Restore InstanceNotFound comment & logic

pkg/cloudprovider/cloud.go

@@ -131,6 +131,7 @@ type Instances interface {
 	// services cannot be used in this method to obtain nodeaddresses
 	NodeAddressesByProviderID(ctx context.Context, providerID string) ([]v1.NodeAddress, error)
 	// InstanceID returns the cloud provider ID of the node with the specified NodeName.
+	// Note that if the instance does not exist or is no longer running, we must return ("", cloudprovider.InstanceNotFound)
 	InstanceID(ctx context.Context, nodeName types.NodeName) (string, error)
 	// InstanceType returns the type of the specified instance.
 	InstanceType(ctx context.Context, name types.NodeName) (string, error)

pkg/cloudprovider/providers/aws/aws.go

@@ -1363,6 +1363,10 @@ func (c *Cloud) InstanceID(ctx context.Context, nodeName types.NodeName) (string
 	}
 	inst, err := c.getInstanceByNodeName(nodeName)
 	if err != nil {
+		if err == cloudprovider.InstanceNotFound {
+			// The Instances interface requires that we return InstanceNotFound (without wrapping)
+			return "", err
+		}
 		return "", fmt.Errorf("getInstanceByNodeName failed for %q with %q", nodeName, err)
 	}
 	return "/" + aws.StringValue(inst.Placement.AvailabilityZone) + "/" + aws.StringValue(inst.InstanceId), nil