fixed error handling for imds creation

Author: gargipanatula

cmd/aws-iam-authenticator/verify.go

@@ -88,14 +88,14 @@ var verifyCmd = &cobra.Command{
 func getInstanceRegion(ctx context.Context) string {
 	cfg, err := config.LoadDefaultConfig(ctx)
 	if err != nil {
-		fmt.Printf("[Warn] Unable to create metadata client, err: %v", err)
-		return ""
+		fmt.Fprintf(os.Stderr, "[Warn] Unable to create config for metadata client, err: %v", err)
+		panic(err)
 	}
 
 	imdsClient := imds.NewFromConfig(cfg)
 	getRegionOutput, err := imdsClient.GetRegion(ctx, &imds.GetRegionInput{})
 	if err != nil {
-		fmt.Printf("[Warn] Region not found in instance metadata, err: %v\n", err)
+		fmt.Fprintf(os.Stderr, "[Warn] Region not found in instance metadata, err: %v\n", err)
 		return ""
 	}