Allow HostUrl to remap both address and port

playground/yarp/Yarp.AppHost/Program.cs

@@ -4,6 +4,7 @@
 using Aspire.Hosting.Yarp.Transforms;
 
 var builder = DistributedApplication.CreateBuilder(args);
+builder.Configuration["DcpPublisher:EnableAspireContainerTunnel"] = "true";
 
 var backendService = builder.AddProject<Projects.Yarp_Backend>("backend");
 

src/Aspire.Hosting.Testing/DistributedApplicationHostingTestingExtensions.cs

@@ -68,7 +68,25 @@ public static Uri GetEndpoint(this DistributedApplication app, string resourceNa
         ArgumentNullException.ThrowIfNull(app);
         ArgumentException.ThrowIfNullOrEmpty(resourceName);
 
-        return new(GetEndpointUriStringCore(app, resourceName, endpointName));
+        return GetEndpoint(app, resourceName, endpointName, networkIdentifier: null);
+    }
+
+    /// <summary>
+    /// Gets the endpoint for the specified resource.
+    /// </summary>
+    /// <param name="app">The application.</param>
+    /// <param name="resourceName">The resource name.</param>
+    /// <param name="endpointName">The optional endpoint name. If none are specified, the single defined endpoint is returned.</param>
+    /// <param name="networkIdentifier">The optional network identifier. If none is specified, the default network is used.</param>
+    /// <returns>A URI representation of the endpoint.</returns>
+    /// <exception cref="ArgumentException">The resource was not found, no matching endpoint was found, or multiple endpoints were found.</exception>
+    /// <exception cref="InvalidOperationException">The resource has no endpoints.</exception>
+    public static Uri GetEndpoint(this DistributedApplication app, string resourceName, string? endpointName = default, NetworkIdentifier? networkIdentifier)
+    {
+        ArgumentNullException.ThrowIfNull(app);
+        ArgumentException.ThrowIfNullOrEmpty(resourceName);
+
+        return new(GetEndpointUriStringCore(app, resourceName, endpointName, networkIdentifier));
     }
 
     static IResource GetResource(DistributedApplication app, string resourceName)
@@ -87,7 +105,7 @@ static IResource GetResource(DistributedApplication app, string resourceName)
         return resource;
     }
 
-    static string GetEndpointUriStringCore(DistributedApplication app, string resourceName, string? endpointName = default)
+    static string GetEndpointUriStringCore(DistributedApplication app, string resourceName, string? endpointName = default, NetworkIdentifier? networkIdentifier = default)
     {
         var resource = GetResource(app, resourceName);
         if (resource is not IResourceWithEndpoints resourceWithEndpoints)
@@ -98,11 +116,11 @@ static string GetEndpointUriStringCore(DistributedApplication app, string resour
         EndpointReference? endpoint;
         if (!string.IsNullOrEmpty(endpointName))
         {
-            endpoint = GetEndpointOrDefault(resourceWithEndpoints, endpointName);
+            endpoint = GetEndpointOrDefault(resourceWithEndpoints, endpointName, networkIdentifier);
         }
         else
         {
-            endpoint = GetEndpointOrDefault(resourceWithEndpoints, "http") ?? GetEndpointOrDefault(resourceWithEndpoints, "https");
+            endpoint = GetEndpointOrDefault(resourceWithEndpoints, "http", networkIdentifier) ?? GetEndpointOrDefault(resourceWithEndpoints, "https", networkIdentifier);
         }
 
         if (endpoint is null)
@@ -122,9 +140,9 @@ static void ThrowIfNotStarted(DistributedApplication app)
         }
     }
 
-    static EndpointReference? GetEndpointOrDefault(IResourceWithEndpoints resourceWithEndpoints, string endpointName)
+    static EndpointReference? GetEndpointOrDefault(IResourceWithEndpoints resourceWithEndpoints, string endpointName, NetworkIdentifier? networkIdentifier = default)
     {
-        var reference = resourceWithEndpoints.GetEndpoint(endpointName);
+        var reference = resourceWithEndpoints.GetEndpoint(endpointName, networkIdentifier ?? KnownNetworkIdentifiers.LocalhostNetwork);
 
         return reference.IsAllocated ? reference : null;
     }

src/Aspire.Hosting/ApplicationModel/ConnectionStringReference.cs

@@ -23,22 +23,12 @@ public class ConnectionStringReference(IResourceWithConnectionString resource, b
 
     ValueTask<string?> IValueProvider.GetValueAsync(CancellationToken cancellationToken)
     {
-        return this.GetNetworkValueAsync(null, cancellationToken);
+        return Resource.GetValueAsync(cancellationToken);
     }
 
