Add experimental feature to enable runtime values in tags and SKU

docs/experimental-features.md

@@ -60,6 +60,21 @@ Enables the 'resourceInfo' function for simplified code generation.
 
 Enables the type for a parameter or output to be of type resource to make it easier to pass resource references between modules. This feature is only partially implemented. See [Simplifying resource referencing](https://github.com/azure/bicep/issues/2245).
 
+### `runtimeValuesInTagsAndSku`
+
+Allows the use of runtime values (such as this.existingResource()) in `tags` and `sku` properties. By default, these properties are flagged as deploy-time constants, meaning they cannot reference runtime resource properties. Enabling this feature relaxes that restriction. (Note: This feature will not work until the backend service support has been deployed)
+
+```bicep
+resource example 'Microsoft...' = {
+  name: 'example'
+  location: resourceGroup().location
+  sku: {
+    name: this.existingResource().?sku.name ?? 'Standard'
+  }
+  tags: this.existingResource().?tags ?? {}
+}
+```
+
 ### `sourceMapping`
 
 Enables basic source mapping to map an error location returned in the ARM template layer back to the relevant location in the Bicep file.

src/Bicep.Core.UnitTests/Configuration/ConfigurationManagerTests.cs

@@ -115,7 +115,8 @@ public void GetBuiltInConfiguration_NoParameter_ReturnsBuiltInConfigurationWithA
           "resourceInfoCodegen": false,
           "userDefinedConstraints": false,
           "deployCommands": false,
-          "patch": false
+          "patch": false,
+          "runtimeValuesInTagsAndSku": false
         },
         "formatting": {
           "indentKind": "Space",
@@ -201,7 +202,8 @@ public void GetBuiltInConfiguration_DisableAllAnalyzers_ReturnsBuiltInConfigurat
           "moduleExtensionConfigs": false,
           "userDefinedConstraints": false,
           "deployCommands": false,
-          "patch": false
+          "patch": false,
+          "runtimeValuesInTagsAndSku": false
         },
         "formatting": {
           "indentKind": "Space",
@@ -309,7 +311,8 @@ public void GetBuiltInConfiguration_DisableAnalyzers_ReturnsBuiltInConfiguration
           "moduleExtensionConfigs": false,
           "userDefinedConstraints": false,
           "deployCommands": false,
-          "patch": false
+          "patch": false,
+          "runtimeValuesInTagsAndSku": false
         },
         "formatting": {
           "indentKind": "Space",
@@ -395,7 +398,8 @@ public void GetBuiltInConfiguration_EnableExperimentalFeature_ReturnsBuiltInConf
                 ModuleExtensionConfigs: false,
                 UserDefinedConstraints: false,
                 DeployCommands: false,
-                Patch: false);
+                Patch: false,
+                RuntimeValuesInTagsAndSku: false);
 
             configuration.WithExperimentalFeaturesEnabled(experimentalFeaturesEnabled).Should().HaveContents(/*lang=json,strict*/ """
             {
@@ -482,7 +486,8 @@ public void GetBuiltInConfiguration_EnableExperimentalFeature_ReturnsBuiltInConf
                 "moduleExtensionConfigs": false,
                 "userDefinedConstraints": false,
                 "deployCommands": false,
-                "patch": false
+                "patch": false,
+                "runtimeValuesInTagsAndSku": false
             },
             "formatting": {
                 "indentKind": "Space",
@@ -838,7 +843,8 @@ public void GetConfiguration_ValidCustomConfiguration_OverridesBuiltInConfigurat
                     "moduleExtensionConfigs": false,
                     "userDefinedConstraints": false,
                     "deployCommands": false,
-                    "patch": false
+                    "patch": false,
+                    "runtimeValuesInTagsAndSku": false
                   },
                   "formatting": {
                     "indentKind": "Space",

src/Bicep.Core.UnitTests/Features/FeatureProviderOverrides.cs

@@ -25,7 +25,8 @@ public record FeatureProviderOverrides(
     bool? ModuleExtensionConfigsEnabled = default,
     bool? UserDefinedConstraintsEnabled = default,
     bool? DeployCommandsEnabled = default,
-    bool? PatchEnabled = default)
+    bool? PatchEnabled = default,
+    bool? RuntimeValuesInTagsAndSkuEnabled = default)
 {
     public FeatureProviderOverrides(
         TestContext testContext,
@@ -45,7 +46,8 @@ public FeatureProviderOverrides(
         bool? ModuleExtensionConfigsEnabled = default,
         bool? UserDefinedConstraintsEnabled = default,
         bool? DeployCommandsEnabled = default,
-        bool? PatchEnabled = default) : this(
+        bool? PatchEnabled = default,
+        bool? RuntimeValuesInTagsAndSkuEnabled = default) : this(
             FileHelper.GetCacheRootDirectory(testContext),
             RegistryEnabled,
             OciEnabled,
@@ -63,7 +65,8 @@ public FeatureProviderOverrides(
             ModuleExtensionConfigsEnabled,
             UserDefinedConstraintsEnabled,
             DeployCommandsEnabled,
-            PatchEnabled)
+            PatchEnabled,
+            RuntimeValuesInTagsAndSkuEnabled)
     { }
 }
 

