT://localhost:29092,PLAINTEXT_HOST://localhost:{primaryEndpoint.Property(EndpointProperty.Port)},PLAINTEXT_INTERNAL://{resource.Name}:{internalEndpoint.Property(EndpointProperty.TargetPort)}")
             : ReferenceExpression.Create(
             $"PLAINTEXT://{primaryEndpoint.Property(EndpointProperty.Host)}:29092,PLAINTEXT_HOST://{primaryEndpoint.Property(EndpointProperty.Host)}:{primaryEndpoint.Property(EndpointProperty.Port)},PLAINTEXT_INTERNAL://{internalEndpoint.Property(EndpointProperty.Host)}:{internalEndpoint.Property(EndpointProperty.Port)}");
 

src/Aspire.Hosting.Milvus/MilvusBuilderExtensions.cs

@@ -25,8 +25,8 @@ public static class MilvusBuilderExtensions
     /// var milvus = builder.AddMilvus("milvus");
     /// var api = builder.AddProject<Projects.Api>("api")
     ///   .WithReference(milvus);
-    ///  
-    /// builder.Build().Run(); 
+    ///
+    /// builder.Build().Run();
     /// </code>
     /// </example>
     /// <remarks>
@@ -80,11 +80,11 @@ public static IResourceBuilder<MilvusServerResource> AddMilvus(this IDistributed
     ///
     /// var booksdb = builder.AddMilvus("milvus");
     ///   .AddDatabase("booksdb");
-    /// 
+    ///
     /// var api = builder.AddProject&lt;Projects.Api&gt;("api")
     ///   .WithReference(booksdb);
-    ///  
-    /// builder.Build().Run(); 
+    ///
+    /// builder.Build().Run();
     /// </code>
     /// </example>
     /// <param name="builder">The Milvus server resource builder.</param>
@@ -117,8 +117,8 @@ public static IResourceBuilder<MilvusDatabaseResource> AddDatabase(this IResourc
     ///   .WithAttu();
     /// var api = builder.AddProject&lt;Projects.Api&gt;("api")
     ///   .WithReference(milvus);
-    ///  
-    /// builder.Build().Run(); 
+    ///
+    /// builder.Build().Run();
     /// </code>
     /// </example>
     /// <param name="builder">The Milvus server resource builder.</param>
@@ -186,6 +186,8 @@ public static IResourceBuilder<MilvusServerResource> WithConfigurationBindMount(
 
     private static void ConfigureAttuContainer(EnvironmentCallbackContext context, MilvusServerResource resource)
     {
-        context.EnvironmentVariables.Add("MILVUS_URL", $"{resource.PrimaryEndpoint.Scheme}://{resource.PrimaryEndpoint.ContainerHost}:{resource.PrimaryEndpoint.Port}");
+        // Attu assumes Milvus is being accessed over a default Aspire container network and hardcodes the resource address
+        // This will need to be refactored once updated service discovery APIs are available
+        context.EnvironmentVariables.Add("MILVUS_URL", $"{resource.PrimaryEndpoint.Scheme}://{resource.Name}:{resource.PrimaryEndpoint.TargetPort}");
     }
 }

src/Aspire.Hosting.MongoDB/MongoDBBuilderExtensions.cs

@@ -146,7 +146,9 @@ public static IResourceBuilder<MongoDBServerResource> WithInitBindMount(this IRe
 
     private static void ConfigureMongoExpressContainer(EnvironmentCallbackContext context, MongoDBServerResource resource)
     {
-        context.EnvironmentVariables.Add("ME_CONFIG_MONGODB_URL", $"mongodb://{resource.PrimaryEndpoint.ContainerHost}:{resource.PrimaryEndpoint.Port}/?directConnection=true");
+        // Mongo Exporess assumes Mongo is being accessed over a default Aspire container network and hardcodes the resource address
+        // This will need to be refactored once updated service discovery APIs are available
+        context.EnvironmentVariables.Add("ME_CONFIG_MONGODB_URL", $"mongodb://{resource.Name}:{resource.PrimaryEndpoint.TargetPort}/?directConnection=true");
         context.EnvironmentVariables.Add("ME_CONFIG_BASICAUTH", "false");
     }
 }

