Allow Azure Functions to reference CosmosDB databases and containers

Resources that participate in Azure Functions need to implement IResourceWithAzureFunctionsConfig. Add this to the child resources in CosmosDB.

For now, only the top-level account information is passed via connection string and config properties.

Contributes to #7407

src/Aspire.Hosting.Azure.CosmosDB/AzureCosmosDBContainerResource.cs

@@ -11,7 +11,7 @@ namespace Aspire.Hosting.Azure;
 /// <remarks>
 /// Use <see cref="AzureProvisioningResourceExtensions.ConfigureInfrastructure{T}(ApplicationModel.IResourceBuilder{T}, Action{AzureResourceInfrastructure})"/> to configure specific <see cref="Azure.Provisioning"/> properties.
 /// </remarks>
-public class AzureCosmosDBContainerResource : Resource, IResourceWithParent<AzureCosmosDBDatabaseResource>, IResourceWithConnectionString
+public class AzureCosmosDBContainerResource : Resource, IResourceWithParent<AzureCosmosDBDatabaseResource>, IResourceWithConnectionString, IResourceWithAzureFunctionsConfig
 {
     /// <summary>
     /// Initializes a new instance of the <see cref="AzureCosmosDBContainerResource"/> class.
@@ -42,4 +42,8 @@ public AzureCosmosDBContainerResource(string name, string containerName, string
     /// Gets the connection string expression for the Azure Cosmos DB Database Container.
     /// </summary>
     public ReferenceExpression ConnectionStringExpression => Parent.ConnectionStringExpression;
+
+    // ensure Azure Functions projects can WithReference a CosmosDB database container
+    void IResourceWithAzureFunctionsConfig.ApplyAzureFunctionsConfiguration(IDictionary<string, object> target, string connectionName) =>
+        ((IResourceWithAzureFunctionsConfig)Parent).ApplyAzureFunctionsConfiguration(target, connectionName);
 }

src/Aspire.Hosting.Azure.CosmosDB/AzureCosmosDBDatabaseResource.cs

@@ -11,7 +11,7 @@ namespace Aspire.Hosting.Azure;
 /// <remarks>
 /// Use <see cref="AzureProvisioningResourceExtensions.ConfigureInfrastructure{T}(ApplicationModel.IResourceBuilder{T}, Action{AzureResourceInfrastructure})"/> to configure specific <see cref="Azure.Provisioning"/> properties.
 /// </remarks>
-public class AzureCosmosDBDatabaseResource : Resource, IResourceWithParent<AzureCosmosDBResource>, IResourceWithConnectionString
+public class AzureCosmosDBDatabaseResource : Resource, IResourceWithParent<AzureCosmosDBResource>, IResourceWithConnectionString, IResourceWithAzureFunctionsConfig
 {
     /// <summary>
     /// Initializes a new instance of the <see cref="AzureCosmosDBDatabaseResource"/> class.
@@ -41,4 +41,8 @@ public AzureCosmosDBDatabaseResource(string name, string databaseName, AzureCosm
     /// Gets the connection string expression for the Azure Cosmos DB database.
     /// </summary>
     public ReferenceExpression ConnectionStringExpression => Parent.ConnectionStringExpression;
+
+    // ensure Azure Functions projects can WithReference a CosmosDB database
+    void IResourceWithAzureFunctionsConfig.ApplyAzureFunctionsConfiguration(IDictionary<string, object> target, string connectionName) =>
+        ((IResourceWithAzureFunctionsConfig)Parent).ApplyAzureFunctionsConfiguration(target, connectionName);
 }

tests/Aspire.Hosting.Azure.Tests/AzureCosmosDBExtensionsTests.cs

@@ -87,4 +87,48 @@ public void AddAzureCosmosDBWithDataExplorer()
         Assert.Throws<NotSupportedException>(() => cosmos2.RunAsEmulator(e => e.WithDataExplorer()));
 #pragma warning restore ASPIRECOSMOS001 // RunAsPreviewEmulator is experimental
     }
+
+    [Fact]
+    public void AzureCosmosDBHasCorrectConnectionStrings()
+    {
+        using var builder = TestDistributedApplicationBuilder.Create();
+
+        var cosmos = builder.AddAzureCosmosDB("cosmos");
+        var db1 = cosmos.AddCosmosDatabase("db1");
+        var container1 = db1.AddContainer("container1", "id");
+
+        // database and container should have the same connection string as the cosmos account, for now.
+        // In the future, we can add the database and container info to the connection string.
+        Assert.Equal("{cosmos.outputs.connectionString}", cosmos.Resource.ConnectionStringExpression.ValueExpression);
+        Assert.Equal("{cosmos.outputs.connectionString}", db1.Resource.ConnectionStringExpression.ValueExpression);
+        Assert.Equal("{cosmos.outputs.connectionString}", container1.Resource.ConnectionStringExpression.ValueExpression);
+    }
+
+    [Fact]
+    public void AzureCosmosDBAppliesAzureFunctionsConfiguration()
+    {
+        using var builder = TestDistributedApplicationBuilder.Create();
+
+        var cosmos = builder.AddAzureCosmosDB("cosmos");
+        var db1 = cosmos.AddCosmosDatabase("db1");
+        var container1 = db1.AddContainer("container1", "id");
+
+        var target = new Dictionary<string, object>();
+        ((IResourceWithAzureFunctionsConfig)cosmos.Resource).ApplyAzureFunctionsConfiguration(target, "cosmos");
+        Assert.Collection(target.Keys.OrderBy(k => k),
+            k => Assert.Equal("Aspire__Microsoft__Azure__Cosmos__cosmos__AccountEndpoint", k),
+            k => Assert.Equal("cosmos__accountEndpoint", k));
+
+        target.Clear();
+        ((IResourceWithAzureFunctionsConfig)db1.Resource).ApplyAzureFunctionsConfiguration(target, "db1");
+        Assert.Collection(target.Keys.OrderBy(k => k),
+            k => Assert.Equal("Aspire__Microsoft__Azure__Cosmos__db1__AccountEndpoint", k),
+            k => Assert.Equal("db1__accountEndpoint", k));
+
+        target.Clear();
+        ((IResourceWithAzureFunctionsConfig)container1.Resource).ApplyAzureFunctionsConfiguration(target, "container1");
+        Assert.Collection(target.Keys.OrderBy(k => k),
+            k => Assert.Equal("Aspire__Microsoft__Azure__Cosmos__container1__AccountEndpoint", k),
+            k => Assert.Equal("container1__accountEndpoint", k));
+    }
 }