-    ValueTask<string?> IValueProvider.GetValueAsync(ValueProviderContext context, CancellationToken cancellationToken)
+    async ValueTask<string?> IValueProvider.GetValueAsync(ValueProviderContext context, CancellationToken cancellationToken)
     {
-        return context.Network switch
-        {
-            NetworkIdentifier networkContext => GetNetworkValueAsync(networkContext, cancellationToken),
-            _ => GetNetworkValueAsync(null, cancellationToken)
-        };
-    }
-
-    private async ValueTask<string?> GetNetworkValueAsync(NetworkIdentifier? networkContext, CancellationToken cancellationToken)
-    {
-        ValueProviderContext vpc = new() { Network = networkContext };
-        var value = await Resource.GetValueAsync(vpc, cancellationToken).ConfigureAwait(false);
+        var value = await Resource.GetValueAsync(context, cancellationToken).ConfigureAwait(false);
 
         if (string.IsNullOrEmpty(value) && !Optional)
         {

src/Aspire.Hosting/ApplicationModel/EndpointReference.cs

@@ -15,7 +15,7 @@ public sealed class EndpointReference : IManifestExpressionProvider, IValueProvi
     // A reference to the endpoint annotation if it exists.
     private EndpointAnnotation? _endpointAnnotation;
     private bool? _isAllocated;
-    private readonly NetworkIdentifier _contextNetworkID;
+    private readonly NetworkIdentifier? _contextNetworkID;
 
     /// <summary>
     /// Gets the endpoint annotation associated with the endpoint reference.
@@ -71,7 +71,7 @@ public sealed class EndpointReference : IManifestExpressionProvider, IValueProvi
     /// The reference will be resolved in the context of this network, which may be different
     /// from the network associated with the default network of the referenced Endpoint.
     /// </summary>
-    public NetworkIdentifier ContextNetworkID => _contextNetworkID;
+    public NetworkIdentifier? ContextNetworkID => _contextNetworkID;
 
     /// <summary>
     /// Gets the specified property expression of the endpoint. Defaults to the URL if no property is specified.
@@ -156,7 +156,7 @@ public EndpointReferenceExpression Property(EndpointProperty property)
 
         foreach (var nes in endpointAnnotation.AllAllocatedEndpoints)
         {
-            if (StringComparers.NetworkID.Equals(nes.NetworkID, _contextNetworkID))
+            if (StringComparers.NetworkID.Equals(nes.NetworkID, _contextNetworkID ?? KnownNetworkIdentifiers.LocalhostNetwork))
             {
                 if (!nes.Snapshot.IsValueSet)
                 {
@@ -177,20 +177,20 @@ public EndpointReferenceExpression Property(EndpointProperty property)
     /// <param name="endpoint">The endpoint annotation.</param>
     /// <param name="contextNetworkID">The ID of the network that serves as the context for the EndpointReference.</param>
     /// <remarks>
-    /// Most Aspire resources are accessed in the context of the "localhost" network (host proceses calling other host processes,
-    /// or host processes calling container via mapped ports). This is why EndpointReference assumes this
-    /// context unless specified otherwise. However, for container-to-container, or container-to-host communication,
-    /// you must specify a container network context for the EndpointReference to be resolved correctly.
+    /// Most Aspire resources are accessed in the context of the "localhost" network (host processes calling other host processes,
+    /// or host processes calling container via mapped ports). If a <see cref="NetworkIdentifier"/> is specified, the <see cref="EndpointReference"/>
+    /// will always resolve in the context of that network. If the <see cref="NetworkIdentifier"/> is null, the reference will attempt to resolve itself
+    /// based on the context of the requesting resource.
     /// </remarks>
-    public EndpointReference(IResourceWithEndpoints owner, EndpointAnnotation endpoint, NetworkIdentifier? contextNetworkID = null)
+    public EndpointReference(IResourceWithEndpoints owner, EndpointAnnotation endpoint, NetworkIdentifier? contextNetworkID)
     {
         ArgumentNullException.ThrowIfNull(owner);
         ArgumentNullException.ThrowIfNull(endpoint);
 
         Resource = owner;
         EndpointName = endpoint.Name;
         _endpointAnnotation = endpoint;
-        _contextNetworkID = contextNetworkID ?? KnownNetworkIdentifiers.LocalhostNetwork;
+        _contextNetworkID = contextNetworkID;
     }
 
     /// <summary>
@@ -221,7 +221,7 @@ public EndpointReference(IResourceWithEndpoints owner, string endpointName, Netw
 
         Resource = owner;
         EndpointName = endpointName;
-        _contextNetworkID = contextNetworkID ?? KnownNetworkIdentifiers.LocalhostNetwork;
+        _contextNetworkID = contextNetworkID;
     }
 
     /// <summary>
@@ -265,7 +265,7 @@ public class EndpointReferenceExpression(EndpointReference endpointReference, En
     /// <exception cref="InvalidOperationException">Throws when the selected <see cref="EndpointProperty"/> enumeration is not known.</exception>
     public ValueTask<string?> GetValueAsync(CancellationToken cancellationToken = default)
     {
-        return GetNetworkValueAsync(null, cancellationToken);
+        return GetValueAsync(new(), cancellationToken);
     }
 
