vendor github.com/tylerb/graceful and dependencies

vendor/github.com/tylerb/graceful/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Tyler Bunnell
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/tylerb/graceful/graceful.go

@@ -0,0 +1,487 @@
+package graceful
+
+import (
+	"crypto/tls"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+	"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
+	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 {
+		signal.Notify(interrupt, syscall.SIGINT, syscall.SIGTERM)
+	}
+	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
+	interrupt := srv.interruptChan()
+	interrupt <- syscall.SIGINT
+}
+
+// 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{}{}
+		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
+
+	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
+}

vendor/github.com/tylerb/graceful/keepalive_listener.go

@@ -0,0 +1,32 @@
+package graceful
+
+import (
+	"net"
+	"time"
+)
+
+type keepAliveConn interface {
+	SetKeepAlive(bool) error
+	SetKeepAlivePeriod(d time.Duration) error
+}
+
+// keepAliveListener sets TCP keep-alive timeouts on accepted
+// connections. It's used by ListenAndServe and ListenAndServeTLS so
+// dead TCP connections (e.g. closing laptop mid-download) eventually
+// go away.
+type keepAliveListener struct {
+	net.Listener
+	keepAlivePeriod time.Duration
+}
+
+func (ln keepAliveListener) Accept() (net.Conn, error) {
+	c, err := ln.Listener.Accept()
+	if err != nil {
+		return nil, err
+	}
+
+	kac := c.(keepAliveConn)
+	kac.SetKeepAlive(true)
+	kac.SetKeepAlivePeriod(ln.keepAlivePeriod)
+	return c, nil
+}

vendor/github.com/tylerb/graceful/limit_listen.go

@@ -0,0 +1,77 @@
+// Copyright 2013 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package graceful
+
+import (
+	"errors"
+	"net"
+	"sync"
+	"time"
+)
+
+// ErrNotTCP indicates that network connection is not a TCP connection.
+var ErrNotTCP = errors.New("only tcp connections have keepalive")
+
+// LimitListener returns a Listener that accepts at most n simultaneous
+// connections from the provided Listener.
+func LimitListener(l net.Listener, n int) net.Listener {
+	return &limitListener{l, make(chan struct{}, n)}
+}
+
+type limitListener struct {
+	net.Listener
+	sem chan struct{}
+}
+
+func (l *limitListener) acquire() { l.sem <- struct{}{} }
+func (l *limitListener) release() { <-l.sem }
+
+func (l *limitListener) Accept() (net.Conn, error) {
+	l.acquire()
+	c, err := l.Listener.Accept()
+	if err != nil {
+		l.release()
+		return nil, err
+	}
+	return &limitListenerConn{Conn: c, release: l.release}, nil
+}
+
+type limitListenerConn struct {
+	net.Conn
+	releaseOnce sync.Once
+	release     func()
+}
+
+func (l *limitListenerConn) Close() error {
+	err := l.Conn.Close()
+	l.releaseOnce.Do(l.release)
+	return err
+}
+
+func (l *limitListenerConn) SetKeepAlive(doKeepAlive bool) error {
+	tcpc, ok := l.Conn.(*net.TCPConn)
+	if !ok {
+		return ErrNotTCP
+	}
+	return tcpc.SetKeepAlive(doKeepAlive)
+}
+
+func (l *limitListenerConn) SetKeepAlivePeriod(d time.Duration) error {
+	tcpc, ok := l.Conn.(*net.TCPConn)
+	if !ok {
+		return ErrNotTCP
+	}
+	return tcpc.SetKeepAlivePeriod(d)
+}

vendor/github.com/tylerb/graceful/tests/main.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/urfave/negroni"
+	"gopkg.in/tylerb/graceful.v1"
+)
+
+func main() {
+
+	var wg sync.WaitGroup
+
+	wg.Add(3)
+	go func() {
+		n := negroni.New()
+		fmt.Println("Launching server on :3000")
+		graceful.Run(":3000", 0, n)
+		fmt.Println("Terminated server on :3000")
+		wg.Done()
+	}()
+	go func() {
+		n := negroni.New()
+		fmt.Println("Launching server on :3001")
+		graceful.Run(":3001", 0, n)
+		fmt.Println("Terminated server on :3001")
+		wg.Done()
+	}()
+	go func() {
+		n := negroni.New()
+		fmt.Println("Launching server on :3002")
+		graceful.Run(":3002", 0, n)
+		fmt.Println("Terminated server on :3002")
+		wg.Done()
+	}()
+	fmt.Println("Press ctrl+c. All servers should terminate.")
+	wg.Wait()
+
+}

vendor/github.com/urfave/negroni/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Jeremy Saenz
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/urfave/negroni/doc.go

