// Start the app on the configured host/port.
//
// Supports graceful shutdown on 'kill' and 'int' signals.
func (app *App) Run() error {
// toggle heartbeat on SIGUSR1
go func() {
app.heartbeater.Start()
heartbeatChan := make(chan os.Signal, 1)
signal.Notify(heartbeatChan, syscall.SIGUSR1)
for s := range heartbeatChan {
log.Infof("Received signal: %v, toggling heartbeat", s)
app.heartbeater.Toggle()
}
}()
// listen for a shutdown signal
go func() {
exitChan := make(chan os.Signal, 1)
signal.Notify(exitChan, syscall.SIGINT, syscall.SIGQUIT, syscall.SIGTERM)
s := <-exitChan
log.Infof("Got shutdown signal: %v", s)
manners.Close()
}()
addr := fmt.Sprintf("%v:%v", app.Config.ListenIP, app.Config.ListenPort)
return manners.ListenAndServe(addr, app.router)
}
// supervise() listens for error notifications and triggers graceful restart
func (s *Supervisor) supervise() {
for {
select {
case err := <-s.restartC:
// This means graceful shutdown, do nothing and return
if err == nil {
log.Infof("watchErrors - graceful shutdown")
s.stop()
return
}
for {
s.options.Clock.Sleep(retryPeriod)
log.Infof("supervise() restarting %s on error: %s", s.proxy, err)
// We failed to initialize server, this error can not be recovered, so send an error and exit
if err := s.init(); err != nil {
log.Infof("Failed to initialize %s, will retry", err)
} else {
break
}
}
case <-s.broadcastCloseC:
s.Stop(false)
}
}
}
func (m *mux) TakeFiles(files []*FileDescriptor) error {
log.Infof("%s TakeFiles %s", m, files)
fMap := make(map[engine.Address]*FileDescriptor, len(files))
for _, f := range files {
fMap[f.Address] = f
}
m.mtx.Lock()
defer m.mtx.Unlock()
for _, srv := range m.servers {
file, exists := fMap[srv.listener.Address]
if !exists {
log.Infof("%s skipping take of files from address %s, has no passed files", m, srv.listener.Address)
continue
}
if err := srv.takeFile(file); err != nil {
return err
}
}
return nil
}
// Subscribe watches etcd changes and generates structured events telling vulcand to add or delete frontends, hosts etc.
// It is a blocking function.
func (n *ng) Subscribe(changes chan interface{}, cancelC chan bool) error {
// This index helps us to get changes in sequence, as they were performed by clients.
waitIndex := uint64(0)
for {
response, err := n.client.Watch(n.etcdKey, waitIndex, true, nil, cancelC)
if err != nil {
switch err {
case etcd.ErrWatchStoppedByUser:
log.Infof("Stop watching: graceful shutdown")
return nil
default:
log.Errorf("unexpected error: %s, stop watching", err)
return err
}
}
waitIndex = response.Node.ModifiedIndex + 1
log.Infof("%s", responseToString(response))
change, err := n.parseChange(response)
if err != nil {
log.Warningf("Ignore '%s', error: %s", responseToString(response), err)
continue
}
if change != nil {
log.Infof("%v", change)
select {
case changes <- change:
case <-cancelC:
return nil
}
}
}
}
func (s *srv) serve(srv *manners.GracefulServer) {
log.Infof("%s serve", s)
s.mux.wg.Add(1)
defer s.mux.wg.Done()
srv.ListenAndServe()
log.Infof("%v stop", s)
}
func (s *Supervisor) stop() {
srv := s.getCurrentProxy()
if srv != nil {
srv.Stop(true)
log.Infof("%s was stopped by supervisor", srv)
}
log.Infof("Wait for any outstanding operations to complete")
s.wg.Wait()
log.Infof("All outstanding operations have been completed, signalling stop")
close(s.closeC)
}
func (s *Service) startChild() error {
log.Infof("Starting child")
path, err := execPath()
if err != nil {
return err
}
wd, err := os.Getwd()
if nil != err {
return err
}
