lib/webserver/server.go

   1 package webserver
   2
   3 import (
   4         "fmt"
   5         "log"
   6         "net/http"
   7         "os"
   8
   9         "path"
  10
  11         "github.com/Sirupsen/logrus"
  12         "github.com/gin-contrib/static"
  13         "github.com/gin-gonic/gin"
  14         "github.com/googollee/go-socket.io"
  15         "github.com/iotbzh/xds-server/lib/apiv1"
  16         "github.com/iotbzh/xds-server/lib/crosssdk"
  17         "github.com/iotbzh/xds-server/lib/model"
  18         "github.com/iotbzh/xds-server/lib/session"
  19         "github.com/iotbzh/xds-server/lib/xdsconfig"
  20 )
  21
  22 // Server .
  23 type Server struct {
  24         router    *gin.Engine
  25         api       *apiv1.APIService
  26         sIOServer *socketio.Server
  27         webApp    *gin.RouterGroup
  28         cfg       *xdsconfig.Config
  29         sessions  *session.Sessions
  30         mfolders  *model.Folders
  31         sdks      *crosssdk.SDKs
  32         log       *logrus.Logger
  33         stop      chan struct{} // signals intentional stop
  34 }
  35
  36 const indexFilename = "index.html"
  37 const cookieMaxAge = "3600"
  38
  39 // New creates an instance of Server
  40 func New(cfg *xdsconfig.Config, mfolders *model.Folders, sdks *crosssdk.SDKs, logr *logrus.Logger) *Server {
  41
  42         // Setup logging for gin router
  43         if logr.Level == logrus.DebugLevel {
  44                 gin.SetMode(gin.DebugMode)
  45         } else {
  46                 gin.SetMode(gin.ReleaseMode)
  47         }
  48
  49         // Redirect gin logs into another logger (LogVerboseOut may be stderr or a file)
  50         gin.DefaultWriter = cfg.LogVerboseOut
  51         gin.DefaultErrorWriter = cfg.LogVerboseOut
  52         log.SetOutput(cfg.LogVerboseOut)
  53
  54         // FIXME - fix pb about isTerminal=false when out is in VSC Debug Console
  55
  56         // Creates gin router
  57         r := gin.New()
  58
  59         svr := &Server{
  60                 router:    r,
  61                 api:       nil,
  62                 sIOServer: nil,
  63                 webApp:    nil,
  64                 cfg:       cfg,
  65                 sessions:  nil,
  66                 mfolders:  mfolders,
  67                 sdks:      sdks,
  68                 log:       logr,
  69                 stop:      make(chan struct{}),
  70         }
  71
  72         return svr
  73 }
  74
  75 // Serve starts a new instance of the Web Server
  76 func (s *Server) Serve() error {
  77         var err error
  78
  79         // Setup middlewares
  80         s.router.Use(gin.Logger())
  81         s.router.Use(gin.Recovery())
  82         s.router.Use(s.middlewareXDSDetails())
  83         s.router.Use(s.middlewareCORS())
  84
  85         // Sessions manager
  86         s.sessions = session.NewClientSessions(s.router, s.log, cookieMaxAge)
  87
  88         // Create REST API
  89         s.api = apiv1.New(s.router, s.sessions, s.cfg, s.mfolders, s.sdks)
  90
  91         // Websocket routes
  92         s.sIOServer, err = socketio.NewServer(nil)
  93         if err != nil {
  94                 s.log.Fatalln(err)
  95         }
  96
  97         s.router.GET("/socket.io/", s.socketHandler)
  98         s.router.POST("/socket.io/", s.socketHandler)
  99         /* TODO: do we want to support ws://...  ?
