1 files changed, 244 insertions, 0 deletions
diff --git a/lib/agent/webserver.go b/lib/agent/webserver.go
new file mode 100644
index 0000000..4b2e024
--- /dev/null
+++ b/lib/agent/webserver.go
@@ -0,0 +1,244 @@
+package agent
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"path"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/gin-contrib/static"
+	"github.com/gin-gonic/gin"
+	"github.com/googollee/go-socket.io"
+)
+
+// WebServer .
+type WebServer struct {
+	*Context
+	router    *gin.Engine
+	api       *APIService
+	sIOServer *socketio.Server
+	webApp    *gin.RouterGroup
+	stop      chan struct{} // signals intentional stop
+}
+
+const indexFilename = "index.html"
+
+// NewWebServer creates an instance of WebServer
+func NewWebServer(ctx *Context) *WebServer {
+
+	// Setup logging for gin router
+	if ctx.Log.Level == logrus.DebugLevel {
+		gin.SetMode(gin.DebugMode)
+	} else {
+		gin.SetMode(gin.ReleaseMode)
+	}
+
+	// Redirect gin logs into another logger (LogVerboseOut may be stderr or a file)
+	gin.DefaultWriter = ctx.Config.LogVerboseOut
+	gin.DefaultErrorWriter = ctx.Config.LogVerboseOut
+	log.SetOutput(ctx.Config.LogVerboseOut)
+
+	// Creates gin router
+	r := gin.New()
+
+	svr := &WebServer{
+		Context:   ctx,
+		router:    r,
+		api:       nil,
+		sIOServer: nil,
+		webApp:    nil,
+		stop:      make(chan struct{}),
+	}
+
+	return svr
+}
+
+// Serve starts a new instance of the Web Server
+func (s *WebServer) Serve() error {
+	var err error
+
+	// Setup middlewares
+	s.router.Use(gin.Logger())
+	s.router.Use(gin.Recovery())
+	s.router.Use(s.middlewareCORS())
+	s.router.Use(s.middlewareXDSDetails())
+	s.router.Use(s.middlewareCSRF())
+
+	// Create REST API
+	s.api = NewAPIV1(s.Context)
+
+	// Create connections to XDS Servers
+	// XXX - not sure there is no side effect to do it in background !
+	go func() {
+		for _, svrCfg := range s.Config.FileConf.ServersConf {
+			if svr, err := s.api.AddXdsServer(svrCfg); err != nil {
+				// Just log error, don't consider as critical
+				s.Log.Infof("Cannot connect to XDS Server url=%s: %v", svr.BaseURL, err.Error())
+			}
+		}
+	}()
+
+	// Websocket routes
+	s.sIOServer, err = socketio.NewServer(nil)
+	if err != nil {
+		s.Log.Fatalln(err)
+	}
+
+	s.router.GET("/socket.io/", s.socketHandler)
+	s.router.POST("/socket.io/", s.socketHandler)
+	/* TODO: do we want to support ws://...  ?
+	s.router.Handle("WS", "/socket.io/", s.socketHandler)
+	s.router.Handle("WSS", "/socket.io/", s.socketHandler)
+	*/
+
+	// Web Application (serve on / )
+	idxFile := path.Join(s.Config.FileConf.WebAppDir, indexFilename)
+	if _, err := os.Stat(idxFile); err != nil {
+		s.Log.Fatalln("Web app directory not found, check/use webAppDir setting in config file: ", idxFile)
+	}
+	s.Log.Infof("Serve WEB app dir: %s", s.Config.FileConf.WebAppDir)
+	s.router.Use(static.Serve("/", static.LocalFile(s.Config.FileConf.WebAppDir, true)))
+	s.webApp = s.router.Group("/", s.serveIndexFile)
+	{
+		s.webApp.GET("/")
+	}
+
+	// Serve in the background
+	serveError := make(chan error, 1)
+	go func() {
+		fmt.Printf("Web Server running on localhost:%s ...\n", s.Config.FileConf.HTTPPort)
+		serveError <- http.ListenAndServe(":"+s.Config.FileConf.HTTPPort, s.router)
+	}()
+
+	fmt.Printf("XDS agent running...\n")
+
+	// Wait for stop, restart or error signals
+	select {
+	case <-s.stop:
+		// Shutting down permanently
+		s.sessions.Stop()
