Make it easier to choose Azure SQL SKU

src/Aspire.Hosting.Azure.Sql/AzureSqlDatabaseResource.cs

@@ -16,6 +16,11 @@ namespace Aspire.Hosting.Azure;
 public class AzureSqlDatabaseResource(string name, string databaseName, AzureSqlServerResource parent)
     : Resource(name), IResourceWithParent<AzureSqlServerResource>, IResourceWithConnectionString
 {
+    /// <summary>
+    /// SKU associated with the free offer
+    /// </summary>
+    internal const string FREE_DB_SKU = "GP_S_Gen5_2";
+
     /// <summary>
     /// Gets the parent Azure SQL Database (server) resource.
     /// </summary>
@@ -32,6 +37,11 @@ public class AzureSqlDatabaseResource(string name, string databaseName, AzureSql
     /// </summary>
     public string DatabaseName { get; } = ThrowIfNullOrEmpty(databaseName);
 
+    /// <summary>  
+    /// Gets or Sets the database SKU name  
+    /// </summary>  
+    public bool UseDefaultAzureSku { get; internal set; } // Default to false  
+
     /// <summary>
     /// Gets the inner SqlServerDatabaseResource resource.
     /// 
@@ -58,5 +68,4 @@ internal void SetInnerResource(SqlServerDatabaseResource innerResource)
 
         InnerResource = innerResource;
     }
-
 }

src/Aspire.Hosting.Azure.Sql/AzureSqlExtensions.cs

@@ -81,7 +81,7 @@ public static IResourceBuilder<AzureSqlServerResource> AddAzureSqlServer(this ID
         var configureInfrastructure = (AzureResourceInfrastructure infrastructure) =>
         {
             var azureResource = (AzureSqlServerResource)infrastructure.AspireResource;
-            CreateSqlServer(infrastructure, builder, azureResource.Databases);
+            CreateSqlServer(infrastructure, builder, azureResource.AzureSqlDatabases);
         };
 
         var resource = new AzureSqlServerResource(name, configureInfrastructure);
@@ -93,6 +93,7 @@ public static IResourceBuilder<AzureSqlServerResource> AddAzureSqlServer(this ID
 
     /// <summary>
     /// Adds an Azure SQL Database to the application model.
+    /// The Free Offer option will be used when deploying the resource in Azure
     /// </summary>
     /// <param name="builder">The builder for the Azure SQL resource.</param>
     /// <param name="name">The name of the resource. This name will be used as the connection string name when referenced in a dependency.</param>
@@ -109,7 +110,7 @@ public static IResourceBuilder<AzureSqlDatabaseResource> AddDatabase(this IResou
         var azureResource = builder.Resource;
         var azureSqlDatabase = new AzureSqlDatabaseResource(name, databaseName, azureResource);
 
-        builder.Resource.AddDatabase(name, databaseName);
+        builder.Resource.AddDatabase(azureSqlDatabase);
 
         if (azureResource.InnerResource is null)
         {
@@ -127,6 +128,18 @@ public static IResourceBuilder<AzureSqlDatabaseResource> AddDatabase(this IResou
         }
     }
 
+    /// <summary>
+    /// Configures the Azure SQL Database to be deployed use the default SKU provided by Azure.
+    /// Please be aware that the Azure default Sku might not take advantage of the free offer.
+    /// </summary>
+    /// <param name="builder">The builder for the Azure SQL resource.</param>
+    /// <returns>A reference to the <see cref="IResourceBuilder{T}"/>.</returns>
+    public static IResourceBuilder<AzureSqlDatabaseResource> WithDefaultAzureSku(this IResourceBuilder<AzureSqlDatabaseResource> builder)
+    {
+        builder.Resource.UseDefaultAzureSku = true;
+        return builder;
+    }
+
     /// <summary>
     /// Configures an Azure SQL Database (server) resource to run locally in a container.
     /// </summary>
@@ -171,14 +184,14 @@ public static IResourceBuilder<AzureSqlServerResource> RunAsContainer(this IReso
 
         azureResource.SetInnerResource(sqlContainer.Resource);
 
-        foreach (var database in azureResource.Databases)
+        foreach (var database in azureResource.AzureSqlDatabases)
         {
             if (!azureDatabases.TryGetValue(database.Key, out var existingDb))
             {
                 throw new InvalidOperationException($"Could not find a {nameof(AzureSqlDatabaseResource)} with name {database.Key}.");
             }
 
-            var innerDb = sqlContainer.AddDatabase(database.Key, database.Value);
+            var innerDb = sqlContainer.AddDatabase(database.Key, database.Value.DatabaseName);
             existingDb.SetInnerResource(innerDb.Resource);
         }
 