@@ -0,0 +1,25 @@
+// Package negroni is an idiomatic approach to web middleware in Go. It is tiny, non-intrusive, and encourages use of net/http Handlers.
+//
+// If you like the idea of Martini, but you think it contains too much magic, then Negroni is a great fit.
+//
+// For a full guide visit http://github.com/urfave/negroni
+//
+//  package main
+//
+//  import (
+//    "github.com/urfave/negroni"
+//    "net/http"
+//    "fmt"
+//  )
+//
+//  func main() {
+//    mux := http.NewServeMux()
+//    mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
+//      fmt.Fprintf(w, "Welcome to the home page!")
+//    })
+//
+//    n := negroni.Classic()
+//    n.UseHandler(mux)
+//    n.Run(":3000")
+//  }
+package negroni

vendor/github.com/urfave/negroni/logger.go

@@ -0,0 +1,35 @@
+package negroni
+
+import (
+	"log"
+	"net/http"
+	"os"
+	"time"
+)
+
+// ALogger interface
+type ALogger interface {
+	Println(v ...interface{})
+	Printf(format string, v ...interface{})
+}
+
+// Logger is a middleware handler that logs the request as it goes in and the response as it goes out.
+type Logger struct {
+	// ALogger implements just enough log.Logger interface to be compatible with other implementations
+	ALogger
+}
+
+// NewLogger returns a new Logger instance
+func NewLogger() *Logger {
+	return &Logger{log.New(os.Stdout, "[negroni] ", 0)}
+}
+
+func (l *Logger) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+	start := time.Now()
+	l.Printf("Started %s %s", r.Method, r.URL.Path)
+
+	next(rw, r)
+
+	res := rw.(ResponseWriter)
+	l.Printf("Completed %v %s in %v", res.Status(), http.StatusText(res.Status()), time.Since(start))
+}

