Add operation metadata to property bag just before sending request through middleware

CHANGELOG.next.toml

@@ -52,3 +52,12 @@ message = "Fix bug that can cause panics in paginators"
 references = ["smithy-rs#1903", "smithy-rs#1902"]
 meta = { "breaking" = false, "tada" = false, "bug" = true, "target" = "client"}
 author = "rcoh"
+
+[[smithy-rs]]
+message = """
+Operation metadata is now added to the property bag before sending requests allowing middlewares to behave
+differently depending on the operation being sent.
+"""
+references = ["smithy-rs#1919"]
+meta = { "breaking" = false, "tada" = false, "bug" = false, "target" = "client"}
+author = "Velfi"

aws/rust-runtime/aws-inlineable/tests/middleware_e2e_test.rs

@@ -19,6 +19,7 @@ use aws_http::retry::AwsResponseRetryClassifier;
 use aws_http::user_agent::AwsUserAgent;
 use aws_inlineable::middleware::DefaultMiddleware;
 use aws_sig_auth::signer::OperationSigningConfig;
+use aws_smithy_client::erase::DynConnector;
 
 use aws_smithy_client::test_connection::TestConnection;
 use aws_smithy_http::body::SdkBody;
@@ -112,6 +113,7 @@ fn test_operation() -> Operation<TestOperationParser, AwsResponseRetryClassifier
     .unwrap();
     Operation::new(req, TestOperationParser)
         .with_retry_classifier(AwsResponseRetryClassifier::new())
+        .with_metadata(operation::Metadata::new("test-op", "test-service"))
 }
 
 #[cfg(any(feature = "native-tls", feature = "rustls"))]
@@ -148,3 +150,39 @@ async fn e2e_test() {
 
     conn.assert_requests_match(&[]);
 }
+
+#[tokio::test]
+async fn test_operation_metadata_is_available_to_middlewares() {
+    let conn = TestConnection::new(vec![(
+        http::Request::builder()
+            .header(USER_AGENT, "aws-sdk-rust/0.123.test os/windows/XPSP3 lang/rust/1.50.0")
+            .header("x-amz-user-agent", "aws-sdk-rust/0.123.test api/test-service/0.123 os/windows/XPSP3 lang/rust/1.50.0")
+            .header(AUTHORIZATION, "AWS4-HMAC-SHA256 Credential=access_key/20210215/test-region/test-service-signing/aws4_request, SignedHeaders=host;x-amz-date;x-amz-user-agent, Signature=da249491d7fe3da22c2e09cbf910f37aa5b079a3cedceff8403d0b18a7bfab75")
+            .header("x-amz-date", "20210215T184017Z")
+            .uri(Uri::from_static("https://test-service.test-region.amazonaws.com/"))
+            .body(SdkBody::from("request body")).unwrap(),
+        http::Response::builder()
+            .status(200)
+            .body("response body")
+            .unwrap(),
+    )]);
+    let client = aws_smithy_client::Client::builder()
+        .middleware_fn(|req| {
+            let metadata = req
+                .properties()
+                .get::<operation::Metadata>()
+                .cloned()
+                .unwrap();
+
+            assert_eq!("test-op", metadata.name());
+            assert_eq!("test-service", metadata.service());
+
+            req
+        })
+        .connector(DynConnector::new(conn))
+        .build();
+
+    let resp = client.call(test_operation()).await;
+    let resp = resp.expect("successful operation");
+    assert_eq!(resp, "Hello!");
+}

codegen-core/src/main/kotlin/software/amazon/smithy/rust/codegen/core/smithy/generators/protocol/MakeOperationGenerator.kt

@@ -71,7 +71,8 @@ open class MakeOperationGenerator(
     ) {
         val operationName = symbolProvider.toSymbol(shape).name
         val baseReturnType = buildOperationType(implBlockWriter, shape, customizations)
-        val returnType = "std::result::Result<$baseReturnType, ${implBlockWriter.format(runtimeConfig.operationBuildError())}>"
+        val returnType =
+            "std::result::Result<$baseReturnType, ${implBlockWriter.format(runtimeConfig.operationBuildError())}>"
         val outputSymbol = symbolProvider.toSymbol(shape)
 
         val takesOwnership = bodyGenerator.payloadMetadata(shape).takesOwnership
@@ -82,8 +83,10 @@ open class MakeOperationGenerator(
 
         implBlockWriter.docs("Consumes the builder and constructs an Operation<#D>", outputSymbol)
         Attribute.AllowUnusedMut.render(implBlockWriter) // For codegen simplicity
-        Attribute.Custom("allow(clippy::let_and_return)").render(implBlockWriter) // For codegen simplicity, allow `let x = ...; x`
-        Attribute.Custom("allow(clippy::needless_borrow)").render(implBlockWriter) // Allows builders that don’t consume the input borrow
+        Attribute.Custom("allow(clippy::let_and_return)")
+            .render(implBlockWriter) // For codegen simplicity, allow `let x = ...; x`
+        Attribute.Custom("allow(clippy::needless_borrow)")
+            .render(implBlockWriter) // Allows builders that don’t consume the input borrow
         implBlockWriter.rustBlockTemplate(
             "$fnType $functionName($self, _config: &#{config}::Config) -> $returnType",
             *codegenScope,

rust-runtime/aws-smithy-http-tower/src/parse_response.rs

@@ -88,7 +88,7 @@ where
     }
 
     fn call(&mut self, req: Operation<ResponseHandler, RetryPolicy>) -> Self::Future {
-        let (req, parts) = req.into_request_response();
+        let (mut req, parts) = req.into_request_response();
         let handler = parts.response_handler;
         // send_operation records the full request-response lifecycle.
         // NOTE: For operations that stream output, only the setup is captured in this span.
@@ -103,6 +103,7 @@ where
         if let Some(metadata) = parts.metadata {
             span.record("operation", &metadata.name());
             span.record("service", &metadata.service());
+            req.properties_mut().insert(metadata);
         }
         let resp = self.inner.call(req);
         let fut = async move {