feat: emit additional tracing logs from ImdsClient

Author: ianbotsf

.changes/08b59d71-d7b8-4931-806f-105fd005c30e.json

@@ -0,0 +1,5 @@
+{
+    "id": "08b59d71-d7b8-4931-806f-105fd005c30e",
+    "type": "feature",
+    "description": "Emit additional tracing logs from the IMDS client"
+}

aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/config/imds/ImdsClient.kt

@@ -24,6 +24,7 @@ import aws.smithy.kotlin.runtime.io.Closeable
 import aws.smithy.kotlin.runtime.io.closeIfCloseable
 import aws.smithy.kotlin.runtime.io.middleware.Phase
 import aws.smithy.kotlin.runtime.operation.ExecutionContext
+import aws.smithy.kotlin.runtime.telemetry.logging.logger
 import aws.smithy.kotlin.runtime.time.Clock
 import aws.smithy.kotlin.runtime.util.PlatformProvider
 import kotlin.coroutines.coroutineContext
@@ -111,11 +112,13 @@ public class ImdsClient private constructor(builder: Builder) : InstanceMetadata
      * ```
      */
     public override suspend fun get(path: String): String {
+        val logger = coroutineContext.logger<ImdsClient>()
         val op = SdkHttpOperation.build<Unit, String> {
             serializeWith = HttpSerializer.Unit
             deserializeWith = object : HttpDeserializer.NonStreaming<String> {
                 override fun deserialize(context: ExecutionContext, call: HttpCall, payload: ByteArray?): String {
                     val response = call.response
+                    logger.trace { call.toTraceString() }
                     if (response.status.isSuccess()) {
                         return payload!!.decodeToString()
                     } else {
@@ -240,3 +243,17 @@ public class EC2MetadataError(public val status: HttpStatusCode, message: String
     @Deprecated("This property is now deprecated and should be fetched from status.value. This declaration will be removed in version 1.6.x.")
     public val statusCode: Int = status.value
 }
+
+/**
+ * Formats an executed [HttpCall] into a form suitable for TRACE logging. Example output:
+ *
+ * `HTTP GET http://169.254.169.254/latest/meta-data/iam/security-credentials/ --> 200 OK`
+ */
+internal fun HttpCall.toTraceString() = listOf(
+    "HTTP",
+    request.method,
+    request.url,
+    "-->",
+    response.status.value,
+    response.status.description,
+).joinToString(" ")

aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/config/imds/TokenMiddleware.kt

@@ -6,13 +6,12 @@
 package aws.sdk.kotlin.runtime.config.imds
 
 import aws.smithy.kotlin.runtime.http.*
-import aws.smithy.kotlin.runtime.http.complete
 import aws.smithy.kotlin.runtime.http.operation.ModifyRequestMiddleware
 import aws.smithy.kotlin.runtime.http.operation.SdkHttpOperation
 import aws.smithy.kotlin.runtime.http.operation.SdkHttpRequest
 import aws.smithy.kotlin.runtime.http.operation.setResolvedEndpoint
 import aws.smithy.kotlin.runtime.http.request.HttpRequestBuilder
-import aws.smithy.kotlin.runtime.telemetry.logging.trace
+import aws.smithy.kotlin.runtime.telemetry.logging.logger
 import aws.smithy.kotlin.runtime.time.Clock
 import aws.smithy.kotlin.runtime.util.CachedValue
 import aws.smithy.kotlin.runtime.util.ExpiringValue
@@ -49,7 +48,8 @@ internal class TokenMiddleware(
     }
 
     private suspend fun getToken(clock: Clock, req: SdkHttpRequest): Token {
-        coroutineContext.trace<TokenMiddleware> { "refreshing IMDS token" }
+        val logger = coroutineContext.logger<TokenMiddleware>()
+        logger.trace { "refreshing IMDS token" }
 
         val tokenReq = HttpRequestBuilder().apply {
             method = HttpMethod.PUT
@@ -63,6 +63,7 @@ internal class TokenMiddleware(
         setResolvedEndpoint(SdkHttpRequest(tokenReq), endpoint)
 
         val call = httpClient.call(tokenReq)
+        logger.trace { call.toTraceString() }
         return try {
             when (call.response.status) {
                 HttpStatusCode.OK -> {