vendor/github.com/urfave/negroni/negroni.go

@@ -0,0 +1,133 @@
+package negroni
+
+import (
+	"log"
+	"net/http"
+	"os"
+)
+
+// Handler handler is an interface that objects can implement to be registered to serve as middleware
+// in the Negroni middleware stack.
+// ServeHTTP should yield to the next middleware in the chain by invoking the next http.HandlerFunc
+// passed in.
+//
+// If the Handler writes to the ResponseWriter, the next http.HandlerFunc should not be invoked.
+type Handler interface {
+	ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc)
+}
+
+// HandlerFunc is an adapter to allow the use of ordinary functions as Negroni handlers.
+// If f is a function with the appropriate signature, HandlerFunc(f) is a Handler object that calls f.
+type HandlerFunc func(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc)
+
+func (h HandlerFunc) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+	h(rw, r, next)
+}
+
+type middleware struct {
+	handler Handler
+	next    *middleware
+}
+
+func (m middleware) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
+	m.handler.ServeHTTP(rw, r, m.next.ServeHTTP)
+}
+
+// Wrap converts a http.Handler into a negroni.Handler so it can be used as a Negroni
+// middleware. The next http.HandlerFunc is automatically called after the Handler
+// is executed.
+func Wrap(handler http.Handler) Handler {
+	return HandlerFunc(func(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+		handler.ServeHTTP(rw, r)
+		next(rw, r)
+	})
+}
+
+// Negroni is a stack of Middleware Handlers that can be invoked as an http.Handler.
+// Negroni middleware is evaluated in the order that they are added to the stack using
+// the Use and UseHandler methods.
+type Negroni struct {
+	middleware middleware
+	handlers   []Handler
+}
+
+// New returns a new Negroni instance with no middleware preconfigured.
+func New(handlers ...Handler) *Negroni {
+	return &Negroni{
+		handlers:   handlers,
+		middleware: build(handlers),
+	}
+}
+
+// Classic returns a new Negroni instance with the default middleware already
+// in the stack.
+//
+// Recovery - Panic Recovery Middleware
+// Logger - Request/Response Logging
+// Static - Static File Serving
+func Classic() *Negroni {
+	return New(NewRecovery(), NewLogger(), NewStatic(http.Dir("public")))
+}
+
+func (n *Negroni) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
+	n.middleware.ServeHTTP(NewResponseWriter(rw), r)
+}
+
+// Use adds a Handler onto the middleware stack. Handlers are invoked in the order they are added to a Negroni.
+func (n *Negroni) Use(handler Handler) {
+	if handler == nil {
+		panic("handler cannot be nil")
+	}
+
+	n.handlers = append(n.handlers, handler)
+	n.middleware = build(n.handlers)
+}
+
+// UseFunc adds a Negroni-style handler function onto the middleware stack.
+func (n *Negroni) UseFunc(handlerFunc func(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc)) {
+	n.Use(HandlerFunc(handlerFunc))
+}
+
+// UseHandler adds a http.Handler onto the middleware stack. Handlers are invoked in the order they are added to a Negroni.
+func (n *Negroni) UseHandler(handler http.Handler) {
+	n.Use(Wrap(handler))
+}
+
+// UseHandler adds a http.HandlerFunc-style handler function onto the middleware stack.
+func (n *Negroni) UseHandlerFunc(handlerFunc func(rw http.ResponseWriter, r *http.Request)) {
+	n.UseHandler(http.HandlerFunc(handlerFunc))
+}
+
+// Run is a convenience function that runs the negroni stack as an HTTP
+// server. The addr string takes the same format as http.ListenAndServe.
+func (n *Negroni) Run(addr string) {
+	l := log.New(os.Stdout, "[negroni] ", 0)
+	l.Printf("listening on %s", addr)
+	l.Fatal(http.ListenAndServe(addr, n))
+}
+
+// Returns a list of all the handlers in the current Negroni middleware chain.
+func (n *Negroni) Handlers() []Handler {
+	return n.handlers
+}
+
+func build(handlers []Handler) middleware {
+	var next middleware
+
+	if len(handlers) == 0 {
+		return voidMiddleware()
+	} else if len(handlers) > 1 {
+		next = build(handlers[1:])
+	} else {
+		next = voidMiddleware()
+	}
+
+	return middleware{handlers[0], &next}
+}
+
+func voidMiddleware() middleware {
+	return middleware{
+		HandlerFunc(func(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {}),
+		&middleware{},
+	}
+}

vendor/github.com/urfave/negroni/recovery.go

@@ -0,0 +1,65 @@
+package negroni
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"runtime"
+	"runtime/debug"
+)
+
+// Recovery is a Negroni middleware that recovers from any panics and writes a 500 if there was one.
+type Recovery struct {
+	Logger           ALogger
+	PrintStack       bool
+	ErrorHandlerFunc func(interface{})
+	StackAll         bool
+	StackSize        int
+}
+
+// NewRecovery returns a new instance of Recovery
+func NewRecovery() *Recovery {
+	return &Recovery{
+		Logger:     log.New(os.Stdout, "[negroni] ", 0),
+		PrintStack: true,
+		StackAll:   false,
+		StackSize:  1024 * 8,
+	}
+}
+
+func (rec *Recovery) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+	defer func() {
+		if err := recover(); err != nil {
+			if rw.Header().Get("Content-Type") == "" {
+				rw.Header().Set("Content-Type", "text/plain; charset=utf-8")
+			}
+
+			rw.WriteHeader(http.StatusInternalServerError)
+
+			stack := make([]byte, rec.StackSize)
+			stack = stack[:runtime.Stack(stack, rec.StackAll)]
+
+			f := "PANIC: %s\n%s"
+			rec.Logger.Printf(f, err, stack)
+
+			if rec.PrintStack {
+				fmt.Fprintf(rw, f, err, stack)
+			}
+
+			if rec.ErrorHandlerFunc != nil {
+				func() {
+					defer func() {
+						if err := recover(); err != nil {
+							rec.Logger.Printf("provided ErrorHandlerFunc panic'd: %s, trace:\n%s", err, debug.Stack())
+							rec.Logger.Printf("%s\n", debug.Stack())
+						}
+					}()
+					rec.ErrorHandlerFunc(err)
+				}()
+			}
+		}
+	}()
+
+	next(rw, r)
+}