@@ -200,6 +213,55 @@ private static void CreateSqlServer(
         AzureResourceInfrastructure infrastructure,
         IDistributedApplicationBuilder distributedApplicationBuilder,
         IReadOnlyDictionary<string, string> databases)
+    {
+        var sqlServer = CreateSqlServerResourceOnly(infrastructure, distributedApplicationBuilder);
+
+        foreach (var database in databases)
+        {
+            var sqlDatabase = CreateAzureSQLDatabase(sqlServer, database.Key, database.Value);
+
+            infrastructure.Add(sqlDatabase);
+        }
+    }
+
+    private static void CreateSqlServer(
+        AzureResourceInfrastructure infrastructure,
+        IDistributedApplicationBuilder distributedApplicationBuilder,
+        IReadOnlyDictionary<string, AzureSqlDatabaseResource> databases)
+    {
+        var sqlServer = CreateSqlServerResourceOnly(infrastructure, distributedApplicationBuilder);
+
+        foreach (var database in databases)
+        {
+            var sqlDatabase = CreateAzureSQLDatabase(sqlServer, database.Key, database.Value.DatabaseName);
+
+            // Unless user specifically mention that they want to use the Azure defaults,
+            // an Azure SQL DB using the free option will be created
+            if (database.Value.UseDefaultAzureSku == false)
+            {
+                sqlDatabase.Sku = new SqlSku() { Name = AzureSqlDatabaseResource.FREE_DB_SKU };
+                sqlDatabase.UseFreeLimit = true;
+                sqlDatabase.FreeLimitExhaustionBehavior = FreeLimitExhaustionBehavior.AutoPause;
+            }
+
+            infrastructure.Add(sqlDatabase);
+        }
+    }
+
+    private static SqlDatabase CreateAzureSQLDatabase(SqlServer sqlServer, string databaseKey, string databaseName)
+    {
+        var bicepIdentifier = Infrastructure.NormalizeBicepIdentifier(databaseKey);
+        var sqlDatabase = new SqlDatabase(bicepIdentifier)
+        {
+            Parent = sqlServer,
+            Name = databaseName,
+        };
+
+        return sqlDatabase;
+    }
+
+    private static SqlServer CreateSqlServerResourceOnly(AzureResourceInfrastructure infrastructure,
+        IDistributedApplicationBuilder distributedApplicationBuilder)
     {
         var azureResource = (AzureSqlServerResource)infrastructure.AspireResource;
 
@@ -265,22 +327,12 @@ private static void CreateSqlServer(
             });
         }
 
-        foreach (var databaseNames in databases)
-        {
-            var bicepIdentifier = Infrastructure.NormalizeBicepIdentifier(databaseNames.Key);
-            var databaseName = databaseNames.Value;
-            var sqlDatabase = new SqlDatabase(bicepIdentifier)
-            {
-                Parent = sqlServer,
-                Name = databaseName
-            };
-            infrastructure.Add(sqlDatabase);
-        }
-
         infrastructure.Add(new ProvisioningOutput("sqlServerFqdn", typeof(string)) { Value = sqlServer.FullyQualifiedDomainName });
 
         // We need to output name to externalize role assignments.
         infrastructure.Add(new ProvisioningOutput("name", typeof(string)) { Value = sqlServer.Name });
+
+        return sqlServer;
     }
 
     internal static SqlServerAzureADAdministrator AddActiveDirectoryAdministrator(AzureResourceInfrastructure infra, SqlServer sqlServer, BicepValue<Guid> principalId, BicepValue<string> principalName)

src/Aspire.Hosting.Azure.Sql/AzureSqlServerResource.cs

@@ -12,7 +12,7 @@ namespace Aspire.Hosting.Azure;
 /// </summary>
 public class AzureSqlServerResource : AzureProvisioningResource, IResourceWithConnectionString
 {
-    private readonly Dictionary<string, string> _databases = new Dictionary<string, string>(StringComparers.ResourceName);
+    private readonly Dictionary<string, AzureSqlDatabaseResource> _databases = new Dictionary<string, AzureSqlDatabaseResource>(StringComparers.ResourceName);
     private readonly bool _createdWithInnerResource;
 
     /// <summary>
@@ -75,13 +75,21 @@ public ReferenceExpression ConnectionStringExpression
     public override ResourceAnnotationCollection Annotations => InnerResource?.Annotations ?? base.Annotations;
 
