plugin/file: trigger reload of zones based on mtime (#8085)

* Added fs.FileInfo.ModTime() based reload feature Signed-off-by: Endre Szabo <git@end.re> * Updated the plugin documentation. Signed-off-by: Endre Szabo <git@end.re> --------- Signed-off-by: Endre Szabo <git@end.re>
2026-05-26 11:50:24 -04:00 · 2026-05-20 04:43:46 +02:00
parent ee7ff82cf5
commit 35391dd8a9
6 changed files with 283 additions and 4 deletions
--- a/plugin/file/reload_test.go
+++ b/plugin/file/reload_test.go
@@ -77,6 +77,253 @@ func TestZoneReloadSOAChange(t *testing.T) {
 	}
 }

+func TestZoneReloadByMtime(t *testing.T) {
+	// Test 1: Basic mtime trigger - file modification should trigger reload
+	t.Run("BasicMtimeTrigger", func(t *testing.T) {
+		fileName, rm, err := test.TempFile(".", reloadZoneTest)
+		if err != nil {
+			t.Fatalf("Failed to create zone: %s", err)
+		}
+		defer rm()
+
+		reader, err := os.Open(fileName)
+		if err != nil {
+			t.Fatalf("Failed to open zone: %s", err)
+		}
+		z, err := Parse(reader, "miek.nl", fileName, 0)
+		if err != nil {
+			t.Fatalf("Failed to parse zone: %s", err)
+		}
+		reader.Close()
+
+		// Enable mtime-based reload
+		z.ReloadInterval = 10 * time.Millisecond
+		z.ReloadByMtime = true
+		z.Reload(&transfer.Transfer{})
+
+		// Wait for initial load to complete
+		time.Sleep(20 * time.Millisecond)
+
+		// Verify initial content (5 records)
+		rrs, err := z.ApexIfDefined()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(rrs) != 5 {
+			t.Fatalf("Expected 5 initial RRs, got %d", len(rrs))
+		}
+
+		// Modify the zone file (this changes mtime)
+		if err := os.WriteFile(fileName, []byte(reloadZone2Test), 0644); err != nil {
+			t.Fatalf("Failed to write new zone data: %s", err)
+		}
+
+		// Wait for reload to trigger
+		time.Sleep(30 * time.Millisecond)
+
+		// Verify reload occurred (3 records now)
+		rrs, err = z.ApexIfDefined()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(rrs) != 3 {
+			t.Fatalf("Expected 3 RRs after reload, got %d", len(rrs))
+		}
+	})
+
+	// Test 2: No reload when mtime unchanged
+	t.Run("NoReloadWhenMtimeUnchanged", func(t *testing.T) {
+		fileName, rm, err := test.TempFile(".", reloadZoneTest)
+		if err != nil {
+			t.Fatalf("Failed to create zone: %s", err)
+		}
+		defer rm()
+
+		reader, err := os.Open(fileName)
+		if err != nil {
+			t.Fatalf("Failed to open zone: %s", err)
+		}
+		z, err := Parse(reader, "miek.nl", fileName, 0)
+		if err != nil {
+			t.Fatalf("Failed to parse zone: %s", err)
+		}
+		reader.Close()
+
+		// Enable mtime-based reload
+		z.ReloadInterval = 10 * time.Millisecond
+		z.ReloadByMtime = true
+		z.Reload(&transfer.Transfer{})
+
+		// Wait for initial load
+		time.Sleep(20 * time.Millisecond)
+
+		// Record initial SOA serial
+		initialSerial := z.SOASerialIfDefined()
+		if initialSerial == -1 {
+			t.Fatal("Failed to get initial SOA serial")
+		}
+
+		// Record initial record count
+		rrs, err := z.ApexIfDefined()
+		if err != nil {
+			t.Fatal(err)
+		}
+		initialCount := len(rrs)
+
+		// Wait for multiple reload intervals WITHOUT modifying the file
+		time.Sleep(50 * time.Millisecond)
+
+		// Verify no reload occurred
+		currentSerial := z.SOASerialIfDefined()
+		if currentSerial != initialSerial {
+			t.Fatalf("SOA serial changed unexpectedly: %d -> %d", initialSerial, currentSerial)
+		}
+
+		rrs, err = z.ApexIfDefined()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(rrs) != initialCount {
+			t.Fatalf("Record count changed unexpectedly: %d -> %d", initialCount, len(rrs))
+		}
+	})
+
+	// Test 3: Content verification after reload
+	t.Run("ContentVerificationAfterReload", func(t *testing.T) {
+		fileName, rm, err := test.TempFile(".", reloadZoneTest)
+		if err != nil {
+			t.Fatalf("Failed to create zone: %s", err)
+		}
+		defer rm()
+
+		reader, err := os.Open(fileName)
+		if err != nil {
+			t.Fatalf("Failed to open zone: %s", err)
+		}
+		z, err := Parse(reader, "miek.nl", fileName, 0)
+		if err != nil {
+			t.Fatalf("Failed to parse zone: %s", err)
+		}
+		reader.Close()
+
+		// Enable mtime-based reload
+		z.ReloadInterval = 10 * time.Millisecond
+		z.ReloadByMtime = true
+		z.Reload(&transfer.Transfer{})
+
+		ctx := context.TODO()
+
+		// Query initial content
+		r := new(dns.Msg)
+		r.SetQuestion("miek.nl", dns.TypeNS)
+		state := request.Request{W: &test.ResponseWriter{}, Req: r}
+
+		records, _, _, res := z.Lookup(ctx, state, "miek.nl.")