vendor/github.com/urfave/negroni/response_writer.go

@@ -0,0 +1,99 @@
+package negroni
+
+import (
+	"bufio"
+	"fmt"
+	"net"
+	"net/http"
+)
+
+// ResponseWriter is a wrapper around http.ResponseWriter that provides extra information about
+// the response. It is recommended that middleware handlers use this construct to wrap a responsewriter
+// if the functionality calls for it.
+type ResponseWriter interface {
+	http.ResponseWriter
+	http.Flusher
+	// Status returns the status code of the response or 200 if the response has
+	// not been written (as this is the default response code in net/http)
+	Status() int
+	// Written returns whether or not the ResponseWriter has been written.
+	Written() bool
+	// Size returns the size of the response body.
+	Size() int
+	// Before allows for a function to be called before the ResponseWriter has been written to. This is
+	// useful for setting headers or any other operations that must happen before a response has been written.
+	Before(func(ResponseWriter))
+}
+
+type beforeFunc func(ResponseWriter)
+
+// NewResponseWriter creates a ResponseWriter that wraps an http.ResponseWriter
+func NewResponseWriter(rw http.ResponseWriter) ResponseWriter {
+	return &responseWriter{
+		ResponseWriter: rw,
+	}
+}
+
+type responseWriter struct {
+	http.ResponseWriter
+	status      int
+	size        int
+	beforeFuncs []beforeFunc
+}
+
+func (rw *responseWriter) WriteHeader(s int) {
+	rw.status = s
+	rw.callBefore()
+	rw.ResponseWriter.WriteHeader(s)
+}
+
+func (rw *responseWriter) Write(b []byte) (int, error) {
+	if !rw.Written() {
+		// The status will be StatusOK if WriteHeader has not been called yet
+		rw.WriteHeader(http.StatusOK)
+	}
+	size, err := rw.ResponseWriter.Write(b)
+	rw.size += size
+	return size, err
+}
+
+func (rw *responseWriter) Status() int {
+	return rw.status
+}
+
+func (rw *responseWriter) Size() int {
+	return rw.size
+}
+
+func (rw *responseWriter) Written() bool {
+	return rw.status != 0
+}
+
+func (rw *responseWriter) Before(before func(ResponseWriter)) {
+	rw.beforeFuncs = append(rw.beforeFuncs, before)
+}
+
+func (rw *responseWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	hijacker, ok := rw.ResponseWriter.(http.Hijacker)
+	if !ok {
+		return nil, nil, fmt.Errorf("the ResponseWriter doesn't support the Hijacker interface")
+	}
+	return hijacker.Hijack()
+}
+
+func (rw *responseWriter) CloseNotify() <-chan bool {
+	return rw.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+
+func (rw *responseWriter) callBefore() {
+	for i := len(rw.beforeFuncs) - 1; i >= 0; i-- {
+		rw.beforeFuncs[i](rw)
+	}
+}
+
+func (rw *responseWriter) Flush() {
+	flusher, ok := rw.ResponseWriter.(http.Flusher)
+	if ok {
+		flusher.Flush()
+	}
+}