src/Aspire.Hosting.MySql/MySqlBuilderExtensions.cs

@@ -106,7 +106,9 @@ public static IResourceBuilder<T> WithPhpMyAdmin<T>(this IResourceBuilder<T> bui
                     var endpoint = singleInstance.PrimaryEndpoint;
                     phpMyAdminContainerBuilder.WithEnvironment(context =>
                     {
-                        context.EnvironmentVariables.Add("PMA_HOST", $"{endpoint.ContainerHost}:{endpoint.Port}");
+                        // PhpMyAdmin assumes MySql is being accessed over a default Aspire container network and hardcodes the resource address
+                        // This will need to be refactored once updated service discovery APIs are available
+                        context.EnvironmentVariables.Add("PMA_HOST", $"{endpoint.Resource.Name}:{endpoint.TargetPort}");
                         context.EnvironmentVariables.Add("PMA_USER", "root");
                         context.EnvironmentVariables.Add("PMA_PASSWORD", singleInstance.PasswordParameter.Value);
                     });
@@ -127,7 +129,9 @@ public static IResourceBuilder<T> WithPhpMyAdmin<T>(this IResourceBuilder<T> bui
                     {
                         var endpoint = mySqlInstance.PrimaryEndpoint;
                         writer.WriteLine("$i++;");
-                        writer.WriteLine($"$cfg['Servers'][$i]['host'] = '{endpoint.ContainerHost}:{endpoint.Port}';");
+                        // PhpMyAdmin assumes MySql is being accessed over a default Aspire container network and hardcodes the resource address
+                        // This will need to be refactored once updated service discovery APIs are available
+                        writer.WriteLine($"$cfg['Servers'][$i]['host'] = '{endpoint.Resource.Name}:{endpoint.TargetPort}';");
                         writer.WriteLine($"$cfg['Servers'][$i]['verbose'] = '{mySqlInstance.Name}';");
                         writer.WriteLine($"$cfg['Servers'][$i]['auth_type'] = 'cookie';");
                         writer.WriteLine($"$cfg['Servers'][$i]['user'] = 'root';");
@@ -157,7 +161,7 @@ public static IResourceBuilder<T> WithPhpMyAdmin<T>(this IResourceBuilder<T> bui
     public static IResourceBuilder<PhpMyAdminContainerResource> WithHostPort(this IResourceBuilder<PhpMyAdminContainerResource> builder, int? port)
     {
         ArgumentNullException.ThrowIfNull(builder);
-        
+
         return builder.WithEndpoint("http", endpoint =>
         {
             endpoint.Port = port;

src/Aspire.Hosting.PostgreSQL/PostgresBuilderExtensions.cs

@@ -201,8 +201,10 @@ public static IResourceBuilder<T> WithPgAdmin<T>(this IResourceBuilder<T> builde
                         writer.WriteStartObject($"{serverIndex}");
                         writer.WriteString("Name", postgresInstance.Name);
                         writer.WriteString("Group", "Servers");
-                        writer.WriteString("Host", endpoint.ContainerHost);
-                        writer.WriteNumber("Port", endpoint.Port);
+                        // PgAdmin assumes Postgres is being accessed over a default Aspire container network and hardcodes the resource address
+                        // This will need to be refactored once updated service discovery APIs are available
+                        writer.WriteString("Host", endpoint.Resource.Name);
+                        writer.WriteNumber("Port", (int)endpoint.TargetPort!);
                         writer.WriteString("Username", "postgres");
                         writer.WriteString("SSLMode", "prefer");
                         writer.WriteString("MaintenanceDB", "postgres");
@@ -269,11 +271,11 @@ public static IResourceBuilder<PgWebContainerResource> WithHostPort(this IResour
     /// var postgres = builder.AddPostgres("postgres")
     ///    .WithPgWeb();
     /// var db = postgres.AddDatabase("db");
-    ///   
+    ///
     /// var api = builder.AddProject&lt;Projects.Api&gt;("api")
     ///   .WithReference(db);
-    ///  
-    /// builder.Build().Run(); 
+    ///
+    /// builder.Build().Run();
     /// </code>
     /// </example>
     /// <remarks>
@@ -320,9 +322,11 @@ public static IResourceBuilder<PostgresServerResource> WithPgWeb(this IResourceB
                 {
                     var user = postgresDatabase.Parent.UserNameParameter?.Value ?? "postgres";
 
