Move resource creation in ResourceReadyEvent event

playground/CosmosEndToEnd/CosmosEndToEnd.AppHost/Program.cs

@@ -5,7 +5,7 @@
 
 #pragma warning disable ASPIRECOSMOS001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
 var db = builder.AddAzureCosmosDB("cosmos")
-                .WithDatabase("db", database => database.Containers.Add(new("entries", "/Id")))
+                .WithDatabase("db", database => database.Containers.Add(new("entries", "/id")))
                 .RunAsPreviewEmulator(e => e.WithDataExplorer());
 #pragma warning restore ASPIRECOSMOS001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
 

src/Aspire.Hosting.Azure.CosmosDB/Aspire.Hosting.Azure.CosmosDB.csproj

@@ -21,6 +21,7 @@
     <ProjectReference Include="..\Aspire.Hosting.Azure\Aspire.Hosting.Azure.csproj" />
     <PackageReference Include="Azure.Identity" />
     <PackageReference Include="Microsoft.Azure.Cosmos" />
+    <PackageReference Include="AspNetCore.HealthChecks.CosmosDb" />
     <PackageReference Include="Newtonsoft.Json" /> <!-- Required by Microsoft.Azure.Cosmos -->
     <PackageReference Include="Azure.Provisioning" />
     <PackageReference Include="Azure.Provisioning.CosmosDB" />

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

@@ -14,7 +14,6 @@
 using Azure.Provisioning.KeyVault;
 using Microsoft.Azure.Cosmos;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Diagnostics.HealthChecks;
 
 namespace Aspire.Hosting;
 
@@ -97,18 +96,32 @@ private static IResourceBuilder<AzureCosmosDBResource> RunAsEmulator(this IResou
             cosmosClient = CreateCosmosClient(connectionString);
         });
 
+        builder.ApplicationBuilder.Eventing.Subscribe<ResourceReadyEvent>(builder.Resource, async (@event, ct) =>
+        {
+            if (cosmosClient is null)
+            {
+                throw new InvalidOperationException("CosmosClient is not initialized.");
+            }
+
+            await cosmosClient.ReadAccountAsync().WaitAsync(ct).ConfigureAwait(false);
+
+            foreach (var database in builder.Resource.Databases)
+            {
+                var db = (await cosmosClient.CreateDatabaseIfNotExistsAsync(database.Name, cancellationToken: ct).ConfigureAwait(false)).Database;
+
+                foreach (var container in database.Containers)
+                {
+                    await db.CreateContainerIfNotExistsAsync(container.Name, container.PartitionKeyPath, cancellationToken: ct).ConfigureAwait(false);
+                }
+            }
+        });
+
         // Use custom health check that also seeds the databases and containers
         var healthCheckKey = $"{builder.Resource.Name}_check";
-        builder.ApplicationBuilder.Services.AddHealthChecks().Add(
-            new HealthCheckRegistration(
-                name: healthCheckKey,
-                new AzureCosmosDBEmulatorHealthCheck(
-                    () => cosmosClient ?? throw new InvalidOperationException("CosmosClient is not initialized."),
-                    builder.Resource.Databases.ToArray
-                ),
-            failureStatus: null,
-            tags: null)
-        );
+        builder.ApplicationBuilder.Services.AddHealthChecks().AddAzureCosmosDB(
+            sp => cosmosClient ?? throw new InvalidOperationException("CosmosClient is not initialized."),
+            name: healthCheckKey
+            );
 
         builder.WithHealthCheck(healthCheckKey);