Add EndpointOverrideRuntimePlugin to aws-runtime

Provides the runtime plugin that the generated code references
to track endpoint override metrics.

Author: vcjana

aws/rust-runtime/aws-runtime/src/endpoint_override.rs

@@ -0,0 +1,35 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+//! Endpoint override detection for business metrics tracking
+
+use aws_smithy_runtime_api::client::runtime_plugin::RuntimePlugin;
+use aws_smithy_types::config_bag::{FrozenLayer, Layer};
+
+use crate::sdk_feature::AwsSdkFeature;
+
+/// Runtime plugin that tracks when a custom endpoint URL has been configured.
+#[derive(Debug, Default)]
+#[non_exhaustive]
+pub struct EndpointOverrideRuntimePlugin {
+    config: Option<FrozenLayer>,
+}
+
+impl EndpointOverrideRuntimePlugin {
+    /// Creates a new `EndpointOverrideRuntimePlugin` with the endpoint override feature flag set
+    pub fn new_with_feature_flag() -> Self {
+        let mut layer = Layer::new("endpoint_override");
+        layer.store_append(AwsSdkFeature::EndpointOverride);
+        Self {
+            config: Some(layer.freeze()),
+        }
+    }
+}
+
+impl RuntimePlugin for EndpointOverrideRuntimePlugin {
+    fn config(&self) -> Option<FrozenLayer> {
+        self.config.clone()
+    }
+}

aws/rust-runtime/aws-runtime/src/lib.rs

@@ -26,6 +26,9 @@ pub mod content_encoding;
 /// Supporting code for recursion detection in the AWS SDK.
 pub mod recursion_detection;
 
+/// Supporting code for endpoint override detection in the AWS SDK.
+pub mod endpoint_override;
+
 /// Supporting code for user agent headers in the AWS SDK.
 pub mod user_agent;
 

aws/rust-runtime/aws-runtime/src/sdk_feature.rs

@@ -24,6 +24,8 @@ pub enum AwsSdkFeature {
     SsoLoginDevice,
     /// Calling an SSO-OIDC operation as part of the SSO login flow, when using the OAuth2.0 authorization code grant
     SsoLoginAuth,
+    /// Indicates that a custom endpoint URL was configured
+    EndpointOverride,
 }
 
 impl Storable for AwsSdkFeature {