Add complete secondary support

Respond to notifies and allow a secondary to follow the SOA parameters

to update a zone from a primary. Also sprinkle it with logging.



Also extend monitoring to include qtype in more metrics.

middleware/file/zone.go

@@ -25,6 +25,15 @@ func NewZone(name string) *Zone {
 	return z
 }
 
+// Copy copies a zone *without* copying the zone's content. It is not a deep copy.
+func (z *Zone) Copy() *Zone {
+	z1 := NewZone(z.name)
+	z1.TransferTo = z.TransferTo
+	z1.TransferFrom = z.TransferFrom
+	z1.Expired = z.Expired
+	return z1
+}
+
 // Insert inserts r into z.
 func (z *Zone) Insert(r dns.RR) { z.Tree.Insert(r) }