Huge refactor to have everything working with socket.io

It fixes lots of bugs, can fallback to long polling, resize viewport of
terminals and share clients state of the session, so they all see the
same thing.

handlers/ws.go

@@ -0,0 +1,86 @@
+package handlers
+
+import (
+	"log"
+
+	"github.com/franela/play-with-docker/services"
+	"github.com/googollee/go-socket.io"
+	"github.com/gorilla/mux"
+)
+
+func WS(so socketio.Socket) {
+	vars := mux.Vars(so.Request())
+
+	sessionId := vars["sessionId"]
+
+	session := services.GetSession(sessionId)
+	if session == nil {
+		log.Printf("Session with id [%s] does not exist!\n", sessionId)
+		return
+	}
+
+	session.AddNewClient(services.NewClient(so, session))
+}
+func WSError(so socketio.Socket) {
+	log.Println("error ws")
+}
+
+/*
+	so.Join(sessionId)
+
+	// TODO: Reset terminal geometry
+
+	so.On("resize", func(cols, rows int) {
+		// TODO: Reset terminal geometry
+	})
+
+	so.On("disconnection", func() {
+		//TODO: reset the best terminal geometry
+	})
+
+	ctx := context.Background()
+
+	session := services.GetSession(sessionId)
+	instance := services.GetInstance(session, instanceName)
+
+	if instance.Stdout == nil {
+		id, err := services.CreateExecConnection(instance.Name, ctx)
+		if err != nil {
+			return
+		}
+		conn, err := services.AttachExecConnection(id, ctx)
+		if err != nil {
+			return
+		}
+
+		encoder := encoding.Replacement.NewEncoder()
+		instance.Conn = conn
+		instance.Stdout = &cookoo.MultiWriter{}
+		instance.Stdout.Init()
+		u1 := uuid.NewV4()
+		instance.Stdout.AddWriter(u1.String(), ws)
+		go func() {
+			io.Copy(encoder.Writer(instance.Stdout), instance.Conn.Reader)
+			instance.Stdout.RemoveWriter(u1.String())
+		}()
+		go func() {
+			io.Copy(instance.Conn.Conn, ws)
+			instance.Stdout.RemoveWriter(u1.String())
+		}()
+		select {
+		case <-ctx.Done():
+		}
+	} else {
+		u1 := uuid.NewV4()
+		instance.Stdout.AddWriter(u1.String(), ws)
+
+		go func() {
+			io.Copy(instance.Conn.Conn, ws)
+			instance.Stdout.RemoveWriter(u1.String())
+		}()
+		select {
+		case <-ctx.Done():
+		}
+	}
+}
+*/