+                    // PgAdmin assumes Postgres is being accessed over a default Aspire container network and hardcodes the resource address
+                    // This will need to be refactored once updated service discovery APIs are available
                     var fileContent = $"""
-                        host = "{postgresDatabase.Parent.PrimaryEndpoint.ContainerHost}"
-                        port = {postgresDatabase.Parent.PrimaryEndpoint.Port}
+                        host = "{postgresDatabase.Parent.Name}"
+                        port = {postgresDatabase.Parent.PrimaryEndpoint.TargetPort}
                         user = "{user}"
                         password = "{postgresDatabase.Parent.PasswordParameter.Value}"
                         database = "{postgresDatabase.DatabaseName}"

src/Aspire.Hosting.Redis/RedisBuilderExtensions.cs

@@ -100,7 +100,9 @@ public static IResourceBuilder<RedisResource> WithRedisCommander(this IResourceB
                 {
                     if (redisInstance.PrimaryEndpoint.IsAllocated)
                     {
-                        var hostString = $"{(hostsVariableBuilder.Length > 0 ? "," : string.Empty)}{redisInstance.Name}:{redisInstance.PrimaryEndpoint.ContainerHost}:{redisInstance.PrimaryEndpoint.Port}:0";
+                        // Redis Commander assumes Redis is being accessed over a default Aspire container network and hardcodes the resource address
+                        // This will need to be refactored once updated service discovery APIs are available
+                        var hostString = $"{(hostsVariableBuilder.Length > 0 ? "," : string.Empty)}{redisInstance.Name}:{redisInstance.Name}:{redisInstance.PrimaryEndpoint.TargetPort}:0";
                         hostsVariableBuilder.Append(hostString);
                     }
                 }

src/Aspire.Hosting/ApplicationModel/EndpointReference.cs

@@ -226,5 +226,5 @@ public enum EndpointProperty
     /// <summary>
     /// The target port of the endpoint.
     /// </summary>
-    TargetPort
+    TargetPort,
 }

src/Aspire.Hosting/Dcp/ApplicationExecutor.cs

@@ -132,6 +132,8 @@ public async Task RunApplicationAsync(CancellationToken cancellationToken = defa
 
             await CreateServicesAsync(cancellationToken).ConfigureAwait(false);
 
+            await CreateContainerNetworksAsync(cancellationToken).ConfigureAwait(false);
+
             await CreateContainersAndExecutablesAsync(cancellationToken).ConfigureAwait(false);
 
             var afterResourcesCreatedEvent = new AfterResourcesCreatedEvent(serviceProvider, _model);
@@ -901,6 +903,18 @@ await execution.ExecuteAsync(async (attemptCancellationToken) =>
         }
     }
 
+    private async Task CreateContainerNetworksAsync(CancellationToken cancellationToken)
+    {
+        var toCreate = _appResources.Where(r => r.DcpResource is ContainerNetwork);
+        foreach (var containerNetwork in toCreate)
+        {
+            if (containerNetwork.DcpResource is ContainerNetwork cn)
+            {
+                await kubernetesService.CreateAsync(cn, cancellationToken).ConfigureAwait(false);
+            }
+        }
+    }
+
     private async Task CreateContainersAndExecutablesAsync(CancellationToken cancellationToken)
     {
         var toCreate = _appResources.Where(r => r.DcpResource is Container || r.DcpResource is Executable || r.DcpResource is ExecutableReplicaSet);
@@ -1394,6 +1408,15 @@ private void PrepareContainers()
                 }
             }
 
+            ctr.Spec.Networks = new List<ContainerNetworkConnection>
+            {
+                new ContainerNetworkConnection
+                {
+                    Name = "aspire-network",
+                    Aliases = new List<string> { container.Name },
+                }
+            };
+
             var containerAppResource = new AppResource(container, ctr);
             AddServicesProducedInfo(container, ctr, containerAppResource);
             _appResources.Add(containerAppResource);
@@ -1444,6 +1467,14 @@ await notificationService.PublishUpdateAsync(cr.ModelResource, s => s with
             }
 
             var tasks = new List<Task>();
+
+            // Create a custom container network for Aspire if there are container resources
+            if (containerResources.Any())
+            {
+                // The network will be created with a unique postfix to avoid conflicts with other Aspire AppHost networks
+                tasks.Add(kubernetesService.CreateAsync(ContainerNetwork.Create("aspire-network"), cancellationToken));
+            }
+
             foreach (var cr in containerResources)
             {
                 tasks.Add(CreateContainerAsyncCore(cr, cancellationToken));

src/Aspire.Hosting/Dcp/Model/GroupVersion.cs

@@ -33,6 +33,7 @@ static Dcp()
     {
         Schema.Add<Executable>(ExecutableKind, "executables");
         Schema.Add<Container>(ContainerKind, "containers");
+        Schema.Add<ContainerNetwork>(ContainerNetworkKind, "containernetworks");
         Schema.Add<Service>(ServiceKind, "services");
         Schema.Add<Endpoint>(EndpointKind, "endpoints");
         Schema.Add<ExecutableReplicaSet>(ExecutableReplicaSetKind, "executablereplicasets");

src/Aspire.Hosting/Dcp/Model/Network.cs

@@ -84,7 +84,7 @@ public ContainerNetwork(ContainerNetworkSpec spec) : base(spec) { }
 
