Querylog -- Omit empty fields when writing json

coredns_plugin/querylog.go

@@ -30,7 +30,7 @@ var (
 
 type logEntry struct {
 	Question []byte
-	Answer   []byte
+	Answer   []byte `json:",omitempty"` // sometimes empty answers happen like binerdunt.top or rev2.globalrootservers.net
 	Result   dnsfilter.Result
 	Time     time.Time
 	Elapsed  time.Duration

dnsfilter/dnsfilter.go

@@ -136,9 +136,9 @@ var (
 
 // Result holds state of hostname check
 type Result struct {
-	IsFiltered bool
-	Reason     Reason
-	Rule       string
+	IsFiltered bool   `json:",omitempty"`
+	Reason     Reason `json:",omitempty"`
+	Rule       string `json:",omitempty"`
 }
 
 // Matched can be used to see if any match at all was found, no matter filtered or not