src/Bicep.Core.UnitTests/Features/OverriddenFeatureProvider.cs

@@ -48,4 +48,6 @@ public OverriddenFeatureProvider(IFeatureProvider features, FeatureProviderOverr
     public bool DeployCommandsEnabled => overrides.DeployCommandsEnabled ?? features.DeployCommandsEnabled;
 
     public bool PatchEnabled => overrides.PatchEnabled ?? features.PatchEnabled;
+
+    public bool RuntimeValuesInTagsAndSkuEnabled => overrides.RuntimeValuesInTagsAndSkuEnabled ?? features.RuntimeValuesInTagsAndSkuEnabled;
 }

src/Bicep.Core.UnitTests/Semantics/Namespaces/ThisNamespaceTests.cs

@@ -534,5 +534,155 @@ public void ThisNamespace_ForLoopNamedThis_ShouldSucceed()
                 template.Should().HaveValueAtPath("$.resources[0].name", "[format('testStorage{0}', range(0, 2)[copyIndex()])]");
             }
         }
+
+        [TestMethod]
+        public void ThisNamespace_ExistingResourceInTags_WithFeatureEnabled_ShouldSucceed()
+        {
+            var services = new ServiceBuilder().WithFeatureOverrides(new(TestContext, RuntimeValuesInTagsAndSkuEnabled: true));
+            var result = CompilationHelper.Compile(services, @"
+resource testResource 'Microsoft.Storage/storageAccounts@2021-04-01' = {
+  name: 'testStorage'
+  location: 'westus'
+  sku: {
+    name: 'Standard_LRS'
+  }
+  kind: 'StorageV2'
+  tags: {
+    previousAccessTier: this.existingResource().?properties.accessTier ?? 'unknown'
+  }
+  properties: {
+    allowBlobPublicAccess: this.exists()
+  }
+}
+");
+
+            result.Should().NotHaveAnyDiagnostics();
+
+            using (new AssertionScope())
+            {
+                var template = result.Template;
+
+                template.Should().HaveValueAtPath("$.resources.testResource.tags.previousAccessTier", "[coalesce(tryGet(target('full'), 'properties', 'accessTier'), 'unknown')]");
+                template.Should().HaveValueAtPath("$.resources.testResource.properties.allowBlobPublicAccess", "[not(empty(target('full')))]");
+                template.Should().HaveValueAtPath("$.languageVersion", "2.1-experimental");
+            }
+        }
+
+        [TestMethod]
+        public void ThisNamespace_ExistingResourceInSku_WithFeatureEnabled_ShouldSucceed()
+        {
+            var services = new ServiceBuilder().WithFeatureOverrides(new(TestContext, RuntimeValuesInTagsAndSkuEnabled: true));
+            var result = CompilationHelper.Compile(services, @"
+resource testResource 'Microsoft.Storage/storageAccounts@2021-04-01' = {
+  name: 'testStorage'
+  location: 'westus'
+  sku: {
+    name: this.existingResource().?sku.name ?? 'Standard_LRS'
+  }
+  kind: 'StorageV2'
+  properties: {
+    allowBlobPublicAccess: this.exists()
+  }
+}
+");
+
+            result.Should().NotHaveAnyDiagnostics();
+
+            using (new AssertionScope())
+            {
+                var template = result.Template;
+
+                template.Should().HaveValueAtPath("$.resources.testResource.sku.name", "[coalesce(tryGet(target('full'), 'sku', 'name'), 'Standard_LRS')]");
+                template.Should().HaveValueAtPath("$.languageVersion", "2.1-experimental");
+            }
+        }
+
+        [TestMethod]
+        public void ThisNamespace_ExistingResourceInTags_WithFeatureDisabled_ShouldFail()
+        {
+            var services = new ServiceBuilder().WithFeatureOverrides(new(TestContext, RuntimeValuesInTagsAndSkuEnabled: false));
+            var result = CompilationHelper.Compile(services, @"
