func (srv *DNSServer) ListenAndServe() error {
if srv.GetStore() == nil {
panic("missing Store")
}
if srv.Domain == "" {
srv.Domain = dnsDomain
}
if err := srv.validateRecursors(); err != nil {
return err
}
api := dnsAPI{srv}
mux := dns.NewServeMux()
mux.HandleFunc(srv.Domain, api.ServiceLookup)
if len(srv.Recursors) > 0 {
mux.HandleFunc(".", api.Recurse)
}
errors := make(chan error, 4)
done := func() { errors <- nil }
if srv.UDPAddr != "" {
l, err := reuseport.NewReusablePortPacketConn("udp4", srv.UDPAddr)
if err != nil {
return err
}
srv.UDPAddr = l.(*net.UDPConn).LocalAddr().String()
server := &dns.Server{
Net: "udp",
PacketConn: l,
Handler: mux,
NotifyStartedFunc: done,
}
go func() { errors <- server.ActivateAndServe() }()
srv.servers = append(srv.servers, server)
}
if srv.TCPAddr != "" {
l, err := keepalive.ReusableListen("tcp4", srv.TCPAddr)
if err != nil {
return err
}
srv.TCPAddr = l.Addr().String()
server := &dns.Server{
Net: "tcp",
Listener: l,
Handler: mux,
NotifyStartedFunc: done,
}
go func() { errors <- server.ActivateAndServe() }()
srv.servers = append(srv.servers, server)
}
for range srv.servers {
if err := <-errors; err != nil {
return err
}
}
return nil
}
// Ensure the store can be restored from a snapshot
func TestStore_RestoreSnapshot(t *testing.T) {
// open a store, add some services and trigger a snapshot
s := MustOpenStore()
serviceNames := []string{"service0", "service1"}
for _, name := range serviceNames {
if err := s.AddService(name, nil); err != nil {
s.Close()
t.Fatal(err)
}
}
if err := s.TriggerSnapshot(); err != nil {
s.Close()
t.Fatal(err)
}
s.Store.Close()
// open another store with same path and port which will attempt
// to restore the snapshot
_, port, _ := net.SplitHostPort(s.Listener.Addr().String())
ln, err := keepalive.ReusableListen("tcp4", "127.0.0.1:"+port)
if err != nil {
t.Fatal(err)
}
s = NewStoreWithConfig(StoreConfig{Path: s.Path(), Listener: ln})
defer s.Close()
if err := s.Open(); err != nil {
t.Fatal(err)
}
// check the data was restored
if !reflect.DeepEqual(s.ServiceNames(), serviceNames) {
t.Fatalf("expected service names %v, got %v", serviceNames, s.ServiceNames())
}
}
func NewStoreWithConfig(config StoreConfig) *Store {
if config.Path == "" {
// Generate a temporary path.
f, _ := ioutil.TempFile("", "discoverd-store-")
f.Close()
os.Remove(f.Name())
config.Path = f.Name()
}
// Initialize store.
s := &Store{Store: server.NewStore(config.Path)}
if config.Listener == nil {
// Open listener on random port.
ln, err := keepalive.ReusableListen("tcp4", "127.0.0.1:0")
if err != nil {
panic(err)
}
config.Listener = ln
}
_, port, _ := net.SplitHostPort(config.Listener.Addr().String())
// Set default test settings.
s.Listener = config.Listener
s.Advertise, _ = net.ResolveTCPAddr("tcp", net.JoinHostPort("localhost", port))
s.HeartbeatTimeout = 50 * time.Millisecond
s.ElectionTimeout = 50 * time.Millisecond
s.LeaderLeaseTimeout = 50 * time.Millisecond
s.CommitTimeout = 5 * time.Millisecond
s.EnableSingleNode = true
// Turn off logs if verbose flag is not set.
if !testing.Verbose() {
s.LogOutput = ioutil.Discard
}
return s
}