Improve MSDNS naptr support (#1165)

* MSDNS: Improve reliability of zone dump

* Update tests

* MSDNS: Add initial NAPTR support

* Update

* fix tests

* fix tests

* Fixing integration tests for NAPTR

* Handle bad JSON. Handle NAPTR TTLs

models/t_naptr.go

@@ -8,6 +8,9 @@ import (
 
 // SetTargetNAPTR sets the NAPTR fields.
 func (rc *RecordConfig) SetTargetNAPTR(order uint16, preference uint16, flags string, service string, regexp string, target string) error {
+	if target == "" {
+		target = "."
+	}
 	rc.NaptrOrder = order
 	rc.NaptrPreference = preference
 	rc.NaptrFlags = flags

models/target.go

@@ -55,14 +55,16 @@ func (rc *RecordConfig) GetTargetCombined() string {
 		case "AZURE_ALIAS":
 			// Differentiate between multiple AZURE_ALIASs on the same label.
 			return fmt.Sprintf("%s atype=%s", rc.target, rc.AzureAlias["type"])
-		case "SOA":
-			return fmt.Sprintf("%s %v %d %d %d %d %d", rc.target, rc.SoaMbox, rc.SoaSerial, rc.SoaRefresh, rc.SoaRetry, rc.SoaExpire, rc.SoaMinttl)
 		default:
 			// Just return the target.
 			return rc.target
 		}
 	}
 
+	if rc.Type == "SOA" {
+		return fmt.Sprintf("%s %v %d %d %d %d %d", rc.target, rc.SoaMbox, rc.SoaSerial, rc.SoaRefresh, rc.SoaRetry, rc.SoaExpire, rc.SoaMinttl)
+	}
+
 	return rc.zoneFileQuoted()
 }
 
@@ -73,6 +75,9 @@ func (rc *RecordConfig) zoneFileQuoted() string {
 	// Sadly String() always includes a header, which we must strip out.
 	// TODO(tlim): Request the dns project add a function that returns
 	// the string without the header.
+	if rc.Type == "NAPTR" && rc.GetTargetField() == "" {
+		rc.SetTarget(".")
+	}
 	rr := rc.ToRR()
 	header := rr.Header().String()
 	full := rr.String()