 100         s.router.Handle("WS", "/socket.io/", s.socketHandler)
 101         s.router.Handle("WSS", "/socket.io/", s.socketHandler)
 102         */
 103
 104         // Web Application (serve on / )
 105         idxFile := path.Join(s.cfg.FileConf.WebAppDir, indexFilename)
 106         if _, err := os.Stat(idxFile); err != nil {
 107                 s.log.Fatalln("Web app directory not found, check/use webAppDir setting in config file: ", idxFile)
 108         }
 109         s.log.Infof("Serve WEB app dir: %s", s.cfg.FileConf.WebAppDir)
 110         s.router.Use(static.Serve("/", static.LocalFile(s.cfg.FileConf.WebAppDir, true)))
 111         s.webApp = s.router.Group("/", s.serveIndexFile)
 112         {
 113                 s.webApp.GET("/")
 114         }
 115
 116         // Serve in the background
 117         serveError := make(chan error, 1)
 118         go func() {
 119                 msg := fmt.Sprintf("Web Server running on localhost:%s ...\n", s.cfg.FileConf.HTTPPort)
 120                 s.log.Infof(msg)
 121                 fmt.Printf(msg)
 122                 serveError <- http.ListenAndServe(":"+s.cfg.FileConf.HTTPPort, s.router)
 123         }()
 124
 125         // Wait for stop, restart or error signals
 126         select {
 127         case <-s.stop:
 128                 // Shutting down permanently
 129                 s.sessions.Stop()
 130                 s.log.Infoln("shutting down (stop)")
 131         case err = <-serveError:
 132                 // Error due to listen/serve failure
 133                 s.log.Errorln(err)
 134         }
 135
 136         return nil
 137 }
 138
 139 // Stop web server
 140 func (s *Server) Stop() {
 141         close(s.stop)
 142 }
 143
 144 // serveIndexFile provides initial file (eg. index.html) of webapp
 145 func (s *Server) serveIndexFile(c *gin.Context) {
 146         c.HTML(200, indexFilename, gin.H{})
 147 }
 148
 149 // Add details in Header
 150 func (s *Server) middlewareXDSDetails() gin.HandlerFunc {
 151         return func(c *gin.Context) {
 152                 c.Header("XDS-Version", s.cfg.Version)
 153                 c.Header("XDS-API-Version", s.cfg.APIVersion)
 154                 c.Next()
 155         }
 156 }
 157
 158 // CORS middleware
 159 func (s *Server) middlewareCORS() gin.HandlerFunc {
 160         return func(c *gin.Context) {
 161                 if c.Request.Method == "OPTIONS" {
 162                         c.Header("Access-Control-Allow-Origin", "*")
 163                         c.Header("Access-Control-Allow-Headers", "Content-Type")
 164                         c.Header("Access-Control-Allow-Methods", "GET, POST, DELETE")
 165                         c.Header("Access-Control-Max-Age", cookieMaxAge)
 166                         c.AbortWithStatus(204)
 167                         return
 168                 }
 169
 170                 c.Next()
 171         }
 172 }
 173
 174 // socketHandler is the handler for the "main" websocket connection
 175 func (s *Server) socketHandler(c *gin.Context) {
 176
 177         // Retrieve user session
 178         sess := s.sessions.Get(c)
 179         if sess == nil {
 180                 c.JSON(500, gin.H{"error": "Cannot retrieve session"})
 181                 return
 182         }
 183
 184         s.sIOServer.On("connection", func(so socketio.Socket) {
 185                 s.log.Debugf("WS Connected (SID=%v)", so.Id())
 186                 s.sessions.UpdateIOSocket(sess.ID, &so)
 187
 188                 so.On("disconnection", func() {
 189                         s.log.Debugf("WS disconnected (SID=%v)", so.Id())
 190                         s.sessions.UpdateIOSocket(sess.ID, nil)
 191                 })
 192         })
 193
 194         s.sIOServer.On("error", func(so socketio.Socket, err error) {
 195                 s.log.Errorf("WS SID=%v Error : %v", so.Id(), err.Error())
 196         })
 197
 198         s.sIOServer.ServeHTTP(c.Writer, c.Request)
 199 }