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/auto/watcher_test.go

@@ -51,4 +51,51 @@ func TestWatcher(t *testing.T) {
 	if _, ok := a.Zones.Z["example.org."]; !ok {
 		t.Errorf("Expected %q to still be there.", "example.org.")
 	}
+
+}
+
+func TestSymlinks(t *testing.T) {
+	tempdir, err := createFiles()
+	if err != nil {
+		if tempdir != "" {
+			os.RemoveAll(tempdir)
+		}
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tempdir)
+
+	ldr := loader{
+		directory: tempdir,
+		re:        regexp.MustCompile(`db\.(.*)`),
+		template:  `${1}`,
+	}
+
+	a := Auto{
+		loader: ldr,
+		Zones:  &Zones{},
+	}
+
+	a.Walk()
+
+	// Now create a duplicate file in a subdirectory and repoint the symlink
+	if err := os.Remove(path.Join(tempdir, "db.example.com")); err != nil {
+		t.Fatal(err)
+	}
+	dataDir := path.Join(tempdir, "..data")
+	if err = os.Mkdir(dataDir, 0755); err != nil {
+		t.Fatal(err)
+	}
+	newFile := path.Join(dataDir, "db.example.com")
+	if err = os.Symlink(path.Join(tempdir, "db.example.org"), newFile); err != nil {
+		t.Fatal(err)
+	}
+
+	a.Walk()
+
+	if storedZone, ok := a.Zones.Z["example.com."]; ok {
+		storedFile := storedZone.File()
+		if storedFile != newFile {
+			t.Errorf("Expected %q to reflect new path %q", storedFile, newFile)
+		}
+	}
 }