// Get socket files currently in use by the underlying http server controlled by supervisor
extraFiles, err := s.supervisor.GetFiles()
if err != nil {
return err
}
apiFile, err := s.GetAPIFile()
if err != nil {
return err
}
extraFiles = append(extraFiles, apiFile)
// These files will be passed to the child process
files := []*os.File{os.Stdin, os.Stdout, os.Stderr}
for _, f := range extraFiles {
files = append(files, f.File)
}
// Serialize files to JSON string representation
vals, err := filesToString(extraFiles)
if err != nil {
return err
}
log.Infof("Passing %s to child", vals)
os.Setenv(vulcandFilesKey, vals)
p, err := os.StartProcess(path, os.Args, &os.ProcAttr{
Dir: wd,
Env: os.Environ(),
Files: files,
Sys: &syscall.SysProcAttr{},
})
if err != nil {
return err
}
log.Infof("Started new child pid=%d binary=%s", p.Pid, path)
return nil
}
func (m *mux) Stop(wait bool) {
log.Infof("%s Stop(%t)", m, wait)
m.stopServers()
if wait {
log.Infof("%s waiting for the wait group to finish", m)
m.wg.Wait()
log.Infof("%s wait group finished", m)
}
}
func (r *ratioController) allowRequest() bool {
log.Infof("%v", r)
t := r.targetRatio()
// This condition answers the question - would we satisfy the target ratio if we allow this request?
e := r.computeRatio(r.allowed+1, r.denied)
if e < t {
r.allowed++
log.Infof("%v allowed", r)
return true
}
r.denied++
log.Infof("%v denied", r)
return false
}
func (m *mux) upsertListener(l engine.Listener) error {
lk := engine.ListenerKey{Id: l.Id}
s, exists := m.servers[lk]
if exists {
return s.updateListener(l)
}
// Check if there's a listener with the same address
for _, srv := range m.servers {
if srv.listener.Address == l.Address {
return &engine.AlreadyExistsError{Message: fmt.Sprintf("%v conflicts with existing %v", l, srv.listener)}
}
}
var err error
if s, err = newSrv(m, l); err != nil {
return err
}
m.servers[lk] = s
// If we are active, start the server immediatelly
if m.state == stateActive {
log.Infof("Mux is in active state, starting the HTTP server")
if err := s.start(); err != nil {
return err
}
}
return nil
}
func (m *mux) UpsertListener(l engine.Listener) error {
log.Infof("%v UpsertListener %v", m, &l)
m.mtx.Lock()
defer m.mtx.Unlock()
return m.upsertListener(l)
}
func (m *mux) DeleteHost(hk engine.HostKey) error {
log.Infof("%s DeleteHost %v", m, &hk)
m.mtx.Lock()
defer m.mtx.Unlock()
host, exists := m.hosts[hk]
if !exists {
return &engine.NotFoundError{Message: fmt.Sprintf("%v not found", hk)}
}
// delete host from the hosts list
delete(m.hosts, hk)
// delete staple from the cache
m.stapler.DeleteHost(hk)
if host.Settings.KeyPair == nil {
return nil
}
for _, s := range m.servers {
s.reload()
}
return nil
}
func (s *srv) takeFile(f *FileDescriptor) error {
log.Infof("%s takeFile %v", s, f)
listener, err := f.ToListener()
if err != nil {
return err
}
if s.isTLS() {
tcpListener, ok := listener.(*net.TCPListener)
if !ok {
return fmt.Errorf(`%s failed to take file descriptor - it is running in TLS mode so I need a TCP listener,
but the file descriptor that was given corresponded to a listener of type %T. More about file descriptor: %s`, listener, s, f)
}
config, err := s.newTLSConfig()
if err != nil {
return err
}
listener = manners.NewTLSListener(
manners.TCPKeepAliveListener{tcpListener}, config)
}
s.srv = manners.NewWithOptions(
manners.Options{
Server: s.newHTTPServer(),
Listener: listener,
StateHandler: s.mux.connTracker.onStateChange,
})
s.state = srvStateHijacked
return nil
}
// Make a handler out of HandlerWithBodyFunc, just like regular MakeHandler function.