vendor/github.com/urfave/negroni/static.go

@@ -0,0 +1,88 @@
+package negroni
+
+import (
+	"net/http"
+	"path"
+	"strings"
+)
+
+// Static is a middleware handler that serves static files in the given
+// directory/filesystem. If the file does not exist on the filesystem, it
+// passes along to the next middleware in the chain. If you desire "fileserver"
+// type behavior where it returns a 404 for unfound files, you should consider
+// using http.FileServer from the Go stdlib.
+type Static struct {
+	// Dir is the directory to serve static files from
+	Dir http.FileSystem
+	// Prefix is the optional prefix used to serve the static directory content
+	Prefix string
+	// IndexFile defines which file to serve as index if it exists.
+	IndexFile string
+}
+
+// NewStatic returns a new instance of Static
+func NewStatic(directory http.FileSystem) *Static {
+	return &Static{
+		Dir:       directory,
+		Prefix:    "",
+		IndexFile: "index.html",
+	}
+}
+
+func (s *Static) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+	if r.Method != "GET" && r.Method != "HEAD" {
+		next(rw, r)
+		return
+	}
+	file := r.URL.Path
+	// if we have a prefix, filter requests by stripping the prefix
+	if s.Prefix != "" {
+		if !strings.HasPrefix(file, s.Prefix) {
+			next(rw, r)
+			return
+		}
+		file = file[len(s.Prefix):]
+		if file != "" && file[0] != '/' {
+			next(rw, r)
+			return
+		}
+	}
+	f, err := s.Dir.Open(file)
+	if err != nil {
+		// discard the error?
+		next(rw, r)
+		return
+	}
+	defer f.Close()
+
+	fi, err := f.Stat()
+	if err != nil {
+		next(rw, r)
+		return
+	}
+
+	// try to serve index file
+	if fi.IsDir() {
+		// redirect if missing trailing slash
+		if !strings.HasSuffix(r.URL.Path, "/") {
+			http.Redirect(rw, r, r.URL.Path+"/", http.StatusFound)
+			return
+		}
+
+		file = path.Join(file, s.IndexFile)
+		f, err = s.Dir.Open(file)
+		if err != nil {
+			next(rw, r)
+			return
+		}
+		defer f.Close()
+
+		fi, err = f.Stat()
+		if err != nil || fi.IsDir() {
+			next(rw, r)
+			return
+		}
+	}
+
+	http.ServeContent(rw, r, file, fi.ModTime(), f)
+}

vendor/gopkg.in/tylerb/graceful.v1/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Tyler Bunnell
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/gopkg.in/tylerb/graceful.v1/graceful.go

@@ -0,0 +1,487 @@
+package graceful
+
+import (
+	"crypto/tls"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+	"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
+	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 {
+		signal.Notify(interrupt, syscall.SIGINT, syscall.SIGTERM)
+	}
+	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
+	interrupt := srv.interruptChan()
+	interrupt <- syscall.SIGINT
+}
+
+// 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{}{}
+		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
+
+	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
+}

vendor/gopkg.in/tylerb/graceful.v1/keepalive_listener.go

@@ -0,0 +1,32 @@
+package graceful
+
+import (
+	"net"
+	"time"
+)
+
+type keepAliveConn interface {
+	SetKeepAlive(bool) error
+	SetKeepAlivePeriod(d time.Duration) error
+}
+
+// keepAliveListener sets TCP keep-alive timeouts on accepted
+// connections. It's used by ListenAndServe and ListenAndServeTLS so
+// dead TCP connections (e.g. closing laptop mid-download) eventually
+// go away.
+type keepAliveListener struct {
+	net.Listener
+	keepAlivePeriod time.Duration
+}
+
+func (ln keepAliveListener) Accept() (net.Conn, error) {
+	c, err := ln.Listener.Accept()
+	if err != nil {
+		return nil, err
+	}
+
+	kac := c.(keepAliveConn)
+	kac.SetKeepAlive(true)
+	kac.SetKeepAlivePeriod(ln.keepAlivePeriod)
+	return c, nil
+}