+resource testResource 'Microsoft.Storage/storageAccounts@2021-04-01' = {
+  name: 'testStorage'
+  location: 'westus'
+  sku: {
+    name: 'Standard_LRS'
+  }
+  kind: 'StorageV2'
+  tags: {
+    previousAccessTier: this.existingResource().?properties.accessTier ?? 'unknown'
+  }
+  properties: {
+    allowBlobPublicAccess: this.exists()
+  }
+}
+");
+
+            result.ExcludingLinterDiagnostics().Should().HaveDiagnostics(new[]
+            {
+                ("BCP120", DiagnosticLevel.Error, "This expression is being used in an assignment to the \"tags\" property of the \"Microsoft.Storage/storageAccounts\" type, which requires a value that can be calculated at the start of the deployment."),
+            });
+        }
+
+        [TestMethod]
+        public void ThisNamespace_ExistingResourceInTagsAndSku_WithFeatureEnabled_OtherDtcPropertiesStillEnforced()
+        {
+            var services = new ServiceBuilder().WithFeatureOverrides(new(TestContext, RuntimeValuesInTagsAndSkuEnabled: true));
+            var result = CompilationHelper.Compile(services, @"
+resource testResource 'Microsoft.Storage/storageAccounts@2021-04-01' = {
+  name: this.exists() ? 'testStorage' : 'defaultStorage'
+  location: 'westus'
+  sku: {
+    name: this.existingResource().?sku.name ?? 'Standard_LRS'
+  }
+  kind: 'StorageV2'
+  tags: {
+    previousAccessTier: this.existingResource().?properties.accessTier ?? 'unknown'
+  }
+  properties: {
+    allowBlobPublicAccess: this.exists()
+  }
+}
+");
+
+            result.ExcludingLinterDiagnostics().Should().HaveDiagnostics(new[]
+            {
+                ("BCP120", DiagnosticLevel.Error, "This expression is being used in an assignment to the \"name\" property of the \"Microsoft.Storage/storageAccounts\" type, which requires a value that can be calculated at the start of the deployment."),
+            });
+        }
+
+        [TestMethod]
+        public void ThisNamespace_ExistingResourceInTagsAndSku_ForLoop_WithFeatureEnabled_ShouldSucceed()
+        {
+            var services = new ServiceBuilder().WithFeatureOverrides(new(TestContext, RuntimeValuesInTagsAndSkuEnabled: true));
+            var result = CompilationHelper.Compile(services, @"
+resource testResource 'Microsoft.Storage/storageAccounts@2021-04-01' = [for i in range(0, 3): {
+  name: 'testStorage-${i}'
+  location: 'westus'
+  sku: {
+    name: this.existingResource().?sku.name ?? 'Standard_LRS'
+  }
+  kind: 'StorageV2'
+  tags: {
+    previousAccessTier: this.existingResource().?properties.accessTier ?? 'unknown'
+  }
+  properties: {
+    allowBlobPublicAccess: this.exists()
+  }
+}]
+");
+
+            result.Should().NotHaveAnyDiagnostics();
+
+            using (new AssertionScope())
+            {
+                var template = result.Template;
+
+                template.Should().HaveValueAtPath("$.resources.testResource.tags.previousAccessTier", "[coalesce(tryGet(target('full'), 'properties', 'accessTier'), 'unknown')]");
+                template.Should().HaveValueAtPath("$.resources.testResource.sku.name", "[coalesce(tryGet(target('full'), 'sku', 'name'), 'Standard_LRS')]");
+                template.Should().HaveValueAtPath("$.resources.testResource.properties.allowBlobPublicAccess", "[not(empty(target('full')))]");
+                template.Should().HaveValueAtPath("$.languageVersion", "2.1-experimental");
+            }
+        }
     }
 }