     /// <summary>
-    /// A dictionary where the key is the resource name and the value is the database name.
+    /// A dictionary where the key is the resource name and the value is the Azure SQL database resource.
     /// </summary>
-    public IReadOnlyDictionary<string, string> Databases => _databases;
+    public IReadOnlyDictionary<string, AzureSqlDatabaseResource> AzureSqlDatabases => _databases;
 
-    internal void AddDatabase(string name, string databaseName)
+    /// <summary>
+    /// A dictionary where the key is the resource name and the value is the Azure SQL database name.
+    /// </summary>
+    public IReadOnlyDictionary<string, string> Databases => _databases.ToDictionary(
+        kvp => kvp.Key,
+        kvp => kvp.Value.DatabaseName
+    );
+
+    internal void AddDatabase(AzureSqlDatabaseResource db)
     {
-        _databases.TryAdd(name, databaseName);
+        _databases.TryAdd(db.Name, db);
     }
 
     internal void SetInnerResource(SqlServerServerResource innerResource)

src/Aspire.Hosting.Azure.Sql/README.md

@@ -1,6 +1,6 @@
 # Aspire.Hosting.Azure.Sql library
 
-Provides extension methods and resource definitions for a .NET Aspire AppHost to configure Azure SQL Server.
+Provides extension methods and resource definitions for a .NET Aspire AppHost to configure Azure SQL DB.
 
