Add interceptor for collecting client metrics (#4021)

## Motivation and Context
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## Description
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## Testing
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## Checklist
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- [ ] For changes to the smithy-rs codegen or runtime crates, I have
created a changelog entry Markdown file in the `.changelog` directory,
specifying "client," "server," or both in the `applies_to` key.
- [ ] For changes to the AWS SDK, generated SDK code, or SDK runtime
crates, I have created a changelog entry Markdown file in the
`.changelog` directory, specifying "aws-sdk-rust" in the `applies_to`
key.

----

_By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice._

Author: landonxjames

aws/rust-runtime/Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "aws-config"
-version = "1.6.0"
+version = "1.6.1"
 authors = [
     "AWS Rust SDK Team <aws-sdk-rust@amazon.com>",
     "Russell Cohen <rcoh@amazon.com>",

aws/rust-runtime/aws-config/Cargo.lock

@@ -12,14 +12,15 @@ use crate::json_credentials::{parse_json_credentials, JsonCredentials, Refreshab
 use crate::provider_config::ProviderConfig;
 use aws_credential_types::provider::{self, error::CredentialsError};
 use aws_credential_types::Credentials;
+use aws_smithy_runtime::client::metrics::MetricsRuntimePlugin;
 use aws_smithy_runtime::client::orchestrator::operation::Operation;
 use aws_smithy_runtime::client::retries::classifiers::{
     HttpStatusCodeClassifier, TransientErrorClassifier,
 };
 use aws_smithy_runtime_api::client::http::HttpConnectorSettings;
 use aws_smithy_runtime_api::client::interceptors::context::{Error, InterceptorContext};
 use aws_smithy_runtime_api::client::orchestrator::{
-    HttpResponse, OrchestratorError, SensitiveOutput,
+    HttpResponse, Metadata, OrchestratorError, SensitiveOutput,
 };
 use aws_smithy_runtime_api::client::result::SdkError;
 use aws_smithy_runtime_api::client::retries::classifiers::ClassifyRetry;
@@ -88,6 +89,7 @@ impl Builder {
         path: impl Into<String>,
     ) -> HttpCredentialProvider {
         let provider_config = self.provider_config.unwrap_or_default();
+        let path = path.into();
 
         let mut builder = Operation::builder()
             .service_name("HttpCredentialProvider")
@@ -105,7 +107,15 @@ impl Builder {
                 let mut layer = Layer::new("SensitiveOutput");
                 layer.store_put(SensitiveOutput);
                 layer.freeze()
-            }));
+            }))
+            .runtime_plugin(
+                MetricsRuntimePlugin::builder()
+                    .with_scope("aws_config::http_credential_provider")
+                    .with_time_source(provider_config.time_source())
+                    .with_metadata(Metadata::new(path.clone(), provider_name))
+                    .build()
+                    .expect("All required fields have been set"),
+            );
         if let Some(http_client) = provider_config.http_client() {
             builder = builder.http_client(http_client);
         }
@@ -126,7 +136,6 @@ impl Builder {
         } else {
             builder = builder.no_retry();
         }
-        let path = path.into();
         let operation = builder
             .serializer(move |input: HttpProviderAuth| {
                 let mut http_req = http::Request::builder()

aws/rust-runtime/aws-config/Cargo.toml

@@ -12,6 +12,7 @@ use crate::imds::client::token::TokenRuntimePlugin;
 use crate::provider_config::ProviderConfig;
 use crate::PKG_VERSION;
 use aws_runtime::user_agent::{ApiMetadata, AwsUserAgent, UserAgentInterceptor};
+use aws_smithy_runtime::client::metrics::MetricsRuntimePlugin;
 use aws_smithy_runtime::client::orchestrator::operation::Operation;
 use aws_smithy_runtime::client::retries::strategy::StandardRetryStrategy;
 use aws_smithy_runtime_api::box_error::BoxError;
@@ -21,7 +22,7 @@ use aws_smithy_runtime_api::client::endpoint::{
 };
 use aws_smithy_runtime_api::client::interceptors::context::InterceptorContext;
 use aws_smithy_runtime_api::client::orchestrator::{
-    HttpRequest, OrchestratorError, SensitiveOutput,
+    HttpRequest, Metadata, OrchestratorError, SensitiveOutput,
 };
 use aws_smithy_runtime_api::client::result::ConnectorError;
 use aws_smithy_runtime_api::client::result::SdkError;
@@ -476,6 +477,14 @@ impl Builder {
                 common_plugin,
                 self.token_ttl.unwrap_or(DEFAULT_TOKEN_TTL),
             ))
+            .runtime_plugin(
+                MetricsRuntimePlugin::builder()
+                    .with_scope("aws_config::imds_credentials")
+                    .with_time_source(config.time_source())
+                    .with_metadata(Metadata::new("get_credentials", "imds"))
+                    .build()
+                    .expect("All required fields have been set"),
+            )
             .with_connection_poisoning()
             .serializer(|path| {
                 Ok(HttpRequest::try_from(

aws/rust-runtime/aws-config/src/http_credential_provider.rs

@@ -11,6 +11,7 @@ members = [
     "iam",
     "kms",
     "lambda",
+    "metrics",
     "no-default-features",
     "polly",
     "qldbsession",

aws/rust-runtime/aws-config/src/imds/client.rs

@@ -0,0 +1,25 @@
+# This Cargo.toml is unused in generated code. It exists solely to enable these tests to compile in-situ
+[package]
+name = "metrics-tests"
+version = "0.1.0"
+authors = ["AWS Rust SDK Team <aws-sdk-rust@amazon.com>"]
+edition = "2021"
+license = "Apache-2.0"
+repository = "https://github.com/smithy-lang/smithy-rs"
+publish = false
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dev-dependencies]
+aws-config = { path = "../../build/aws-sdk/sdk/aws-config", features = ["test-util", "behavior-version-latest"] }
+aws-sdk-dynamodb = { path = "../../build/aws-sdk/sdk/dynamodb", features = ["test-util", "behavior-version-latest"] }
+aws-sdk-s3 = { path = "../../build/aws-sdk/sdk/s3", features = ["test-util", "behavior-version-latest"] }
+aws-smithy-observability = { path = "../../build/aws-sdk/sdk/aws-smithy-observability" }
+aws-smithy-observability-otel = { path = "../../build/aws-sdk/sdk/aws-smithy-observability-otel" }
+aws-smithy-runtime = { path = "../../build/aws-sdk/sdk/aws-smithy-runtime", features = ["client", "test-util"]}
+aws-smithy-types = { path = "../../build/aws-sdk/sdk/aws-smithy-types" }
+http = "0.2.0"
+opentelemetry = { version = "0.26.0", features = ["metrics"] }
+opentelemetry_sdk = { version = "0.26.0", features = ["metrics", "testing"] }
+serial_test = "3.1.1"
+tokio = { version = "1.23.1", features = ["full", "test-util"] }