src/Bicep.Core/Configuration/ExperimentalFeaturesEnabled.cs

@@ -23,7 +23,8 @@ public record ExperimentalFeaturesEnabled(
     bool ModuleExtensionConfigs,
     bool UserDefinedConstraints,
     bool DeployCommands,
-    bool Patch)
+    bool Patch,
+    bool RuntimeValuesInTagsAndSku)
 {
     public static ExperimentalFeaturesEnabled Bind(JsonElement element)
         => element.ToNonNullObject<ExperimentalFeaturesEnabled>();
@@ -44,5 +45,6 @@ public static ExperimentalFeaturesEnabled Bind(JsonElement element)
         ModuleExtensionConfigs: false,
         UserDefinedConstraints: false,
         DeployCommands: false,
-        Patch: false);
+        Patch: false,
+        RuntimeValuesInTagsAndSku: false);
 }

src/Bicep.Core/Features/FeatureProvider.cs

@@ -56,6 +56,8 @@ public FeatureProvider(RootConfiguration configuration, IFileExplorer fileExplor
 
         public bool PatchEnabled => configuration.ExperimentalFeaturesEnabled.Patch;
 
+        public bool RuntimeValuesInTagsAndSkuEnabled => configuration.ExperimentalFeaturesEnabled.RuntimeValuesInTagsAndSku;
+
         private static bool ReadBooleanEnvVar(string envVar, bool defaultValue)
             => bool.TryParse(Environment.GetEnvironmentVariable(envVar), out var value) ? value : defaultValue;
 

src/Bicep.Core/Features/IFeatureProvider.cs

@@ -39,6 +39,8 @@ public interface IFeatureProvider
 
     bool PatchEnabled { get; }
 
+    bool RuntimeValuesInTagsAndSkuEnabled { get; }
+
     IEnumerable<(string name, bool impactsCompilation, bool usesExperimentalArmEngineFeature)> EnabledFeatureMetadata
     {
         get
@@ -59,6 +61,7 @@ public interface IFeatureProvider
                 (ModuleExtensionConfigsEnabled, "Enable defining extension configs for modules", true, true),
                 (UserDefinedConstraintsEnabled, "Enable @validate() decorator", true, true),
                 (DeployCommandsEnabled, "Enable deploy commands", true, true),
+                (RuntimeValuesInTagsAndSkuEnabled, "Enable runtime values in tags and SKU", true, true),
             })
             {
                 if (enabled)

src/Bicep.Core/Features/RecordBasedFeatureProvider.cs

@@ -26,5 +26,6 @@ public class RecordBasedFeatureProvider(ExperimentalFeaturesEnabled features) :
         public bool UserDefinedConstraintsEnabled => features.UserDefinedConstraints;
         public bool DeployCommandsEnabled => features.DeployCommands;
         public bool PatchEnabled => features.Patch;
+        public bool RuntimeValuesInTagsAndSkuEnabled => features.RuntimeValuesInTagsAndSku;
     }
 }

src/Bicep.Core/TypeSystem/DeclaredTypeManager.cs

@@ -2309,6 +2309,11 @@ private TypeSymbol GetResourceTypeFromString(TextSpan span, string stringContent
                 flags |= ResourceTypeGenerationFlags.HasParentDefined;
             }
 
+            if (features.RuntimeValuesInTagsAndSkuEnabled)
+            {
+                flags |= ResourceTypeGenerationFlags.PermitRuntimeValuesInTagsAndSku;
+            }
+
             return (flags, parentType as ResourceType);
         }
     }

src/Bicep.Core/TypeSystem/Providers/Az/AzResourceTypeProvider.cs

@@ -23,6 +23,8 @@ public class AzResourceTypeProvider : ResourceTypeProviderBase, IResourceTypePro
         public const string ResourceNamePropertyName = "name";
         public const string ResourceTypePropertyName = "type";
         public const string ResourceApiVersionPropertyName = "apiVersion";
+        public const string ResourceTagsPropertyName = "tags";
+        public const string ResourceSkuPropertyName = "sku";
 
         public const string ResourceTypeDeployments = "Microsoft.Resources/deployments";
         public const string ResourceTypeResourceGroup = "Microsoft.Resources/resourceGroups";
@@ -58,10 +60,10 @@ public static readonly ImmutableSortedSet<string> ReadWriteDeployTimeConstantPro
             "extendedLocation",
             "zones",
             "plan",
-            "sku",
+            ResourceSkuPropertyName,
             "identity",
             "managedByExtended",
-            "tags",
+            ResourceTagsPropertyName,
             "asserts",
         ];
 
@@ -308,11 +310,20 @@ static NamedTypeProperty UpdateFlags(NamedTypeProperty typeProperty, TypePropert
                     properties = properties.SetItem(LanguageConstants.ResourceScopePropertyName, scopeProperty);
                 }
 
+                var permitRuntimeValuesInTagsAndSku = flags.HasFlag(ResourceTypeGenerationFlags.PermitRuntimeValuesInTagsAndSku);
+
                 // TODO: move this to the type library.
                 foreach (var propertyName in WriteOnlyDeployTimeConstantPropertyNames)
                 {
                     if (properties.TryGetValue(propertyName, out var typeProperty))
                     {
+                        if (permitRuntimeValuesInTagsAndSku &&
+                            (propertyName == ResourceTagsPropertyName || propertyName == ResourceSkuPropertyName))
+                        {
+                            // The experimental feature allows runtime values in 'tags' and 'sku', so skip marking them as deploy-time constant.
+                            continue;
+                        }
+
                         // Update tags for deploy-time constant properties that are not readable at deploy-time.
                         properties = properties.SetItem(propertyName, UpdateFlags(typeProperty, typeProperty.Flags | TypePropertyFlags.DeployTimeConstant));
                     }

src/Bicep.Core/TypeSystem/ResourceTypeGenerationFlags.cs

@@ -27,5 +27,10 @@ public enum ResourceTypeGenerationFlags
         /// Generating a definition for a syntactically nested resource. Do not use this flag for resources that need the "parent" property.
         /// </summary>
         NestedResource = 1 << 2,
+
+        /// <summary>
+        /// Do not mark the top-level 'tags' and 'sku' properties as deploy-time constant, allowing runtime values to be assigned to them.
+        /// </summary>
+        PermitRuntimeValuesInTagsAndSku = 1 << 3,
     }
 }