rename all remaining packages to internal/ (#12418)

This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`

internal/http/server.go

@@ -0,0 +1,191 @@
+// Copyright (c) 2015-2021 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package http
+
+import (
+	"crypto/tls"
+	"errors"
+	"io/ioutil"
+	"net/http"
+	"runtime/pprof"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	humanize "github.com/dustin/go-humanize"
+
+	"github.com/minio/minio-go/v7/pkg/set"
+	"github.com/minio/minio/internal/config"
+	"github.com/minio/minio/internal/config/api"
+	"github.com/minio/minio/internal/fips"
+	"github.com/minio/pkg/certs"
+	"github.com/minio/pkg/env"
+)
+
+const (
+	serverShutdownPoll = 500 * time.Millisecond
+
+	// DefaultShutdownTimeout - default shutdown timeout used for graceful http server shutdown.
+	DefaultShutdownTimeout = 5 * time.Second
+
+	// DefaultMaxHeaderBytes - default maximum HTTP header size in bytes.
+	DefaultMaxHeaderBytes = 1 * humanize.MiByte
+)
+
+// Server - extended http.Server supports multiple addresses to serve and enhanced connection handling.
+type Server struct {
+	http.Server
+	Addrs           []string      // addresses on which the server listens for new connection.
+	ShutdownTimeout time.Duration // timeout used for graceful server shutdown.
+	listenerMutex   sync.Mutex    // to guard 'listener' field.
+	listener        *httpListener // HTTP listener for all 'Addrs' field.
+	inShutdown      uint32        // indicates whether the server is in shutdown or not
+	requestCount    int32         // counter holds no. of request in progress.
+}
+
+// GetRequestCount - returns number of request in progress.
+func (srv *Server) GetRequestCount() int {
+	return int(atomic.LoadInt32(&srv.requestCount))
+}
+
+// Start - start HTTP server
+func (srv *Server) Start() (err error) {
+	// Take a copy of server fields.
+	var tlsConfig *tls.Config
+	if srv.TLSConfig != nil {
+		tlsConfig = srv.TLSConfig.Clone()
+	}
+	handler := srv.Handler // if srv.Handler holds non-synced state -> possible data race
+
+	addrs := set.CreateStringSet(srv.Addrs...).ToSlice() // copy and remove duplicates
+
+	// Create new HTTP listener.
+	var listener *httpListener
+	listener, err = newHTTPListener(
+		addrs,
+	)
+	if err != nil {
+		return err
+	}
+
+	// Wrap given handler to do additional
+	// * return 503 (service unavailable) if the server in shutdown.
+	wrappedHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// If server is in shutdown.
+		if atomic.LoadUint32(&srv.inShutdown) != 0 {
+			// To indicate disable keep-alives
+			w.Header().Set("Connection", "close")
+			w.WriteHeader(http.StatusForbidden)
+			w.Write([]byte(http.ErrServerClosed.Error()))
+			w.(http.Flusher).Flush()
+			return
+		}
+
+		atomic.AddInt32(&srv.requestCount, 1)
+		defer atomic.AddInt32(&srv.requestCount, -1)
+
+		// Handle request using passed handler.
+		handler.ServeHTTP(w, r)
+	})
+
+	srv.listenerMutex.Lock()
+	srv.Handler = wrappedHandler
+	srv.listener = listener
+	srv.listenerMutex.Unlock()
+
+	// Start servicing with listener.
+	if tlsConfig != nil {
+		return srv.Server.Serve(tls.NewListener(listener, tlsConfig))
+	}
+	return srv.Server.Serve(listener)
+}
+
+// Shutdown - shuts down HTTP server.
+func (srv *Server) Shutdown() error {
+	srv.listenerMutex.Lock()
+	if srv.listener == nil {
+		srv.listenerMutex.Unlock()
+		return http.ErrServerClosed
+	}
+	srv.listenerMutex.Unlock()
+
+	if atomic.AddUint32(&srv.inShutdown, 1) > 1 {
+		// shutdown in progress
+		return http.ErrServerClosed
+	}
+
+	// Close underneath HTTP listener.
+	srv.listenerMutex.Lock()
+	err := srv.listener.Close()
+	srv.listenerMutex.Unlock()
+	if err != nil {
+		return err
+	}
+
+	// Wait for opened connection to be closed up to Shutdown timeout.
+	shutdownTimeout := srv.ShutdownTimeout
+	shutdownTimer := time.NewTimer(shutdownTimeout)
+	ticker := time.NewTicker(serverShutdownPoll)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-shutdownTimer.C:
+			// Write all running goroutines.
+			tmp, err := ioutil.TempFile("", "minio-goroutines-*.txt")
+			if err == nil {
+				_ = pprof.Lookup("goroutine").WriteTo(tmp, 1)
+				tmp.Close()
+				return errors.New("timed out. some connections are still active. goroutines written to " + tmp.Name())
+			}
+			return errors.New("timed out. some connections are still active")
+		case <-ticker.C:
+			if atomic.LoadInt32(&srv.requestCount) <= 0 {
+				return nil
+			}
+		}
+	}
+}
+
+// NewServer - creates new HTTP server using given arguments.
+func NewServer(addrs []string, handler http.Handler, getCert certs.GetCertificateFunc) *Server {
+	secureCiphers := env.Get(api.EnvAPISecureCiphers, config.EnableOn) == config.EnableOn
+
+	var tlsConfig *tls.Config
+	if getCert != nil {
+		tlsConfig = &tls.Config{
+			PreferServerCipherSuites: true,
+			MinVersion:               tls.VersionTLS12,
+			NextProtos:               []string{"http/1.1", "h2"},
+			GetCertificate:           getCert,
+		}
+		if secureCiphers || fips.Enabled {
+			tlsConfig.CipherSuites = fips.CipherSuitesTLS()
+			tlsConfig.CurvePreferences = fips.EllipticCurvesTLS()
+		}
+	}
+
+	httpServer := &Server{
+		Addrs:           addrs,
+		ShutdownTimeout: DefaultShutdownTimeout,
+	}
+	httpServer.Handler = handler
+	httpServer.TLSConfig = tlsConfig
+	httpServer.MaxHeaderBytes = DefaultMaxHeaderBytes
+
+	return httpServer
+}