Add retry checker for DNS failure from Ingress

test/spoof/error_checks.go

@@ -21,6 +21,7 @@ package spoof
 import (
 	"errors"
 	"net"
+	"net/http"
 	"strings"
 )
 
@@ -62,3 +63,8 @@ func isConnectionReset(err error) bool {
 func isNoRouteToHostError(err error) bool {
 	return err != nil && strings.Contains(err.Error(), "connect: no route to host")
 }
+
+func isResponseDNSError(resp *Response) bool {
+	// no such host with 502 is sent back from istio-ingressgateway when it fails to resolve domain.
+	return resp.StatusCode == http.StatusBadGateway && strings.Contains(string(resp.Body), "no such host")
+}

test/spoof/spoof.go

@@ -164,7 +164,7 @@ func (sc *SpoofingClient) Do(req *http.Request, errorRetryCheckers ...interface{
 // If no retry checkers are specified `DefaultErrorRetryChecker` will be used.
 func (sc *SpoofingClient) Poll(req *http.Request, inState ResponseChecker, checkers ...interface{}) (*Response, error) {
 	if len(checkers) == 0 {
-		checkers = []interface{}{ErrorRetryChecker(DefaultErrorRetryChecker)}
+		checkers = []interface{}{ErrorRetryChecker(DefaultErrorRetryChecker), ResponseRetryChecker(DefaultResponseRetryChecker)}
 	}
 
 	var resp *Response
@@ -255,6 +255,14 @@ func DefaultErrorRetryChecker(err error) (bool, error) {
 	return false, err
 }
 
+// DefaultResponseRetryChecker implements the defaults for retrying on response.
+func DefaultResponseRetryChecker(resp *Response) (bool, error) {
+	if isResponseDNSError(resp) {
+		return true, fmt.Errorf("retrying for DNS related failure response: %v", resp)
+	}
+	return false, nil
+}
+
 // logZipkinTrace provides support to log Zipkin Trace for param: spoofResponse
 // We only log Zipkin trace for HTTP server errors i.e for HTTP status codes between 500 to 600
 func (sc *SpoofingClient) logZipkinTrace(spoofResp *Response) {