Updating filepath in auto plugin if existing zone's file changes location (#1901) (#1910)

Exporting Zone.File to avoid getters and setters

Updating getter and setter for Zone.File to be less racy

Renaming GetFile to File in zone plugin

plugin/file/reload.go

@@ -22,14 +22,15 @@ func (z *Zone) Reload() error {
 			select {
 
 			case <-tick.C:
-				reader, err := os.Open(z.file)
+				zFile := z.File()
+				reader, err := os.Open(zFile)
 				if err != nil {
-					log.Errorf("Failed to open zone %q in %q: %v", z.origin, z.file, err)
+					log.Errorf("Failed to open zone %q in %q: %v", z.origin, zFile, err)
 					continue
 				}
 
 				serial := z.SOASerialIfDefined()
-				zone, err := Parse(reader, z.origin, z.file, serial)
+				zone, err := Parse(reader, z.origin, zFile, serial)
 				if err != nil {
 					if _, ok := err.(*serialErr); !ok {
 						log.Errorf("Parsing zone %q: %v", z.origin, err)
@@ -43,7 +44,7 @@ func (z *Zone) Reload() error {
 				z.Tree = zone.Tree
 				z.reloadMu.Unlock()
 
-				log.Infof("Successfully reloaded zone %q in %q with serial %d", z.origin, z.file, z.Apex.SOA.Serial)
+				log.Infof("Successfully reloaded zone %q in %q with serial %d", z.origin, zFile, z.Apex.SOA.Serial)
 				z.Notify()
 
 			case <-z.reloadShutdown:

plugin/file/zone.go

@@ -124,6 +124,20 @@ func (z *Zone) Insert(r dns.RR) error {
 // Delete deletes r from z.
 func (z *Zone) Delete(r dns.RR) { z.Tree.Delete(r) }
 
+// File retrieves the file path in a safe way
+func (z *Zone) File() string {
+	z.reloadMu.Lock()
+	defer z.reloadMu.Unlock()
+	return z.file
+}
+
+// SetFile updates the file path in a safe way
+func (z *Zone) SetFile(path string) {
+	z.reloadMu.Lock()
+	z.file = path
+	z.reloadMu.Unlock()
+}
+
 // TransferAllowed checks if incoming request for transferring the zone is allowed according to the ACLs.
 func (z *Zone) TransferAllowed(state request.Request) bool {
 	for _, t := range z.TransferTo {