feat(engines): add usable_by for filtering valid service subtypes for resource access

engines/terraform/platform.go

@@ -51,7 +51,7 @@ type PlatformSpec struct {
 	TopicBlueprints      map[string]*ResourceBlueprint `json:"topics,omitempty" yaml:"topics,omitempty"`
 	DatabaseBlueprints   map[string]*ResourceBlueprint `json:"databases,omitempty" yaml:"databases,omitempty"`
 	EntrypointBlueprints map[string]*ResourceBlueprint `json:"entrypoints" yaml:"entrypoints"`
-	InfraSpecs map[string]*ResourceBlueprint `json:"infra" yaml:"infra"`
+	InfraSpecs           map[string]*ResourceBlueprint `json:"infra" yaml:"infra"`
 
 	libraryReplacements map[libraryID]libraryVersion
 }
@@ -371,6 +371,7 @@ type ResourceBlueprint struct {
 	Properties map[string]interface{} `json:"properties" yaml:"properties"`
 	DependsOn  []string               `json:"depends_on" yaml:"depends_on,omitempty"`
 	Variables  map[string]Variable    `json:"variables" yaml:"variables,omitempty"`
+	UsableBy   []string               `json:"usable_by,omitempty" yaml:"usable_by,omitempty"`
 }
 
 func (r *ResourceBlueprint) ResolvePlugin(platform *PlatformSpec) (*Plugin, error) {
@@ -393,6 +394,22 @@ func (r *ResourceBlueprint) ResolvePlugin(platform *PlatformSpec) (*Plugin, erro
 	return &Plugin{Library: *lib, Name: r.Source.Plugin}, nil
 }
 
+func (r *ResourceBlueprint) ValidateServiceAccess(serviceSubtype, resourceName, resourceType string) error {
+	// All service types are allowed if useable_by is empty (backward compatible)
+	if len(r.UsableBy) == 0 {
+		return nil
+	}
+
+	if !slices.Contains(r.UsableBy, serviceSubtype) {
+		return fmt.Errorf(
+			"%s '%s' cannot be accessed by service subtype '%s': this %s blueprint is only usable by service types: %v",
+			resourceType, resourceName, serviceSubtype, resourceType, r.UsableBy,
+		)
+	}
+
+	return nil
+}
+
 type IdentitiesBlueprint struct {
 	Identities []ResourceBlueprint `json:"identities" yaml:"identities"`
 }

engines/terraform/platform_test.go

@@ -0,0 +1,98 @@
+package terraform
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestResourceBlueprint_ValidateServiceAccess(t *testing.T) {
+	tests := []struct {
+		name            string
+		usableBy        []string
+		serviceSubtype  string
+		resourceName    string
+		resourceType    string
+		expectError     bool
+		errorContains   string
+	}{
+		{
+			name:           "empty usable_by allows all service types",
+			usableBy:       []string{},
+			serviceSubtype: "lambda",
+			resourceName:   "my_bucket",
+			resourceType:   "bucket",
+			expectError:    false,
+		},
+		{
+			name:           "nil usable_by allows all service types",
+			usableBy:       nil,
+			serviceSubtype: "fargate",
+			resourceName:   "my_database",
+			resourceType:   "database",
+			expectError:    false,
+		},
+		{
+			name:           "service subtype in allowed list succeeds",
+			usableBy:       []string{"web", "worker", "api"},
+			serviceSubtype: "web",
+			resourceName:   "users_db",
+			resourceType:   "database",
+			expectError:    false,
+		},
+		{
+			name:           "service subtype not in allowed list fails",
+			usableBy:       []string{"web", "worker"},
+			serviceSubtype: "lambda",
+			resourceName:   "users_db",
+			resourceType:   "database",
+			expectError:    true,
+			errorContains:  "database 'users_db' cannot be accessed by service subtype 'lambda'",
+		},
+		{
+			name:           "single allowed service type succeeds",
+			usableBy:       []string{"fargate"},
+			serviceSubtype: "fargate",
+			resourceName:   "assets",
+			resourceType:   "bucket",
+			expectError:    false,
+		},
+		{
+			name:           "single allowed service type with different subtype fails",
+			usableBy:       []string{"fargate"},
+			serviceSubtype: "lambda",
+			resourceName:   "assets",
+			resourceType:   "bucket",
+			expectError:    true,
+			errorContains:  "bucket 'assets' cannot be accessed by service subtype 'lambda'",
+		},
+		{
+			name:           "error message includes allowed types list",
+			usableBy:       []string{"web", "worker", "cron"},
+			serviceSubtype: "lambda",
+			resourceName:   "cache_db",
+			resourceType:   "database",
+			expectError:    true,
+			errorContains:  "only usable by service types: [web worker cron]",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			blueprint := &ResourceBlueprint{
+				UsableBy: tt.usableBy,
+			}
+
+			err := blueprint.ValidateServiceAccess(tt.serviceSubtype, tt.resourceName, tt.resourceType)
+
+			if tt.expectError {
+				assert.Error(t, err)
+				if tt.errorContains != "" {
+					assert.Contains(t, err.Error(), tt.errorContains)
+				}
+			} else {
+				assert.NoError(t, err)
+			}
+		})
+	}
+}

engines/terraform/resource_handler.go

@@ -152,6 +152,15 @@ func (td *TerraformDeployment) processBucketResources(appSpec *app_spec_schema.A
 					return nil, fmt.Errorf("could not give access to bucket %s: service %s not found", intentName, serviceName)
 				}
 
+				// Validate that this service subtype is allowed to access the bucket
+				serviceIntent, ok := appSpec.ServiceIntents[serviceName]
+				if !ok {
+					return nil, fmt.Errorf("could not validate access to bucket %s: service %s not found in application spec", intentName, serviceName)
+				}
+				if err := spec.ValidateServiceAccess(serviceIntent.GetSubType(), intentName, "bucket"); err != nil {
+					return nil, err
+				}
+
 				servicesInput[serviceName] = map[string]interface{}{
 					"actions":    jsii.Strings(expandedActions...),
 					"identities": idMap,
@@ -237,6 +246,15 @@ func (td *TerraformDeployment) processDatabaseResources(appSpec *app_spec_schema
 					return nil, fmt.Errorf("could not give access to database %s: service %s not found", intentName, serviceName)
 				}
 
+				// Validate that this service subtype is allowed to access the database
+				serviceIntent, ok := appSpec.ServiceIntents[serviceName]
+				if !ok {
+					return nil, fmt.Errorf("could not validate access to database %s: service %s not found in application spec", intentName, serviceName)
+				}
+				if err := spec.ValidateServiceAccess(serviceIntent.GetSubType(), intentName, "database"); err != nil {
+					return nil, err
+				}
+
 				servicesInput[serviceName] = map[string]interface{}{
 					"actions":    jsii.Strings(expandedActions...),
 					"identities": idMap,