vendor/gopkg.in/tylerb/graceful.v1/limit_listen.go

@@ -0,0 +1,77 @@
+// Copyright 2013 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package graceful
+
+import (
+	"errors"
+	"net"
+	"sync"
+	"time"
+)
+
+// ErrNotTCP indicates that network connection is not a TCP connection.
+var ErrNotTCP = errors.New("only tcp connections have keepalive")
+
+// LimitListener returns a Listener that accepts at most n simultaneous
+// connections from the provided Listener.
+func LimitListener(l net.Listener, n int) net.Listener {
+	return &limitListener{l, make(chan struct{}, n)}
+}
+
+type limitListener struct {
+	net.Listener
+	sem chan struct{}
+}
+
+func (l *limitListener) acquire() { l.sem <- struct{}{} }
+func (l *limitListener) release() { <-l.sem }
+
+func (l *limitListener) Accept() (net.Conn, error) {
+	l.acquire()
+	c, err := l.Listener.Accept()
+	if err != nil {
+		l.release()
+		return nil, err
+	}
+	return &limitListenerConn{Conn: c, release: l.release}, nil
+}
+
+type limitListenerConn struct {
+	net.Conn
+	releaseOnce sync.Once
+	release     func()
+}
+
+func (l *limitListenerConn) Close() error {
+	err := l.Conn.Close()
+	l.releaseOnce.Do(l.release)
+	return err
+}
+
+func (l *limitListenerConn) SetKeepAlive(doKeepAlive bool) error {
+	tcpc, ok := l.Conn.(*net.TCPConn)
+	if !ok {
+		return ErrNotTCP
+	}
+	return tcpc.SetKeepAlive(doKeepAlive)
+}
+
+func (l *limitListenerConn) SetKeepAlivePeriod(d time.Duration) error {
+	tcpc, ok := l.Conn.(*net.TCPConn)
+	if !ok {
+		return ErrNotTCP
+	}
+	return tcpc.SetKeepAlivePeriod(d)
+}

vendor/gopkg.in/tylerb/graceful.v1/tests/main.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/urfave/negroni"
+	"gopkg.in/tylerb/graceful.v1"
+)
+
+func main() {
+
+	var wg sync.WaitGroup
+
+	wg.Add(3)
+	go func() {
+		n := negroni.New()
+		fmt.Println("Launching server on :3000")
+		graceful.Run(":3000", 0, n)
+		fmt.Println("Terminated server on :3000")
+		wg.Done()
+	}()
+	go func() {
+		n := negroni.New()
+		fmt.Println("Launching server on :3001")
+		graceful.Run(":3001", 0, n)
+		fmt.Println("Terminated server on :3001")
+		wg.Done()
+	}()
+	go func() {
+		n := negroni.New()
+		fmt.Println("Launching server on :3002")
+		graceful.Run(":3002", 0, n)
+		fmt.Println("Terminated server on :3002")
+		wg.Done()
+	}()
+	fmt.Println("Press ctrl+c. All servers should terminate.")
+	wg.Wait()
+
+}

vendor/manifest

@@ -1184,6 +1184,14 @@
 			"branch": "master",
 			"path": "/assert"
 		},
+		{
+			"importpath": "github.com/tylerb/graceful",
+			"repository": "https://github.com/tylerb/graceful",
+			"vcs": "git",
+			"revision": "50a48b6e73fcc75b45e22c05b79629a67c79e938",
+			"branch": "master",
+			"notests": true
+		},
 		{
 			"importpath": "github.com/ugorji/go/codec",
 			"repository": "https://github.com/ugorji/go",
@@ -1192,6 +1200,14 @@
 			"branch": "master",
 			"path": "/codec"
 		},
+		{
+			"importpath": "github.com/urfave/negroni",
+			"repository": "https://github.com/urfave/negroni",
+			"vcs": "git",
+			"revision": "5d815f907a182b6131cc88af3f17f898b93142a5",
+			"branch": "master",
+			"notests": true
+		},
 		{
 			"importpath": "github.com/weaveworks/go-checkpoint",
 			"repository": "https://github.com/weaveworks/go-checkpoint",
@@ -1318,6 +1334,14 @@
 			"branch": "v1",
 			"notests": true
 		},
+		{
+			"importpath": "gopkg.in/tylerb/graceful.v1",
+			"repository": "https://gopkg.in/tylerb/graceful.v1",
+			"vcs": "git",
+			"revision": "50a48b6e73fcc75b45e22c05b79629a67c79e938",
+			"branch": "master",
+			"notests": true
+		},
 		{
 			"importpath": "gopkg.in/yaml.v1",
 			"repository": "https://gopkg.in/yaml.v1",