+		if res != Success {
+			t.Fatalf("Failed to lookup initial NS records, got %d", res)
+		}
+
+		// Initial zone has 4 NS records
+		if len(records) != 4 {
+			t.Fatalf("Expected 4 initial NS records, got %d", len(records))
+		}
+
+		// Modify to new zone content (only 2 NS records)
+		if err := os.WriteFile(fileName, []byte(reloadZone2Test), 0644); err != nil {
+			t.Fatalf("Failed to write new zone data: %s", err)
+		}
+
+		// Wait for reload
+		time.Sleep(30 * time.Millisecond)
+
+		// Query new content
+		records, _, _, res = z.Lookup(ctx, state, "miek.nl.")
+		if res != Success {
+			t.Fatalf("Failed to lookup reloaded NS records, got %d", res)
+		}
+
+		// Reloaded zone has 2 NS records
+		if len(records) != 2 {
+			t.Fatalf("Expected 2 reloaded NS records, got %d", len(records))
+		}
+
+		// Verify the actual NS record names match the new zone
+		nsNames := make([]string, len(records))
+		for i, rr := range records {
+			nsNames[i] = rr.(*dns.NS).Ns
+		}
+
+		expectedNS := []string{"ext.ns.whyscream.net.", "omval.tednet.nl."}
+		for i, expected := range expectedNS {
+			if nsNames[i] != expected {
+				t.Errorf("Expected NS record %d to be %s, got %s", i, expected, nsNames[i])
+			}
+		}
+	})
+
+	// Test 4: File deleted/missing during reload
+	t.Run("FileMissingDuringReload", func(t *testing.T) {
+		fileName, rm, err := test.TempFile(".", reloadZoneTest)
+		if err != nil {
+			t.Fatalf("Failed to create zone: %s", err)
+		}
+		defer rm()
+
+		reader, err := os.Open(fileName)
+		if err != nil {
+			t.Fatalf("Failed to open zone: %s", err)
+		}
+		z, err := Parse(reader, "miek.nl", fileName, 0)
+		if err != nil {
+			t.Fatalf("Failed to parse zone: %s", err)
+		}
+		reader.Close()
+
+		// Enable mtime-based reload
+		z.ReloadInterval = 10 * time.Millisecond
+		z.ReloadByMtime = true
+		z.Reload(&transfer.Transfer{})
+
+		// Wait for initial load
+		time.Sleep(20 * time.Millisecond)
+
+		// Verify initial content is loaded
+		rrs, err := z.ApexIfDefined()
+		if err != nil {
+			t.Fatal(err)
+		}
+		initialCount := len(rrs)
+
+		// Delete the zone file
+		if err := os.Remove(fileName); err != nil {
+			t.Fatalf("Failed to remove zone file: %s", err)
+		}
+
+		// Wait for reload interval (reload should fail gracefully)
+		time.Sleep(30 * time.Millisecond)
+
+		// Verify zone still serves old content (didn't crash)
+		rrs, err = z.ApexIfDefined()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(rrs) != initialCount {
+			t.Fatalf("Zone content changed unexpectedly after file deletion: %d -> %d", initialCount, len(rrs))
+		}
+
+		// Verify DNS queries still work
+		ctx := context.TODO()
+		r := new(dns.Msg)
+		r.SetQuestion("miek.nl", dns.TypeSOA)
+		state := request.Request{W: &test.ResponseWriter{}, Req: r}
+
+		_, _, _, res := z.Lookup(ctx, state, "miek.nl.")
+		if res != Success {
+			t.Fatalf("Zone should still serve queries after file deletion, got result %d", res)
+		}
+	})
+}
+
 const reloadZoneTest = `miek.nl.		1627	IN	SOA	linode.atoom.net. miek.miek.nl. 1460175181 14400 3600 604800 14400
 miek.nl.		1627	IN	NS	ext.ns.whyscream.net.
 miek.nl.		1627	IN	NS	omval.tednet.nl.