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| 1 | +// Copyright (c) 2022 Gitpod GmbH. All rights reserved. |
| 2 | +// Licensed under the GNU Affero General Public License (AGPL). |
| 3 | +// See License-AGPL.txt in the project root for license information. |
| 4 | + |
| 5 | +package baseserver |
| 6 | + |
| 7 | +import ( |
| 8 | + "context" |
| 9 | + "fmt" |
| 10 | + "github.com/sirupsen/logrus" |
| 11 | + "google.golang.org/grpc" |
| 12 | + "net" |
| 13 | + "net/http" |
| 14 | + "os" |
| 15 | + "os/signal" |
| 16 | + "syscall" |
| 17 | +) |
| 18 | + |
| 19 | +func New(name string, opts ...Option) (*Server, error) { |
| 20 | + cfg, err := evaluateOptions(defaultConfig(), opts...) |
| 21 | + if err != nil { |
| 22 | + return nil, fmt.Errorf("invalid config: %w", err) |
| 23 | + } |
| 24 | + |
| 25 | + server := &Server{ |
| 26 | + Name: name, |
| 27 | + cfg: cfg, |
| 28 | + } |
| 29 | + |
| 30 | + if initErr := server.initializeHTTP(); initErr != nil { |
| 31 | + return nil, fmt.Errorf("failed to initialize http server: %w", initErr) |
| 32 | + } |
| 33 | + if initErr := server.initializeGRPC(); initErr != nil { |
| 34 | + return nil, fmt.Errorf("failed to initialize grpc server: %w", initErr) |
| 35 | + } |
| 36 | + |
| 37 | + return server, nil |
| 38 | +} |
| 39 | + |
| 40 | +type Server struct { |
| 41 | + // Name is the name of this server, used for logging context |
| 42 | + Name string |
| 43 | + |
| 44 | + cfg *config |
| 45 | + |
| 46 | + // http is an http Server |
| 47 | + http *http.Server |
| 48 | + httpMux *http.ServeMux |
| 49 | + httpListener net.Listener |
| 50 | + |
| 51 | + // grpc is a grpc Server |
| 52 | + grpc *grpc.Server |
| 53 | + grpcListener net.Listener |
| 54 | + |
| 55 | + // listening indicates the server is serving. When closed, the server is in the process of graceful termination. |
| 56 | + listening chan struct{} |
| 57 | +} |
| 58 | + |
| 59 | +func (s *Server) ListenAndServe() error { |
| 60 | + var err error |
| 61 | + s.grpcListener, err = net.Listen("tcp", fmt.Sprintf(":%d", s.cfg.grpcPort)) |
| 62 | + if err != nil { |
| 63 | + return fmt.Errorf("failed to acquire port %d", s.cfg.grpcPort) |
| 64 | + } |
| 65 | + |
| 66 | + s.httpListener, err = net.Listen("tcp", fmt.Sprintf(":%d", s.cfg.httpPort)) |
| 67 | + if err != nil { |
| 68 | + return fmt.Errorf("failed to acquire port %d", s.cfg.grpcPort) |
| 69 | + } |
| 70 | + |
| 71 | + errors := make(chan error) |
| 72 | + defer close(errors) |
| 73 | + s.listening = make(chan struct{}) |
| 74 | + |
| 75 | + go func() { |
| 76 | + s.Logger(). |
| 77 | + WithField("protocol", "grpc"). |
| 78 | + Infof("Serving gRPC on %s", s.grpcListener.Addr().String()) |
| 79 | + if serveErr := s.grpc.Serve(s.grpcListener); serveErr != nil { |
| 80 | + if s.isClosing() { |
| 81 | + return |
| 82 | + } |
| 83 | + |
| 84 | + errors <- serveErr |
| 85 | + } |
| 86 | + }() |
| 87 | + |
| 88 | + go func() { |
| 89 | + s.Logger(). |
| 90 | + WithField("protocol", "http"). |
| 91 | + Infof("Serving http on %s", s.httpListener.Addr().String()) |
| 92 | + if serveErr := s.http.Serve(s.httpListener); serveErr != nil { |
| 93 | + if s.isClosing() { |
| 94 | + return |
| 95 | + } |
| 96 | + |
| 97 | + errors <- serveErr |
| 98 | + } |
| 99 | + }() |
| 100 | + |
| 101 | + signals := make(chan os.Signal, 1) |
| 102 | + signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM) |
| 103 | + |
| 104 | + // Await operating system signals, or server errors. |
| 105 | + select { |
| 106 | + case sig := <-signals: |
| 107 | + s.Logger().Infof("Received system signal %s, closing server.", sig.String()) |
