From 930b639cc9cd2d2873302f30303378c0e53816a8 Mon Sep 17 00:00:00 2001 From: Wim Date: Sat, 18 Feb 2017 23:00:46 +0100 Subject: Update vendor --- vendor/github.com/tylerb/graceful/graceful.go | 489 ++++++++++++++++++++++++++ 1 file changed, 489 insertions(+) create mode 100644 vendor/github.com/tylerb/graceful/graceful.go (limited to 'vendor/github.com/tylerb/graceful/graceful.go') diff --git a/vendor/github.com/tylerb/graceful/graceful.go b/vendor/github.com/tylerb/graceful/graceful.go new file mode 100644 index 00000000..ebf0aeb7 --- /dev/null +++ b/vendor/github.com/tylerb/graceful/graceful.go @@ -0,0 +1,489 @@ +package graceful + +import ( + "crypto/tls" + "log" + "net" + "net/http" + "os" + "sync" + "time" +) + +// Server wraps an http.Server with graceful connection handling. +// It may be used directly in the same way as http.Server, or may +// be constructed with the global functions in this package. +// +// Example: +// srv := &graceful.Server{ +// Timeout: 5 * time.Second, +// Server: &http.Server{Addr: ":1234", Handler: handler}, +// } +// srv.ListenAndServe() +type Server struct { + *http.Server + + // Timeout is the duration to allow outstanding requests to survive + // before forcefully terminating them. + Timeout time.Duration + + // Limit the number of outstanding requests + ListenLimit int + + // TCPKeepAlive sets the TCP keep-alive timeouts on accepted + // connections. It prunes dead TCP connections ( e.g. closing + // laptop mid-download) + TCPKeepAlive time.Duration + + // ConnState specifies an optional callback function that is + // called when a client connection changes state. This is a proxy + // to the underlying http.Server's ConnState, and the original + // must not be set directly. + ConnState func(net.Conn, http.ConnState) + + // BeforeShutdown is an optional callback function that is called + // before the listener is closed. Returns true if shutdown is allowed + BeforeShutdown func() bool + + // ShutdownInitiated is an optional callback function that is called + // when shutdown is initiated. It can be used to notify the client + // side of long lived connections (e.g. websockets) to reconnect. + ShutdownInitiated func() + + // NoSignalHandling prevents graceful from automatically shutting down + // on SIGINT and SIGTERM. If set to true, you must shut down the server + // manually with Stop(). + NoSignalHandling bool + + // Logger used to notify of errors on startup and on stop. + Logger *log.Logger + + // LogFunc can be assigned with a logging function of your choice, allowing + // you to use whatever logging approach you would like + LogFunc func(format string, args ...interface{}) + + // Interrupted is true if the server is handling a SIGINT or SIGTERM + // signal and is thus shutting down. + Interrupted bool + + // interrupt signals the listener to stop serving connections, + // and the server to shut down. + interrupt chan os.Signal + + // stopLock is used to protect against concurrent calls to Stop + stopLock sync.Mutex + + // stopChan is the channel on which callers may block while waiting for + // the server to stop. + stopChan chan struct{} + + // chanLock is used to protect access to the various channel constructors. + chanLock sync.RWMutex + + // connections holds all connections managed by graceful + connections map[net.Conn]struct{} + + // idleConnections holds all idle connections managed by graceful + idleConnections map[net.Conn]struct{} +} + +// Run serves the http.Handler with graceful shutdown enabled. +// +// timeout is the duration to wait until killing active requests and stopping the server. +// If timeout is 0, the server never times out. It waits for all active requests to finish. +func Run(addr string, timeout time.Duration, n http.Handler) { + srv := &Server{ + Timeout: timeout, + TCPKeepAlive: 3 * time.Minute, + Server: &http.Server{Addr: addr, Handler: n}, + // Logger: DefaultLogger(), + } + + if err := srv.ListenAndServe(); err != nil { + if opErr, ok := err.(*net.OpError); !ok || (ok && opErr.Op != "accept") { + srv.logf("%s", err) + os.Exit(1) + } + } + +} + +// RunWithErr is an alternative version of Run function which can return error. +// +// Unlike Run this version will not exit the program if an error is encountered but will +// return it instead. +func RunWithErr(addr string, timeout time.Duration, n http.Handler) error { + srv := &Server{ + Timeout: timeout, + TCPKeepAlive: 3 * time.Minute, + Server: &http.Server{Addr: addr, Handler: n}, + Logger: DefaultLogger(), + } + + return srv.ListenAndServe() +} + +// ListenAndServe is equivalent to http.Server.ListenAndServe with graceful shutdown enabled. +// +// timeout is the duration to wait until killing active requests and stopping the server. +// If timeout is 0, the server never times out. It waits for all active requests to finish. +func ListenAndServe(server *http.Server, timeout time.Duration) error { + srv := &Server{Timeout: timeout, Server: server, Logger: DefaultLogger()} + return srv.ListenAndServe() +} + +// ListenAndServe is equivalent to http.Server.ListenAndServe with graceful shutdown enabled. +func (srv *Server) ListenAndServe() error { + // Create the listener so we can control their lifetime + addr := srv.Addr + if addr == "" { + addr = ":http" + } + conn, err := srv.newTCPListener(addr) + if err != nil { + return err + } + + return srv.Serve(conn) +} + +// ListenAndServeTLS is equivalent to http.Server.ListenAndServeTLS with graceful shutdown enabled. +// +// timeout is the duration to wait until killing active requests and stopping the server. +// If timeout is 0, the server never times out. It waits for all active requests to finish. +func ListenAndServeTLS(server *http.Server, certFile, keyFile string, timeout time.Duration) error { + srv := &Server{Timeout: timeout, Server: server, Logger: DefaultLogger()} + return srv.ListenAndServeTLS(certFile, keyFile) +} + +// ListenTLS is a convenience method that creates an https listener using the +// provided cert and key files. Use this method if you need access to the +// listener object directly. When ready, pass it to the Serve method. +func (srv *Server) ListenTLS(certFile, keyFile string) (net.Listener, error) { + // Create the listener ourselves so we can control its lifetime + addr := srv.Addr + if addr == "" { + addr = ":https" + } + + config := &tls.Config{} + if srv.TLSConfig != nil { + *config = *srv.TLSConfig + } + + var err error + if certFile != "" && keyFile != "" { + config.Certificates = make([]tls.Certificate, 1) + config.Certificates[0], err = tls.LoadX509KeyPair(certFile, keyFile) + if err != nil { + return nil, err + } + } + + // Enable http2 + enableHTTP2ForTLSConfig(config) + + conn, err := srv.newTCPListener(addr) + if err != nil { + return nil, err + } + + srv.TLSConfig = config + + tlsListener := tls.NewListener(conn, config) + return tlsListener, nil +} + +// Enable HTTP2ForTLSConfig explicitly enables http/2 for a TLS Config. This is due to changes in Go 1.7 where +// http servers are no longer automatically configured to enable http/2 if the server's TLSConfig is set. +// See https://github.com/golang/go/issues/15908 +func enableHTTP2ForTLSConfig(t *tls.Config) { + + if TLSConfigHasHTTP2Enabled(t) { + return + } + + t.NextProtos = append(t.NextProtos, "h2") +} + +// TLSConfigHasHTTP2Enabled checks to see if a given TLS Config has http2 enabled. +func TLSConfigHasHTTP2Enabled(t *tls.Config) bool { + for _, value := range t.NextProtos { + if value == "h2" { + return true + } + } + return false +} + +// ListenAndServeTLS is equivalent to http.Server.ListenAndServeTLS with graceful shutdown enabled. +func (srv *Server) ListenAndServeTLS(certFile, keyFile string) error { + l, err := srv.ListenTLS(certFile, keyFile) + if err != nil { + return err + } + + return srv.Serve(l) +} + +// ListenAndServeTLSConfig can be used with an existing TLS config and is equivalent to +// http.Server.ListenAndServeTLS with graceful shutdown enabled, +func (srv *Server) ListenAndServeTLSConfig(config *tls.Config) error { + addr := srv.Addr + if addr == "" { + addr = ":https" + } + + conn, err := srv.newTCPListener(addr) + if err != nil { + return err + } + + srv.TLSConfig = config + + tlsListener := tls.NewListener(conn, config) + return srv.Serve(tlsListener) +} + +// Serve is equivalent to http.Server.Serve with graceful shutdown enabled. +// +// timeout is the duration to wait until killing active requests and stopping the server. +// If timeout is 0, the server never times out. It waits for all active requests to finish. +func Serve(server *http.Server, l net.Listener, timeout time.Duration) error { + srv := &Server{Timeout: timeout, Server: server, Logger: DefaultLogger()} + + return srv.Serve(l) +} + +// Serve is equivalent to http.Server.Serve with graceful shutdown enabled. +func (srv *Server) Serve(listener net.Listener) error { + + if srv.ListenLimit != 0 { + listener = LimitListener(listener, srv.ListenLimit) + } + + // Make our stopchan + srv.StopChan() + + // Track connection state + add := make(chan net.Conn) + idle := make(chan net.Conn) + active := make(chan net.Conn) + remove := make(chan net.Conn) + + srv.Server.ConnState = func(conn net.Conn, state http.ConnState) { + switch state { + case http.StateNew: + add <- conn + case http.StateActive: + active <- conn + case http.StateIdle: + idle <- conn + case http.StateClosed, http.StateHijacked: + remove <- conn + } + + srv.stopLock.Lock() + defer srv.stopLock.Unlock() + + if srv.ConnState != nil { + srv.ConnState(conn, state) + } + } + + // Manage open connections + shutdown := make(chan chan struct{}) + kill := make(chan struct{}) + go srv.manageConnections(add, idle, active, remove, shutdown, kill) + + interrupt := srv.interruptChan() + // Set up the interrupt handler + if !srv.NoSignalHandling { + signalNotify(interrupt) + } + quitting := make(chan struct{}) + go srv.handleInterrupt(interrupt, quitting, listener) + + // Serve with graceful listener. + // Execution blocks here until listener.Close() is called, above. + err := srv.Server.Serve(listener) + if err != nil { + // If the underlying listening is closed, Serve returns an error + // complaining about listening on a closed socket. This is expected, so + // let's ignore the error if we are the ones who explicitly closed the + // socket. + select { + case <-quitting: + err = nil + default: + } + } + + srv.shutdown(shutdown, kill) + + return err +} + +// Stop instructs the type to halt operations and close +// the stop channel when it is finished. +// +// timeout is grace period for which to wait before shutting +// down the server. The timeout value passed here will override the +// timeout given when constructing the server, as this is an explicit +// command to stop the server. +func (srv *Server) Stop(timeout time.Duration) { + srv.stopLock.Lock() + defer srv.stopLock.Unlock() + + srv.Timeout = timeout + sendSignalInt(srv.interruptChan()) +} + +// StopChan gets the stop channel which will block until +// stopping has completed, at which point it is closed. +// Callers should never close the stop channel. +func (srv *Server) StopChan() <-chan struct{} { + srv.chanLock.Lock() + defer srv.chanLock.Unlock() + + if srv.stopChan == nil { + srv.stopChan = make(chan struct{}) + } + return srv.stopChan +} + +// DefaultLogger returns the logger used by Run, RunWithErr, ListenAndServe, ListenAndServeTLS and Serve. +// The logger outputs to STDERR by default. +func DefaultLogger() *log.Logger { + return log.New(os.Stderr, "[graceful] ", 0) +} + +func (srv *Server) manageConnections(add, idle, active, remove chan net.Conn, shutdown chan chan struct{}, kill chan struct{}) { + var done chan struct{} + srv.connections = map[net.Conn]struct{}{} + srv.idleConnections = map[net.Conn]struct{}{} + for { + select { + case conn := <-add: + srv.connections[conn] = struct{}{} + srv.idleConnections[conn] = struct{}{} // Newly-added connections are considered idle until they become active. + case conn := <-idle: + srv.idleConnections[conn] = struct{}{} + case conn := <-active: + delete(srv.idleConnections, conn) + case conn := <-remove: + delete(srv.connections, conn) + delete(srv.idleConnections, conn) + if done != nil && len(srv.connections) == 0 { + done <- struct{}{} + return + } + case done = <-shutdown: + if len(srv.connections) == 0 && len(srv.idleConnections) == 0 { + done <- struct{}{} + return + } + // a shutdown request has been received. if we have open idle + // connections, we must close all of them now. this prevents idle + // connections from holding the server open while waiting for them to + // hit their idle timeout. + for k := range srv.idleConnections { + if err := k.Close(); err != nil { + srv.logf("[ERROR] %s", err) + } + } + case <-kill: + srv.stopLock.Lock() + defer srv.stopLock.Unlock() + + srv.Server.ConnState = nil + for k := range srv.connections { + if err := k.Close(); err != nil { + srv.logf("[ERROR] %s", err) + } + } + return + } + } +} + +func (srv *Server) interruptChan() chan os.Signal { + srv.chanLock.Lock() + defer srv.chanLock.Unlock() + + if srv.interrupt == nil { + srv.interrupt = make(chan os.Signal, 1) + } + + return srv.interrupt +} + +func (srv *Server) handleInterrupt(interrupt chan os.Signal, quitting chan struct{}, listener net.Listener) { + for _ = range interrupt { + if srv.Interrupted { + srv.logf("already shutting down") + continue + } + srv.logf("shutdown initiated") + srv.Interrupted = true + if srv.BeforeShutdown != nil { + if !srv.BeforeShutdown() { + srv.Interrupted = false + continue + } + } + + close(quitting) + srv.SetKeepAlivesEnabled(false) + if err := listener.Close(); err != nil { + srv.logf("[ERROR] %s", err) + } + + if srv.ShutdownInitiated != nil { + srv.ShutdownInitiated() + } + } +} + +func (srv *Server) logf(format string, args ...interface{}) { + if srv.LogFunc != nil { + srv.LogFunc(format, args...) + } else if srv.Logger != nil { + srv.Logger.Printf(format, args...) + } +} + +func (srv *Server) shutdown(shutdown chan chan struct{}, kill chan struct{}) { + // Request done notification + done := make(chan struct{}) + shutdown <- done + + srv.stopLock.Lock() + defer srv.stopLock.Unlock() + if srv.Timeout > 0 { + select { + case <-done: + case <-time.After(srv.Timeout): + close(kill) + } + } else { + <-done + } + // Close the stopChan to wake up any blocked goroutines. + srv.chanLock.Lock() + if srv.stopChan != nil { + close(srv.stopChan) + } + srv.chanLock.Unlock() +} + +func (srv *Server) newTCPListener(addr string) (net.Listener, error) { + conn, err := net.Listen("tcp", addr) + if err != nil { + return conn, err + } + if srv.TCPKeepAlive != 0 { + conn = keepAliveListener{conn, srv.TCPKeepAlive} + } + return conn, nil +} -- cgit v1.2.3