more config

internal/resolver/resolver_test.go

@@ -656,3 +656,42 @@ func TestHealthCheckProbesEveryUpstream(t *testing.T) {
 		t.Error("the dead upstream was not taken out of rotation")
 	}
 }
+
+func TestForwardZones(t *testing.T) {
+	public := newFakeUpstream(t, fakeOpt{ip: "203.0.113.1"})
+	firewall := newFakeUpstream(t, fakeOpt{ip: "10.10.11.117", truncateUDP: true})
+	specific := newFakeUpstream(t, fakeOpt{ip: "10.10.11.118"})
+	cfg := poolCfg(udpServer(public.addr))
+	cfg.ForwardZones = []config.ForwardZone{
+		{Zone: "local", Servers: []config.UpstreamServer{udpServer(firewall.addr)}},
+		{Zone: "lab.local", Servers: []config.UpstreamServer{udpServer(specific.addr)}},
+	}
+	p := NewPool(cfg)
+	for _, tc := range []struct{ name, addr string }{
+		{"fastpi.LoCaL.", firewall.addr}, {"local.", firewall.addr},
+		{"host.lab.local.", specific.addr}, {"notlocal.", public.addr},
+		{"local.example.", public.addr},
+	} {
+		_, addr, err := p.Exchange(testCtx(t), query(tc.name), []string{public.addr}, time.Second)
+		if err != nil || addr != tc.addr {
+			t.Fatalf("%s: addr=%s err=%v, want %s", tc.name, addr, err, tc.addr)
+		}
+	}
+	if firewall.tcpHits.Load() == 0 {
+		t.Fatal("forwarded truncated UDP answer did not retry TCP")
+	}
+	before := public.udpHits.Load()
+	cfg.ForwardZones[0].Servers = []config.UpstreamServer{udpServer("127.0.0.1:1")}
+	p.Rebind(cfg)
+	if _, _, err := p.Exchange(testCtx(t), query("fastpi.local."), nil, 50*time.Millisecond); err == nil {
+		t.Fatal("dead route succeeded")
+	}
+	if public.udpHits.Load() != before {
+		t.Fatal("private query leaked to public upstream")
+	}
+	cfg.ForwardZones = nil
+	p.Rebind(cfg)
+	if _, addr, err := p.Exchange(testCtx(t), query("fastpi.local."), nil, time.Second); err != nil || addr != public.addr {
+		t.Fatalf("removed route: %s %v", addr, err)
+	}
+}