| 108 | + if closeErr := s.Close(); closeErr != nil { |
| 109 | + s.Logger().WithError(closeErr).Error("Failed to close server.") |
| 110 | + return closeErr |
| 111 | + } |
| 112 | + |
| 113 | + return nil |
| 114 | + case serverErr := <-errors: |
| 115 | + s.Logger().WithError(serverErr).Errorf("Server encountered an error. Closing remaining servers.") |
| 116 | + if closeErr := s.Close(); closeErr != nil { |
| 117 | + return fmt.Errorf("failed to close server after one of the servers errored: %w", closeErr) |
| 118 | + } |
| 119 | + |
| 120 | + return serverErr |
| 121 | + } |
| 122 | +} |
| 123 | + |
| 124 | +func (s *Server) Close() error { |
| 125 | + ctx, cancel := context.WithTimeout(context.Background(), s.cfg.closeTimeout) |
| 126 | + defer cancel() |
| 127 | + |
| 128 | + return s.close(ctx) |
| 129 | +} |
| 130 | + |
| 131 | +func (s *Server) Logger() *logrus.Entry { |
| 132 | + return s.cfg.logger |
| 133 | +} |
| 134 | + |
| 135 | +func (s *Server) HTTPAddress() string { |
| 136 | + protocol := "http" |
| 137 | + return fmt.Sprintf("%s://%s:%d", protocol, s.cfg.hostname, s.cfg.httpPort) |
| 138 | +} |
| 139 | + |
| 140 | +func (s *Server) GRPCAddress() string { |
| 141 | + protocol := "http" |
| 142 | + return fmt.Sprintf("%s://%s:%d", protocol, s.cfg.hostname, s.cfg.grpcPort) |
| 143 | +} |
| 144 | + |
| 145 | +func (s *Server) HTTPMux() *http.ServeMux { |
| 146 | + return s.httpMux |
| 147 | +} |
| 148 | + |
| 149 | +func (s *Server) close(ctx context.Context) error { |
| 150 | + if s.listening == nil { |
| 151 | + return fmt.Errorf("server is not running, invalid close operaiton") |
| 152 | + } |
| 153 | + |
| 154 | + if s.isClosing() { |
| 155 | + s.Logger().Info("Server is already closing.") |
| 156 | + return nil |
| 157 | + } |
| 158 | + |
| 159 | + s.Logger().Info("Received graceful shutdown request.") |
| 160 | + close(s.listening) |
| 161 | + |
| 162 | + s.grpc.GracefulStop() |
| 163 | + // s.grpc.GracefulStop() also closes the underlying net.Listener, we just release the reference. |
| 164 | + s.grpcListener = nil |
| 165 | + s.Logger().Info("GRPC server terminated.") |
| 166 | + |
| 167 | + if err := s.http.Shutdown(ctx); err != nil { |
| 168 | + return fmt.Errorf("failed to close http server: %w", err) |
| 169 | + } |
| 170 | + // s.http.Shutdown() also closes the underlying net.Listener, we just release the reference. |
| 171 | + s.httpListener = nil |
| 172 | + s.Logger().Info("HTTP server terminated.") |
| 173 | + |
| 174 | + return nil |
| 175 | +} |
| 176 | + |
| 177 | +func (s *Server) isClosing() bool { |
| 178 | + select { |
| 179 | + case <-s.listening: |
| 180 | + // listening channel is closed, we're in graceful shutdown mode |
| 181 | + return true |
| 182 | + default: |
| 183 | + return false |
| 184 | + } |
| 185 | +} |
| 186 | + |
| 187 | +func (s *Server) initializeHTTP() error { |
| 188 | + s.httpMux = s.newHTTPMux() |
| 189 | + s.http = &http.Server{ |
| 190 | + Addr: fmt.Sprintf(":%d", s.cfg.httpPort), |
| 191 | + Handler: s.httpMux, |
| 192 | + } |
| 193 | + |
| 194 | + return nil |
| 195 | +} |
| 196 | + |
| 197 | +func (s *Server) newHTTPMux() *http.ServeMux { |
| 198 | + mux := http.NewServeMux() |
| 199 | + // TODO(milan): Use a ready/health package already used in ws-manager |
| 200 | + mux.HandleFunc("/ready", func(w http.ResponseWriter, r *http.Request) { |
| 201 | + _, _ = w.Write([]byte(`ready`)) |
| 202 | + }) |
| 203 | + |
| 204 | + return mux |
| 205 | +} |
| 206 | + |
| 207 | +func (s *Server) initializeGRPC() error { |
| 208 | + s.grpc = grpc.NewServer() |
| 209 | + |
| 210 | + return nil |
| 211 | +} |
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