Refactor: Rename NanoKVM to BatchuKVM and update server URL

server/service/vm/terminal.go

@@ -0,0 +1,110 @@
+package vm
+
+import (
+	"encoding/json"
+	"net/http"
+	"os"
+	"os/exec"
+	"time"
+
+	"github.com/creack/pty"
+	"github.com/gin-gonic/gin"
+	"github.com/gorilla/websocket"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	messageWait    = 10 * time.Second
+	maxMessageSize = 1024
+)
+
+type WinSize struct {
+	Rows uint16 `json:"rows"`
+	Cols uint16 `json:"cols"`
+}
+
+var upgrader = websocket.Upgrader{
+	ReadBufferSize:  maxMessageSize,
+	WriteBufferSize: maxMessageSize,
+	CheckOrigin: func(r *http.Request) bool {
+		return true
+	},
+}
+
+func (s *Service) Terminal(c *gin.Context) {
+	ws, err := upgrader.Upgrade(c.Writer, c.Request, nil)
+	if err != nil {
+		log.Errorf("failed to init websocket: %s", err)
+		return
+	}
+	defer func() {
+		_ = ws.Close()
+	}()
+
+	cmd := exec.Command("/bin/sh")
+	ptmx, err := pty.Start(cmd)
+	if err != nil {
+		log.Errorf("failed to start pty: %s", err)
+		return
+	}
+	defer func() {
+		_ = ptmx.Close()
+		_ = cmd.Process.Kill()
+	}()
+
+	go wsWrite(ws, ptmx)
+	wsRead(ws, ptmx)
+}
+
+// pty to ws
+func wsWrite(ws *websocket.Conn, ptmx *os.File) {
+	data := make([]byte, maxMessageSize)
+
+	for {
+		n, err := ptmx.Read(data)
+		if err != nil {
+			return
+		}
+
+		if n > 0 {
+			_ = ws.SetWriteDeadline(time.Now().Add(messageWait))
+
+			err = ws.WriteMessage(websocket.BinaryMessage, data[:n])
+			if err != nil {
+				log.Errorf("write ws message failed: %s", err)
+				return
+			}
+		}
+	}
+}
+
+// ws to pty
+func wsRead(ws *websocket.Conn, ptmx *os.File) {
+	var zeroTime time.Time
+	_ = ws.SetReadDeadline(zeroTime)
+
+	for {
+		msgType, p, err := ws.ReadMessage()
+		if err != nil {
+			return
+		}
+
+		// resize message
+		if msgType == websocket.BinaryMessage {
+			var winSize WinSize
+			if err := json.Unmarshal(p, &winSize); err == nil {
+				_ = pty.Setsize(ptmx, &pty.Winsize{
+					Rows: winSize.Rows,
+					Cols: winSize.Cols,
+				})
+			}
+			continue
+		}
+
+		_, err = ptmx.Write(p)
+		if err != nil {
+			log.Errorf("failed to write to pty: %s", err)
+			return
+		}
+	}
+}