Add business metrics for observability and endpoint override

aws/codegen-aws-sdk/src/main/kotlin/software/amazon/smithy/rustsdk/AwsCodegenDecorator.kt

@@ -46,6 +46,7 @@ val DECORATORS: List<ClientCodegenDecorator> =
             CredentialsProviderDecorator(),
             RegionDecorator(),
             RequireEndpointRules(),
+            EndpointOverrideDecorator(),
             UserAgentDecorator(),
             SigV4AuthDecorator(),
             HttpRequestChecksumDecorator(),
@@ -65,6 +66,7 @@ val DECORATORS: List<ClientCodegenDecorator> =
             AwsRequestIdDecorator(),
             DisabledAuthDecorator(),
             RecursionDetectionDecorator(),
+            ObservabilityDetectionDecorator(),
             InvocationIdDecorator(),
             RetryInformationHeaderDecorator(),
             RemoveDefaultsDecorator(),

aws/codegen-aws-sdk/src/main/kotlin/software/amazon/smithy/rustsdk/EndpointOverrideDecorator.kt

@@ -0,0 +1,49 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.rustsdk
+
+import software.amazon.smithy.rust.codegen.client.smithy.ClientCodegenContext
+import software.amazon.smithy.rust.codegen.client.smithy.customize.ClientCodegenDecorator
+import software.amazon.smithy.rust.codegen.client.smithy.generators.ServiceRuntimePluginCustomization
+import software.amazon.smithy.rust.codegen.client.smithy.generators.ServiceRuntimePluginSection
+import software.amazon.smithy.rust.codegen.core.rustlang.Writable
+import software.amazon.smithy.rust.codegen.core.rustlang.rust
+import software.amazon.smithy.rust.codegen.core.rustlang.writable
+
+/**
+ * Registers the EndpointOverrideInterceptor to detect custom endpoint usage for business metrics
+ */
+class EndpointOverrideDecorator : ClientCodegenDecorator {
+    override val name: String = "EndpointOverride"
+    override val order: Byte = 0
+
+    override fun serviceRuntimePluginCustomizations(
+        codegenContext: ClientCodegenContext,
+        baseCustomizations: List<ServiceRuntimePluginCustomization>,
+    ): List<ServiceRuntimePluginCustomization> =
+        baseCustomizations + EndpointOverrideRuntimePluginCustomization(codegenContext)
+
+    private class EndpointOverrideRuntimePluginCustomization(codegenContext: ClientCodegenContext) :
+        ServiceRuntimePluginCustomization() {
+        private val runtimeConfig = codegenContext.runtimeConfig
+        private val awsRuntime = AwsRuntimeType.awsRuntime(runtimeConfig)
+
+        override fun section(section: ServiceRuntimePluginSection): Writable =
+            writable {
+                when (section) {
+                    is ServiceRuntimePluginSection.RegisterRuntimeComponents -> {
+                        section.registerInterceptor(this) {
+                            rust(
+                                "#T::new()",
+                                awsRuntime.resolve("endpoint_override::EndpointOverrideInterceptor"),
+                            )
+                        }
+                    }
+                    else -> emptySection
+                }
+            }
+    }
+}

aws/codegen-aws-sdk/src/main/kotlin/software/amazon/smithy/rustsdk/ObservabilityDetectionDecorator.kt

@@ -0,0 +1,49 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.rustsdk
+
+import software.amazon.smithy.rust.codegen.client.smithy.ClientCodegenContext
+import software.amazon.smithy.rust.codegen.client.smithy.customize.ClientCodegenDecorator
+import software.amazon.smithy.rust.codegen.client.smithy.generators.ServiceRuntimePluginCustomization
+import software.amazon.smithy.rust.codegen.client.smithy.generators.ServiceRuntimePluginSection
+import software.amazon.smithy.rust.codegen.core.rustlang.Writable
+import software.amazon.smithy.rust.codegen.core.rustlang.rust
+import software.amazon.smithy.rust.codegen.core.rustlang.writable
+
+/**
+ * Registers the ObservabilityDetectionInterceptor to detect observability feature usage for business metrics
+ */
+class ObservabilityDetectionDecorator : ClientCodegenDecorator {
+    override val name: String = "ObservabilityDetection"
+    override val order: Byte = 0
+
+    override fun serviceRuntimePluginCustomizations(
+        codegenContext: ClientCodegenContext,
+        baseCustomizations: List<ServiceRuntimePluginCustomization>,
+    ): List<ServiceRuntimePluginCustomization> =
+        baseCustomizations + ObservabilityDetectionRuntimePluginCustomization(codegenContext)
+
+    private class ObservabilityDetectionRuntimePluginCustomization(codegenContext: ClientCodegenContext) :
+        ServiceRuntimePluginCustomization() {
+        private val runtimeConfig = codegenContext.runtimeConfig
+        private val awsRuntime = AwsRuntimeType.awsRuntime(runtimeConfig)
+
+        override fun section(section: ServiceRuntimePluginSection): Writable =
+            writable {
+                when (section) {
+                    is ServiceRuntimePluginSection.RegisterRuntimeComponents -> {
+                        section.registerInterceptor(this) {
+                            rust(
+                                "#T::new()",
+                                awsRuntime.resolve("observability_detection::ObservabilityDetectionInterceptor"),
+                            )
+                        }
+                    }
+                    else -> emptySection
+                }
+            }
+    }
+}

aws/codegen-aws-sdk/src/test/kotlin/software/amazon/smithy/rustsdk/EndpointOverrideDecoratorTest.kt

