Add cloudwatch metrics (cloudwatch) & example (#554)

* Add cloudwatch metrics (cloudwatch)

* remove unused dependencies

aws/sdk/build.gradle.kts

@@ -80,6 +80,7 @@ val tier1Services = setOf(
     "sqs",
     "ssm",
     "sts",
+    "cloudwatch",
     "ecr",
     "eks"
 )

aws/sdk/examples/cloudwatch/Cargo.toml

+[package]
+name = "cloudwatch-code-examples"
+version = "0.1.0"
+authors = ["AWS Rust SDK Team <aws-sdk-rust@amazon.com>", "Russell Cohen <rcoh@amazon.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+cloudwatch = { package = "aws-sdk-cloudwatch", path = "../../build/aws-sdk/cloudwatch" }
+tokio = { version = "1", features = ["full"] }
+tracing-subscriber = { version = "0.2", features = ["fmt"] }

aws/sdk/examples/cloudwatch/src/bin/list-metrics.rs

+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+
+use cloudwatch::Client;
+
+#[tokio::main]
+async fn main() -> Result<(), cloudwatch::Error> {
+    tracing_subscriber::fmt::init();
+
+    let client = Client::from_env();
+    let rsp = client.list_metrics().send().await?;
+    let metrics = rsp.metrics.unwrap_or_default();
+    println!("found {} metric(s)", metrics.len());
+    for metric in metrics {
+        println!("metric: {:?}", metric);
+    }
+    Ok(())
+}