func MakeHandlerWithBody(app *App, fn HandlerWithBodyFunc, spec Spec) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
if err := parseForm(r); err != nil {
ReplyInternalError(w, fmt.Sprintf("Failed to parse request form: %v", err))
return
}
body, err := ioutil.ReadAll(r.Body)
if err != nil {
ReplyInternalError(w, fmt.Sprintf("Failed to read request body: %v", err))
return
}
start := time.Now()
response, err := fn(w, r, mux.Vars(r), body)
elapsedTime := time.Since(start)
var status int
if err != nil {
response, status = responseAndStatusFor(err)
} else {
status = http.StatusOK
}
log.Infof("Request(Status=%v, Method=%v, Path=%v, Form=%v, Time=%v, Error=%v)",
status, r.Method, r.URL, r.Form, elapsedTime, err)
app.stats.TrackRequest(spec.MetricName, status, elapsedTime)
Reply(w, response, status)
}
}
func (c *ProxyController) deleteFrontend(w http.ResponseWriter, r *http.Request, params map[string]string) (interface{}, error) {
log.Infof("Delete Frontend(id=%s)", params["id"])
if err := c.ng.DeleteFrontend(engine.FrontendKey{Id: params["id"]}); err != nil {
return nil, formatError(err)
}
return scroll.Response{"message": "Frontend deleted"}, nil
}
func (s *srv) start() error {
log.Infof("%s start", s)
switch s.state {
case srvStateInit:
listener, err := net.Listen(s.listener.Address.Network, s.listener.Address.Address)
if err != nil {
return err
}
if s.isTLS() {
config, err := s.newTLSConfig()
if err != nil {
return err
}
listener = manners.NewTLSListener(
manners.TCPKeepAliveListener{listener.(*net.TCPListener)}, config)
}
s.srv = manners.NewWithOptions(
manners.Options{
Server: s.newHTTPServer(),
Listener: listener,
StateHandler: s.mux.connTracker.onStateChange,
})
s.state = srvStateActive
go s.serve(s.srv)
return nil
case srvStateHijacked:
s.state = srvStateActive
go s.serve(s.srv)
return nil
}
return fmt.Errorf("%v Calling start in unsupported state", s)
}
// TODO: implement rollback in case of suboperation failure
func (f *frontend) update(ef engine.Frontend, b *backend) error {
oldf := f.frontend
f.frontend = ef
if err := f.updateBackend(b); err != nil {
return err
}
if oldf.Route != ef.Route {
log.Infof("%v updating route from %v to %v", oldf.Route, ef.Route)
if err := f.mux.router.Handle(ef.Route, f.handler); err != nil {
return err
}
if err := f.mux.router.Remove(oldf.Route); err != nil {
return err
}
}
olds := oldf.HTTPSettings()
news := ef.HTTPSettings()
if !olds.Equals(news) {
if err := f.rebuild(); err != nil {
return err
}
}
return nil
}
// RegisterApp adds a new backend and a single server with Vulcand.