@@ -0,0 +1,148 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.rustsdk
+
+import org.junit.jupiter.api.Test
+import software.amazon.smithy.rust.codegen.core.rustlang.rustTemplate
+import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType
+import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType.Companion.preludeScope
+import software.amazon.smithy.rust.codegen.core.testutil.asSmithyModel
+import software.amazon.smithy.rust.codegen.core.testutil.integrationTest
+import software.amazon.smithy.rust.codegen.core.testutil.tokioTest
+
+class EndpointOverrideDecoratorTest {
+    companion object {
+        private const val PREFIX = "\$version: \"2\""
+        val model =
+            """
+            $PREFIX
+            namespace test
+
+            use aws.api#service
+            use aws.auth#sigv4
+            use aws.protocols#restJson1
+            use smithy.rules#endpointRuleSet
+
+            @service(sdkId: "dontcare")
+            @restJson1
+            @sigv4(name: "dontcare")
+            @auth([sigv4])
+            @endpointRuleSet({
+                "version": "1.0",
+                "rules": [{ "type": "endpoint", "conditions": [], "endpoint": { "url": "https://example.com" } }],
+                "parameters": {
+                    "Region": { "required": false, "type": "String", "builtIn": "AWS::Region" },
+                }
+            })
+            service TestService {
+                version: "2023-01-01",
+                operations: [SomeOperation]
+            }
+
+            @http(uri: "/SomeOperation", method: "GET")
+            @optionalAuth
+            operation SomeOperation {
+                input: SomeInput,
+                output: SomeOutput
+            }
+
+            @input
+            structure SomeInput {}
+
+            @output
+            structure SomeOutput {}
+            """.asSmithyModel()
+    }
+
+    @Test
+    fun `decorator is registered in AwsCodegenDecorator list`() {
+        // Verify that EndpointOverrideDecorator is in the DECORATORS list
+        val decoratorNames = DECORATORS.map { it.name }
+        assert(decoratorNames.contains("EndpointOverride")) {
+            "EndpointOverrideDecorator should be registered in DECORATORS list"
+        }
+    }
+
+    @Test
+    fun `endpoint override interceptor adds business metric to user agent`() {
+        val testParams =
+            awsIntegrationTestParams().copy(
+                additionalSettings =
+                    awsIntegrationTestParams().additionalSettings.toBuilder()
+                        .withMember(
+                            "codegen",
+                            software.amazon.smithy.model.node.ObjectNode.builder()
+                                .withMember("includeFluentClient", false)
+                                .withMember("includeEndpointUrlConfig", true)
+                                .build(),
+                        )
+                        .build(),
+            )
+
+        awsSdkIntegrationTest(model, testParams) { context, rustCrate ->
+            val rc = context.runtimeConfig
+            val moduleName = context.moduleUseName()
+            rustCrate.integrationTest("endpoint_override_functional") {
+                tokioTest("interceptor_adds_metric_when_endpoint_overridden") {
+                    rustTemplate(
+                        """
+                        use $moduleName::config::Region;
+                        use $moduleName::{Client, Config};
+
+                        let (http_client, rcvr) = #{capture_request}(#{None});
+                        let config = Config::builder()
+                            .region(Region::new("us-east-1"))
+                            .endpoint_url("https://custom.example.com")
+                            .http_client(http_client.clone())
+                            .build();
+                        let client = Client::from_conf(config);
+
+                        // CRITICAL: Actually make a request
+                        let _ = client.some_operation().send().await;
+
+                        // Capture and verify the request
+                        let request = rcvr.expect_request();
+
+                        // Verify endpoint was overridden
+                        let uri = request.uri().to_string();
+                        assert!(
+                            uri.starts_with("https://custom.example.com"),
+                            "Expected custom endpoint, got: {}",
+                            uri
+                        );
+
+                        // Verify x-amz-user-agent contains business metric 'N' (endpoint override)
+                        // The metric appears in the business-metrics section as "m/..." with comma-separated IDs
+                        let x_amz_user_agent = request.headers()
+                            .get("x-amz-user-agent")
+                            .expect("x-amz-user-agent header missing");
+
+                        // Extract the business metrics section (starts with "m/")
+                        let has_endpoint_override_metric = x_amz_user_agent
+                            .split_whitespace()
+                            .find(|part| part.starts_with("m/"))
+                            .map(|metrics| {
+                                // Check if 'N' appears as a metric ID (either alone or in a comma-separated list)
+                                metrics.strip_prefix("m/")
+                                    .map(|ids| ids.split(',').any(|id| id == "N"))
+                                    .unwrap_or(false)
+                            })
+                            .unwrap_or(false);
+
+                        assert!(
+                            has_endpoint_override_metric,
+                            "Expected metric ID 'N' (endpoint override) in x-amz-user-agent business metrics, got: {}",
+                            x_amz_user_agent
+                        );
+                        """,
+                        *preludeScope,
+                        "capture_request" to RuntimeType.captureRequest(rc),
+                    )
+                }
+            }
+        }
+    }
+}