feat(rt): ECS credential provider (#353)

Author: kggilmer

aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/auth/credentials/EcsCredentialsProvider.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+
+package aws.sdk.kotlin.runtime.auth.credentials
+
+import aws.sdk.kotlin.crt.auth.credentials.build
+import aws.sdk.kotlin.runtime.crt.SdkDefaultIO
+import aws.sdk.kotlin.crt.auth.credentials.EcsCredentialsProvider as EcsCredentialsProviderCrt
+
+/**
+ * A provider that gets credentials from an ECS environment
+ *
+ * @param host The host component of the URL to query credentials from
+ * @param pathAndQuery The path and query components of the URI, concatenated, to query credentials from
+ * @param authToken The token to pass to ECS credential service
+ */
+public class EcsCredentialsProvider public constructor(
+    host: String? = null,
+    pathAndQuery: String? = null,
+    authToken: String? = null,
+) : CrtCredentialsProvider {
+    override val crtProvider: EcsCredentialsProviderCrt = EcsCredentialsProviderCrt.build {
+        clientBootstrap = SdkDefaultIO.ClientBootstrap
+        tlsContext = SdkDefaultIO.TlsContext
+        this.host = host
+        this.pathAndQuery = pathAndQuery
+        this.authToken = authToken
+    }
+}