func (s *LeaderRegistry) RegisterApp(registration *AppRegistration) error {
log.Infof("Registering app: %v", registration)
endpoint, err := vulcan.NewEndpointWithID(s.Group, registration.Name, registration.Host, registration.Port)
if err != nil {
return err
}
err = s.client.RegisterBackend(endpoint)
if err != nil {
log.Errorf("Failed to register backend for endpoint: %v, %s", endpoint, err)
return err
}
if s.IsMaster {
err = s.maintainLeader(endpoint)
} else {
err = s.initLeader(endpoint)
}
if err != nil {
log.Errorf("Failed to register server for endpoint: %v, %s", endpoint, err)
return err
}
return nil
}
func (c *ProxyController) upsertListener(w http.ResponseWriter, r *http.Request, params map[string]string, body []byte) (interface{}, error) {
listener, err := parseListenerPack(body)
if err != nil {
return nil, formatError(err)
}
log.Infof("Upsert %s", listener)
return formatResult(listener, c.ng.UpsertListener(*listener))
}
func (m *mux) DeleteFrontend(fk engine.FrontendKey) error {
log.Infof("%v DeleteFrontend %v", m, &fk)
m.mtx.Lock()
defer m.mtx.Unlock()
return m.deleteFrontend(fk)
}
func (m *mux) ServerStats(key engine.ServerKey) (*engine.RoundTripStats, error) {
log.Infof("%s ServerStats", m)
m.mtx.Lock()
defer m.mtx.Unlock()
return m.serverStats(key)
}
func (c *ProxyController) deleteServer(w http.ResponseWriter, r *http.Request, params map[string]string) (interface{}, error) {
sk := engine.ServerKey{BackendKey: engine.BackendKey{Id: params["backendId"]}, Id: params["id"]}
log.Infof("Delete %v", sk)
if err := c.ng.DeleteServer(sk); err != nil {
return nil, formatError(err)
}
return scroll.Response{"message": "Server deleted"}, nil
}
func (c *ProxyController) upsertFrontend(w http.ResponseWriter, r *http.Request, params map[string]string, body []byte) (interface{}, error) {
frontend, ttl, err := parseFrontendPack(c.ng.GetRegistry().GetRouter(), body)
if err != nil {
return nil, formatError(err)
}
log.Infof("Upsert %s", frontend)
return formatResult(frontend, c.ng.UpsertFrontend(*frontend, ttl))
}
func (m *mux) UpsertMiddleware(fk engine.FrontendKey, mi engine.Middleware) error {
log.Infof("%v UpsertMiddleware %v, %v", m, &fk, &mi)
m.mtx.Lock()
defer m.mtx.Unlock()
return m.upsertMiddleware(fk, mi)
}
func (m *mux) BackendStats(key engine.BackendKey) (*engine.RoundTripStats, error) {
log.Infof("%s BackendStats", m)
m.mtx.Lock()
defer m.mtx.Unlock()
return m.backendStats(key)
}
// TopFrontends returns locations sorted by criteria (faulty, slow, most used)
// if hostname or backendId is present, will filter out locations for that host or backendId
func (m *mux) TopFrontends(key *engine.BackendKey) ([]engine.Frontend, error) {
log.Infof("%s TopFrontends", m)
m.mtx.Lock()
defer m.mtx.Unlock()
return m.topFrontends(key)
}
func (c *ProxyController) deleteHost(w http.ResponseWriter, r *http.Request, params map[string]string) (interface{}, error) {
hostname := params["hostname"]
log.Infof("Delete host: %s", hostname)
if err := c.ng.DeleteHost(engine.HostKey{Name: hostname}); err != nil {
return nil, formatError(err)
}
return scroll.Response{"message": fmt.Sprintf("Host '%s' deleted", hostname)}, nil
}
func (c *ProxyController) upsertBackend(w http.ResponseWriter, r *http.Request, params map[string]string, body []byte) (interface{}, error) {
b, err := parseBackendPack(body)
if err != nil {
return nil, formatError(err)
}
log.Infof("Upsert Backend: %s", b)
return formatResult(b, c.ng.UpsertBackend(*b))
}
func (c *ProxyController) upsertHost(w http.ResponseWriter, r *http.Request, params map[string]string, body []byte) (interface{}, error) {
host, err := parseHostPack(body)
if err != nil {
return nil, formatError(err)
}
log.Infof("Upsert %s", host)
return formatResult(host, c.ng.UpsertHost(*host))
}
// TopServers returns endpoints sorted by criteria (faulty, slow, mos used)
// if backendId is not empty, will filter out endpoints for that backendId
func (m *mux) TopServers(key *engine.BackendKey) ([]engine.Server, error) {
log.Infof("%s TopServers", m)
m.mtx.Lock()
defer m.mtx.Unlock()
return m.topServers(key)
}