     public static ContainerNetwork Create(string name, bool useIpV6 = false)
     {
-        var c = new ContainerNetwork(new ContainerNetworkSpec { NetworkName = name, IPV6 = useIpV6 });
+        var c = new ContainerNetwork(new ContainerNetworkSpec { IPV6 = useIpV6 });
 
         c.Kind = Dcp.ContainerNetworkKind;
         c.ApiVersion = Dcp.GroupVersion.ToString();

tests/Aspire.Hosting.MongoDB.Tests/AddMongoDBTests.cs

@@ -136,14 +136,12 @@ public void WithMongoExpressSupportsChangingHostPort()
         Assert.Equal(1000, endpoint.Port);
     }
 
-    [Theory]
-    [InlineData("host.docker.internal")]
-    [InlineData("host.containers.internal")]
-    public async Task WithMongoExpressUsesContainerHost(string containerHost)
+    [Fact]
+    public async Task WithMongoExpressUsesContainerHost()
     {
         using var builder = TestDistributedApplicationBuilder.Create();
         builder.AddMongoDB("mongo")
-            .WithEndpoint("tcp", e => e.AllocatedEndpoint = new AllocatedEndpoint(e, "localhost", 3000, containerHost))
+            .WithEndpoint("tcp", e => e.AllocatedEndpoint = new AllocatedEndpoint(e, "localhost", 3000))
             .WithMongoExpress();
 
         var mongoExpress = Assert.Single(builder.Resources.OfType<MongoExpressContainerResource>());
@@ -154,7 +152,7 @@ public async Task WithMongoExpressUsesContainerHost(string containerHost)
             e =>
             {
                 Assert.Equal("ME_CONFIG_MONGODB_URL", e.Key);
-                Assert.Equal($"mongodb://{containerHost}:3000/?directConnection=true", e.Value);
+                Assert.Equal($"mongodb://mongo:3000/?directConnection=true", e.Value);
             },
             e =>
             {

tests/Aspire.Hosting.MySql.Tests/AddMySqlTests.cs

@@ -231,8 +231,7 @@ public void WithMySqlTwiceEndsUpWithOneAdminContainer()
     }
 
     [Theory]
-    [InlineData("host.docker.internal")]
-    [InlineData("host.containers.internal")]
+    [InlineData("mySql")]
     public async Task SingleMySqlInstanceProducesCorrectMySqlHostsVariable(string containerHost)
     {
         var builder = DistributedApplication.CreateBuilder();
@@ -266,17 +265,15 @@ public void WithPhpMyAdminAddsContainer()
         Assert.Equal("/etc/phpmyadmin/config.user.inc.php", volume.Target);
     }
 
-    [Theory]
-    [InlineData("host.docker.internal")]
-    [InlineData("host.containers.internal")]
-    public void WithPhpMyAdminProducesValidServerConfigFile(string containerHost)
+    [Fact]
+    public void WithPhpMyAdminProducesValidServerConfigFile()
     {
         var builder = DistributedApplication.CreateBuilder();
         var mysql1 = builder.AddMySql("mysql1").WithPhpMyAdmin(c => c.WithHostPort(8081));
         var mysql2 = builder.AddMySql("mysql2").WithPhpMyAdmin(c => c.WithHostPort(8081));
 
         // Add fake allocated endpoints.
-        mysql1.WithEndpoint("tcp", e => e.AllocatedEndpoint = new AllocatedEndpoint(e, "localhost", 5001, containerHost));
+        mysql1.WithEndpoint("tcp", e => e.AllocatedEndpoint = new AllocatedEndpoint(e, "localhost", 5001));
         mysql2.WithEndpoint("tcp", e => e.AllocatedEndpoint = new AllocatedEndpoint(e, "localhost", 5002, "host3"));
 
         var myAdmin = builder.Resources.Single(r => r.Name.EndsWith("-phpmyadmin"));
@@ -291,7 +288,7 @@ public void WithPhpMyAdminProducesValidServerConfigFile(string containerHost)
         var fileContents = new StreamReader(stream).ReadToEnd();
 
         // check to see that the two hosts are in the file
-        string pattern1 = $@"\$cfg\['Servers'\]\[\$i\]\['host'\] = '{containerHost}:5001';";
+        string pattern1 = $@"\$cfg\['Servers'\]\[\$i\]\['host'\] = 'mysql1:5001';";
         string pattern2 = @"\$cfg\['Servers'\]\[\$i\]\['host'\] = 'host3:5002';";
         Match match1 = Regex.Match(fileContents, pattern1);
         Assert.True(match1.Success);