+		s.Log.Infoln("shutting down (stop)")
+	case err = <-serveError:
+		// Error due to listen/serve failure
+		s.Log.Errorln(err)
+	}
+
+	return nil
+}
+
+// Stop web server
+func (s *WebServer) Stop() {
+	s.api.Stop()
+	close(s.stop)
+}
+
+// serveIndexFile provides initial file (eg. index.html) of webapp
+func (s *WebServer) serveIndexFile(c *gin.Context) {
+	c.HTML(200, indexFilename, gin.H{})
+}
+
+// Add details in Header
+func (s *WebServer) middlewareXDSDetails() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		c.Header("XDS-Agent-Version", s.Config.Version)
+		c.Header("XDS-API-Version", s.Config.APIVersion)
+		c.Next()
+	}
+}
+
+func (s *WebServer) isValidAPIKey(key string) bool {
+	return (s.Config.FileConf.XDSAPIKey != "" && key == s.Config.FileConf.XDSAPIKey)
+}
+
+func (s *WebServer) middlewareCSRF() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		// XXX - not used for now
+		c.Next()
+		return
+		/*
+			// Allow requests carrying a valid API key
+			if s.isValidAPIKey(c.Request.Header.Get("X-API-Key")) {
+				// Set the access-control-allow-origin header for CORS requests
+				// since a valid API key has been provided
+				c.Header("Access-Control-Allow-Origin", "*")
+				c.Next()
+				return
+			}
+
+			// Allow io.socket request
+			if strings.HasPrefix(c.Request.URL.Path, "/socket.io") {
+				c.Next()
+				return
+			}
+
+			// FIXME Add really CSRF support
+
+			// Allow requests for anything not under the protected path prefix,
+			// and set a CSRF cookie if there isn't already a valid one.
+			//if !strings.HasPrefix(c.Request.URL.Path, prefix) {
+			//	cookie, err := c.Cookie("CSRF-Token-" + unique)
+			//	if err != nil || !validCsrfToken(cookie.Value) {
+			//		s.Log.Debugln("new CSRF cookie in response to request for", c.Request.URL)
+			//		c.SetCookie("CSRF-Token-"+unique, newCsrfToken(), 600, "/", "", false, false)
+			//	}
+			//	c.Next()
+			//	return
+			//}
+
+			// Verify the CSRF token
+			//token := c.Request.Header.Get("X-CSRF-Token-" + unique)
+			//if !validCsrfToken(token) {
+			//	c.AbortWithError(403, "CSRF Error")
+			//	return
+			//}
+
+			//c.Next()
+
+			c.AbortWithError(403, fmt.Errorf("Not valid API key"))
+		*/
+	}
+}
+
+// CORS middleware
+func (s *WebServer) middlewareCORS() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		if c.Request.Method == "OPTIONS" {
+			c.Header("Access-Control-Allow-Origin", "*")
+			c.Header("Access-Control-Allow-Headers", "Content-Type, X-API-Key")
+			c.Header("Access-Control-Allow-Methods", "GET, POST, DELETE")
+			c.Header("Access-Control-Max-Age", cookieMaxAge)
+			c.AbortWithStatus(204)
+			return
+		}
+		c.Next()
+	}
+}
+
+// socketHandler is the handler for the "main" websocket connection
+func (s *WebServer) socketHandler(c *gin.Context) {
+
+	// Retrieve user session
+	sess := s.sessions.Get(c)
+	if sess == nil {
+		c.JSON(500, gin.H{"error": "Cannot retrieve session"})
+		return
+	}
+
+	s.sIOServer.On("connection", func(so socketio.Socket) {
+		s.Log.Debugf("WS Connected (SID=%v)", so.Id())
+		s.sessions.UpdateIOSocket(sess.ID, &so)
+
+		so.On("disconnection", func() {
+			s.Log.Debugf("WS disconnected (SID=%v)", so.Id())
+			s.sessions.UpdateIOSocket(sess.ID, nil)
+		})
+	})
+
+	s.sIOServer.On("error", func(so socketio.Socket, err error) {
+		s.Log.Errorf("WS SID=%v Error : %v", so.Id(), err.Error())
+	})
+
+	s.sIOServer.ServeHTTP(c.Writer, c.Request)
+}