     /// <summary>
@@ -275,33 +275,25 @@ public class EndpointReferenceExpression(EndpointReference endpointReference, En
     /// <param name="cancellationToken">A <see cref="CancellationToken"/>.</param>
     /// <returns>A <see cref="string"/> containing the selected <see cref="EndpointProperty"/> value.</returns>
     /// <exception cref="InvalidOperationException">Throws when the selected <see cref="EndpointProperty"/> enumeration is not known.</exception>
-    public ValueTask<string?> GetValueAsync(ValueProviderContext context, CancellationToken cancellationToken = default)
+    public async ValueTask<string?> GetValueAsync(ValueProviderContext context, CancellationToken cancellationToken = default)
     {
-        return context.Network switch
-        {
-            NetworkIdentifier networkID => GetNetworkValueAsync(networkID, cancellationToken),
-            _ => GetNetworkValueAsync(null, cancellationToken)
-        };
-    }
+        // If the EndpointReference was for a specific network context, then use that. Otherwise, use the network context from the ValueProviderContext.
+        // This allows the EndpointReference to be resolved in the context of the caller's network if it was not explicitly set.
+        var networkContext = Endpoint.ContextNetworkID ?? context.GetNetworkIdentifier();
 
-
-    private async ValueTask<string?> GetNetworkValueAsync(NetworkIdentifier? context, CancellationToken cancellationToken = default)
-    {
         return Property switch
         {
             EndpointProperty.Scheme => new(Endpoint.Scheme),
-            EndpointProperty.IPV4Host when context is null || context == KnownNetworkIdentifiers.LocalhostNetwork => "127.0.0.1",
+            EndpointProperty.IPV4Host when networkContext == KnownNetworkIdentifiers.LocalhostNetwork => "127.0.0.1",
             EndpointProperty.TargetPort when Endpoint.TargetPort is int port => new(port.ToString(CultureInfo.InvariantCulture)),
             _ => await ResolveValueWithAllocatedAddress().ConfigureAwait(false)
         };
 
         async ValueTask<string?> ResolveValueWithAllocatedAddress()
         {
-            var effectiveContext = context ?? Endpoint.ContextNetworkID;
-
             // We are going to take the first snapshot that matches the context network ID. In general there might be multiple endpoints for a single service,
             // and in future we might need some sort of policy to choose between them, but for now we just take the first one.
-            var nes = Endpoint.EndpointAnnotation.AllAllocatedEndpoints.Where(nes => nes.NetworkID == effectiveContext).FirstOrDefault();
+            var nes = Endpoint.EndpointAnnotation.AllAllocatedEndpoints.Where(nes => nes.NetworkID == networkContext).FirstOrDefault();
             if (nes is null)
             {
                 return null;

src/Aspire.Hosting/ApplicationModel/ExpressionResolver.cs

@@ -95,13 +95,14 @@ async Task<ResolvedValue> ResolveConnectionStringReferenceAsync(ConnectionString
     /// </summary>
     async ValueTask<ResolvedValue> ResolveInternalAsync(object? value, ValueProviderContext context)
     {
+        var networkContext = context.GetNetworkIdentifier();
         return value switch
         {
             ConnectionStringReference cs => await ResolveConnectionStringReferenceAsync(cs, context).ConfigureAwait(false),
             IResourceWithConnectionString cs and not ConnectionStringParameterResource => await ResolveInternalAsync(cs.ConnectionStringExpression, context).ConfigureAwait(false),
             ReferenceExpression ex => await EvalExpressionAsync(ex, context).ConfigureAwait(false),
-            EndpointReference er when context.Network == KnownNetworkIdentifiers.DefaultAspireContainerNetwork => new ResolvedValue(await ResolveInContainerContextAsync(er, EndpointProperty.Url, context).ConfigureAwait(false), false),
-            EndpointReferenceExpression ep when context.Network == KnownNetworkIdentifiers.DefaultAspireContainerNetwork => new ResolvedValue(await ResolveInContainerContextAsync(ep.Endpoint, ep.Property, context).ConfigureAwait(false), false),
+            EndpointReference er when networkContext == KnownNetworkIdentifiers.DefaultAspireContainerNetwork => new ResolvedValue(await ResolveInContainerContextAsync(er, EndpointProperty.Url, context).ConfigureAwait(false), false),
+            EndpointReferenceExpression ep when networkContext == KnownNetworkIdentifiers.DefaultAspireContainerNetwork => new ResolvedValue(await ResolveInContainerContextAsync(ep.Endpoint, ep.Property, context).ConfigureAwait(false), false),
             IValueProvider vp => await EvalValueProvider(vp, context).ConfigureAwait(false),
             _ => throw new NotImplementedException()
         };