lib/webserver/server.go

   1 package webserver
   2
   3 import (
   4         "fmt"
   5         "net/http"
   6         "os"
   7
   8         "path"
   9
  10         "github.com/Sirupsen/logrus"
  11         "github.com/gin-contrib/static"
  12         "github.com/gin-gonic/gin"
  13         "github.com/googollee/go-socket.io"
  14         "github.com/iotbzh/xds-server/lib/apiv1"
  15         "github.com/iotbzh/xds-server/lib/crosssdk"
  16         "github.com/iotbzh/xds-server/lib/model"
  17         "github.com/iotbzh/xds-server/lib/session"
  18         "github.com/iotbzh/xds-server/lib/xdsconfig"
  19 )
  20
  21 // Server .
  22 type Server struct {
  23         router    *gin.Engine
  24         api       *apiv1.APIService
  25         sIOServer *socketio.Server
  26         webApp    *gin.RouterGroup
  27         cfg       *xdsconfig.Config
  28         sessions  *session.Sessions
  29         mfolder   *model.Folder
  30         sdks      *crosssdk.SDKs
  31         log       *logrus.Logger
  32         stop      chan struct{} // signals intentional stop
  33 }
  34
  35 const indexFilename = "index.html"
  36 const cookieMaxAge = "3600"
  37
  38 // New creates an instance of Server
  39 func New(cfg *xdsconfig.Config, mfolder *model.Folder, sdks *crosssdk.SDKs, log *logrus.Logger) *Server {
  40
  41         // Setup logging for gin router
  42         if log.Level == logrus.DebugLevel {
  43                 gin.SetMode(gin.DebugMode)
  44         } else {
  45                 gin.SetMode(gin.ReleaseMode)
  46         }
  47
  48         // TODO
  49         //  - try to bind gin DefaultWriter & DefaultErrorWriter to logrus logger
  50         //  - try to fix pb about isTerminal=false when out is in VSC Debug Console
  51         //gin.DefaultWriter = ??
  52         //gin.DefaultErrorWriter = ??
  53
  54         // Creates gin router
  55         r := gin.New()
  56
  57         svr := &Server{
  58                 router:    r,
  59                 api:       nil,
  60                 sIOServer: nil,
  61                 webApp:    nil,
  62                 cfg:       cfg,
  63                 sessions:  nil,
  64                 mfolder:   mfolder,
  65                 sdks:      sdks,
  66                 log:       log,
  67                 stop:      make(chan struct{}),
  68         }
  69
  70         return svr
  71 }
  72
  73 // Serve starts a new instance of the Web Server
  74 func (s *Server) Serve() error {
  75         var err error
  76
  77         // Setup middlewares
  78         s.router.Use(gin.Logger())
  79         s.router.Use(gin.Recovery())
  80         s.router.Use(s.middlewareXDSDetails())
  81         s.router.Use(s.middlewareCORS())
  82
  83         // Sessions manager
  84         s.sessions = session.NewClientSessions(s.router, s.log, cookieMaxAge)
  85
  86         // Create REST API
  87         s.api = apiv1.New(s.router, s.sessions, s.cfg, s.mfolder, s.sdks)
  88
  89         // Websocket routes
  90         s.sIOServer, err = socketio.NewServer(nil)
  91         if err != nil {
  92                 s.log.Fatalln(err)
  93         }
  94
  95         s.router.GET("/socket.io/", s.socketHandler)
  96         s.router.POST("/socket.io/", s.socketHandler)
  97         /* TODO: do we want to support ws://...  ?
  98         s.router.Handle("WS", "/socket.io/", s.socketHandler)
  99         s.router.Handle("WSS", "/socket.io/", s.socketHandler)
 100         */
 101
 102         // Web Application (serve on / )
 103         idxFile := path.Join(s.cfg.WebAppDir, indexFilename)
 104         if _, err := os.Stat(idxFile); err != nil {
 105                 s.log.Fatalln("Web app directory not found, check/use webAppDir setting in config file: ", idxFile)
 106         }
 107         s.log.Infof("Serve WEB app dir: %s", s.cfg.WebAppDir)
 108         s.router.Use(static.Serve("/", static.LocalFile(s.cfg.WebAppDir, true)))
 109         s.webApp = s.router.Group("/", s.serveIndexFile)
 110         {
 111                 s.webApp.GET("/")
 112         }
 113
 114         // Serve in the background
 115         serveError := make(chan error, 1)
 116         go func() {
 117                 fmt.Printf("Web Server running on localhost:%s ...\n", s.cfg.HTTPPort)
 118                 serveError <- http.ListenAndServe(":"+s.cfg.HTTPPort, s.router)
 119         }()
 120
 121         // Wait for stop, restart or error signals
 122         select {
 123         case <-s.stop:
 124                 // Shutting down permanently
 125                 s.sessions.Stop()
 126                 s.log.Infoln("shutting down (stop)")
 127         case err = <-serveError:
 128                 // Error due to listen/serve failure
 129                 s.log.Errorln(err)
 130         }
 131
 132         return nil
 133 }
 134
 135 // Stop web server
 136 func (s *Server) Stop() {
 137         close(s.stop)
 138 }
 139
 140 // serveIndexFile provides initial file (eg. index.html) of webapp
 141 func (s *Server) serveIndexFile(c *gin.Context) {
 142         c.HTML(200, indexFilename, gin.H{})
 143 }
 144
 145 // Add details in Header
 146 func (s *Server) middlewareXDSDetails() gin.HandlerFunc {
 147         return func(c *gin.Context) {
 148                 c.Header("XDS-Version", s.cfg.Version)
 149                 c.Header("XDS-API-Version", s.cfg.APIVersion)
 150                 c.Next()
 151         }
 152 }
 153
 154 // CORS middleware
 155 func (s *Server) middlewareCORS() gin.HandlerFunc {
 156         return func(c *gin.Context) {
 157
 158                 if c.Request.Method == "OPTIONS" {
 159                         c.Header("Access-Control-Allow-Origin", "*")
 160                         c.Header("Access-Control-Allow-Headers", "Content-Type")
 161                         c.Header("Access-Control-Allow-Methods", "POST, DELETE, GET, PUT")
 162                         c.Header("Content-Type", "application/json")
 163                         c.Header("Access-Control-Max-Age", cookieMaxAge)
 164                         c.AbortWithStatus(204)
 165                         return
 166                 }
 167
 168                 c.Next()
 169         }
 170 }
 171
 172 // socketHandler is the handler for the "main" websocket connection
 173 func (s *Server) socketHandler(c *gin.Context) {
 174
 175         // Retrieve user session
 176         sess := s.sessions.Get(c)
 177         if sess == nil {
 178                 c.JSON(500, gin.H{"error": "Cannot retrieve session"})
 179                 return
 180         }
 181
 182         s.sIOServer.On("connection", func(so socketio.Socket) {
 183                 s.log.Debugf("WS Connected (SID=%v)", so.Id())
 184                 s.sessions.UpdateIOSocket(sess.ID, &so)
 185
 186                 so.On("disconnection", func() {
 187                         s.log.Debugf("WS disconnected (SID=%v)", so.Id())
 188                         s.sessions.UpdateIOSocket(sess.ID, nil)
 189                 })
 190         })
 191
 192         s.sIOServer.On("error", func(so socketio.Socket, err error) {
 193                 s.log.Errorf("WS SID=%v Error : %v", so.Id(), err.Error())
 194         })
 195
 196         s.sIOServer.ServeHTTP(c.Writer, c.Request)
 197 }