 ## Getting started
 
@@ -54,6 +54,24 @@ The `WithReference` method configures a connection in the `MyService` project na
 builder.AddSqlServerClient("sqldata");
 ```
 
+## Azure SQL DB defaults
+
+Unless otherwise specified, the Azure SQL DB created will be a 2vCores General Purpose Serverless database (GP_S_Gen5_2) with the free offer enabled.
+
+Read more about the free offer here: [Deploy Azure SQL Database for free](https://learn.microsoft.com/azure/azure-sql/database/free-offer?view=azuresql)
+
+The free offer is configured so that when the maximum usage limit is reached, the database is stopped to avoid incurring in unexpected costs.
+
+If you don't want to use the free offer and instead deploy the database with the service level of your choice, specify the SKU name when adding the database resource:
+
+```csharp
+var sql = builder.AddAzureSqlServer("sql")
+                 .AddDatabase("db", "my-db-name").WithSku("HS_Gen5_2");
+
+var myService = builder.AddProject<Projects.MyService>()
+                       .WithReference(sql);
+```
+
 ## Additional documentation
 
 * https://learn.microsoft.com/dotnet/framework/data/adonet/sql/

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

@@ -21,9 +21,15 @@ public async Task AddAzureSqlServer(bool publishMode, bool useAcaInfrastructure)
 
         var sql = builder.AddAzureSqlServer("sql");
 
+        // database name same as the aspire resource name, free tier 
         sql.AddDatabase("db1");
+
+        // set the database name, free tier 
         sql.AddDatabase("db2", "db2Name");
 
+        // do not set any sku, use whatever is the default for Azure at that time
+        sql.AddDatabase("db3", "db3Name").WithDefaultAzureSku();
+
         if (useAcaInfrastructure)
         {
             builder.AddAzureContainerAppEnvironment("env");
@@ -130,12 +136,32 @@ param principalName string
             resource db1 'Microsoft.Sql/servers/databases@2021-11-01' = {
               name: 'db1'
               location: location
+              properties: {
+                freeLimitExhaustionBehavior: 'AutoPause'
+                useFreeLimit: true
+              }
+              sku: {
+                name: 'GP_S_Gen5_2'
+              }
               parent: sql
             }
 
             resource db2 'Microsoft.Sql/servers/databases@2021-11-01' = {
               name: 'db2Name'
               location: location
+              properties: {
+                freeLimitExhaustionBehavior: 'AutoPause'
+                useFreeLimit: true
+              }
+              sku: {
+                name: 'GP_S_Gen5_2'
+              }
+              parent: sql
+            }
+
+            resource db3 'Microsoft.Sql/servers/databases@2021-11-01' = {
+              name: 'db3Name'
+              location: location
               parent: sql
             }
 
@@ -158,11 +184,13 @@ public async Task AddAzureSqlServerRunAsContainerProducesCorrectConnectionString
 
         IResourceBuilder<AzureSqlDatabaseResource> db1 = null!;
         IResourceBuilder<AzureSqlDatabaseResource> db2 = null!;
+        IResourceBuilder<AzureSqlDatabaseResource> db3 = null!;
+
         if (addDbBeforeRunAsContainer)
         {
             db1 = sql.AddDatabase("db1");
             db2 = sql.AddDatabase("db2", "db2Name");
-
+            db3 = sql.AddDatabase("db3", "db3Name").WithDefaultAzureSku();
         }
         sql.RunAsContainer(c =>
         {
@@ -173,6 +201,7 @@ public async Task AddAzureSqlServerRunAsContainerProducesCorrectConnectionString
         {
             db1 = sql.AddDatabase("db1");
             db2 = sql.AddDatabase("db2", "db2Name");
+            db3 = sql.AddDatabase("db3", "db3Name").WithDefaultAzureSku();
         }
 
         Assert.True(sql.Resource.IsContainer(), "The resource should now be a container resource.");
@@ -187,6 +216,10 @@ public async Task AddAzureSqlServerRunAsContainerProducesCorrectConnectionString
         var db2ConnectionString = await db2.Resource.ConnectionStringExpression.GetValueAsync(CancellationToken.None);
         Assert.StartsWith("Server=127.0.0.1,12455;User ID=sa;Password=", db2ConnectionString);
         Assert.EndsWith(";TrustServerCertificate=true;Database=db2Name", db2ConnectionString);
+
+        var db3ConnectionString = await db3.Resource.ConnectionStringExpression.GetValueAsync(CancellationToken.None);
+        Assert.StartsWith("Server=127.0.0.1,12455;User ID=sa;Password=", db3ConnectionString);
+        Assert.EndsWith(";TrustServerCertificate=true;Database=db3Name", db3ConnectionString);
     }
 
     [Theory]
@@ -198,12 +231,16 @@ public async Task AddAzureSqlServerRunAsContainerProducesCorrectPasswordAndPort(
 
         var sql = builder.AddAzureSqlServer("sql");
         var pass = builder.AddParameter("pass", "p@ssw0rd1");
+
         IResourceBuilder<AzureSqlDatabaseResource> db1 = null!;
         IResourceBuilder<AzureSqlDatabaseResource> db2 = null!;
+        IResourceBuilder<AzureSqlDatabaseResource> db3 = null!;
+
         if (addDbBeforeRunAsContainer)
         {
             db1 = sql.AddDatabase("db1");
             db2 = sql.AddDatabase("db2", "db2Name");
+            db3 = sql.AddDatabase("db3", "db3Name").WithDefaultAzureSku();
         }
 
         IResourceBuilder<SqlServerServerResource>? innerSql = null;
@@ -221,6 +258,7 @@ public async Task AddAzureSqlServerRunAsContainerProducesCorrectPasswordAndPort(
         {
             db1 = sql.AddDatabase("db1");
             db2 = sql.AddDatabase("db2", "db2Name");
+            db3 = sql.AddDatabase("db3", "db3Name").WithDefaultAzureSku();
         }
 
         var endpoint = Assert.Single(innerSql.Resource.Annotations.OfType<EndpointAnnotation>());
@@ -241,6 +279,9 @@ public async Task AddAzureSqlServerRunAsContainerProducesCorrectPasswordAndPort(
 
         var db2ConnectionString = await db2.Resource.ConnectionStringExpression.GetValueAsync(CancellationToken.None);
         Assert.StartsWith("Server=127.0.0.1,12455;User ID=sa;Password=p@ssw0rd1;TrustServerCertificate=true;Database=db2Name", db2ConnectionString);
+
+        var db3ConnectionString = await db3.Resource.ConnectionStringExpression.GetValueAsync(CancellationToken.None);
+        Assert.StartsWith("Server=127.0.0.1,12455;User ID=sa;Password=p@ssw0rd1;TrustServerCertificate=true;Database=db3Name", db3ConnectionString);
     }
 
     [Theory]
@@ -301,11 +342,31 @@ public void RunAsContainerAppliesAnnotationsCorrectly(bool annotationsBefore, bo
         Assert.Single(dbAnnotations);
     }
 
+    [Fact]
+    public void VerifyDefaultAzureSku()
+    {
+        using var builder = TestDistributedApplicationBuilder.Create();
+
+        var sql = builder.AddAzureSqlServer("sql");
+
+        // database name same as the aspire resource name, free tier 
+        var db1 = sql.AddDatabase("db1");
+        Assert.False(db1.Resource.UseDefaultAzureSku);
+
+        // set the database name, free tier 
+        var db2 = sql.AddDatabase("db2", "db2Name");
+        Assert.False(db2.Resource.UseDefaultAzureSku);
+
+        // set the database name, do not use the free offer
+        var db3 = sql.AddDatabase("db3", "db3Name").WithDefaultAzureSku();
+        Assert.True(db3.Resource.UseDefaultAzureSku);
+    }
+
     private sealed class Dummy1Annotation : IResourceAnnotation
     {
     }
 
     private sealed class Dummy2Annotation : IResourceAnnotation
     {
-    }
+    }    
 }