【修改】k8s 配置

apps/devops/services/k8s/terminal/terminal.go

@@ -0,0 +1,297 @@
+package terminal
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"github.com/gin-gonic/gin"
+	"io"
+	"log"
+	"net/http"
+	"sync"
+
+	"gopkg.in/igm/sockjs-go.v2/sockjs"
+	v1 "k8s.io/api/core/v1"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/kubernetes/scheme"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/remotecommand"
+)
+
+const END_OF_TRANSMISSION = "\u0004"
+
+// PtyHandler is what remotecommand expects from a pty
+type PtyHandler interface {
+	io.Reader
+	io.Writer
+	remotecommand.TerminalSizeQueue
+}
+
+// TerminalSession implements PtyHandler (using a SockJS connection)
+type TerminalSession struct {
+	id            string
+	bound         chan error
+	sockJSSession sockjs.Session
+	sizeChan      chan remotecommand.TerminalSize
+	doneChan      chan struct{}
+}
+
+// TerminalMessage is the messaging protocol between ShellController and TerminalSession.
+//
+// OP      DIRECTION  FIELD(S) USED  DESCRIPTION
+// ---------------------------------------------------------------------
+// bind    fe->be     SessionID      Id sent back from TerminalResponse
+// stdin   fe->be     Data           Keystrokes/paste buffer
+// resize  fe->be     Rows, Cols     New terminal size
+// stdout  be->fe     Data           Output from the process
+// toast   be->fe     Data           OOB message to be shown to the user
+type TerminalMessage struct {
+	Op, Data, SessionID string
+	Rows, Cols          uint16
+}
+
+// TerminalSize handles pty->process resize events
+// Called in a loop from remotecommand as long as the process is running
+func (t TerminalSession) Next() *remotecommand.TerminalSize {
+	select {
+	case size := <-t.sizeChan:
+		return &size
+	case <-t.doneChan:
+		return nil
+	}
+}
+
+// Read handles pty->process messages (stdin, resize)
+// Called in a loop from remotecommand as long as the process is running
+func (t TerminalSession) Read(p []byte) (int, error) {
+	m, err := t.sockJSSession.Recv()
+	if err != nil {
+		// Send terminated signal to process to avoid resource leak
+		return copy(p, END_OF_TRANSMISSION), err
+	}
+
+	var msg TerminalMessage
+	if err := json.Unmarshal([]byte(m), &msg); err != nil {
+		return copy(p, END_OF_TRANSMISSION), err
+	}
+
+	switch msg.Op {
+	case "stdin":
+		return copy(p, msg.Data), nil
+	case "resize":
+		t.sizeChan <- remotecommand.TerminalSize{Width: msg.Cols, Height: msg.Rows}
+		return 0, nil
+	default:
+		return copy(p, END_OF_TRANSMISSION), fmt.Errorf("unknown message type '%s'", msg.Op)
+	}
+}
+
+// Write handles process->pty stdout
+// Called from remotecommand whenever there is any output
+func (t TerminalSession) Write(p []byte) (int, error) {
+	msg, err := json.Marshal(TerminalMessage{
+		Op:   "stdout",
+		Data: string(p),
+	})
+	if err != nil {
+		return 0, err
+	}
+
+	if err = t.sockJSSession.Send(string(msg)); err != nil {
+		return 0, err
+	}
+	return len(p), nil
+}
+
+// Toast can be used to send the user any OOB messages
+// hterm puts these in the center of the terminal
+func (t TerminalSession) Toast(p string) error {
+	msg, err := json.Marshal(TerminalMessage{
+		Op:   "toast",
+		Data: p,
+	})
+	if err != nil {
+		return err
+	}
+
+	if err = t.sockJSSession.Send(string(msg)); err != nil {
+		return err
+	}
+	return nil
+}
+
+// SessionMap stores a map of all TerminalSession objects and a lock to avoid concurrent conflict
+type SessionMap struct {
+	Sessions map[string]TerminalSession
+	Lock     sync.RWMutex
+}
+
+// Get return a given terminalSession by sessionId
+func (sm *SessionMap) Get(sessionId string) TerminalSession {
+	sm.Lock.RLock()
+	defer sm.Lock.RUnlock()
+	return sm.Sessions[sessionId]
+}
+
+// Set store a TerminalSession to SessionMap
+func (sm *SessionMap) Set(sessionId string, session TerminalSession) {
+	sm.Lock.Lock()
+	defer sm.Lock.Unlock()
+	sm.Sessions[sessionId] = session
+}
+
+// Close shuts down the SockJS connection and sends the status code and reason to the client
+// Can happen if the process exits or if there is an error starting up the process
+// For now the status code is unused and reason is shown to the user (unless "")
+func (sm *SessionMap) Close(sessionId string, status uint32, reason string) {
+	sm.Lock.Lock()
+	defer sm.Lock.Unlock()
+	err := sm.Sessions[sessionId].sockJSSession.Close(status, reason)
+	if err != nil {
+		log.Println(err)
+	}
+
+	delete(sm.Sessions, sessionId)
+}
+
+var terminalSessions = SessionMap{Sessions: make(map[string]TerminalSession)}
+
+// handleTerminalSession is Called by net/http for any new /api/sockjs connections
+func handleTerminalSession(session sockjs.Session) {
+	var (
+		buf             string
+		err             error
+		msg             TerminalMessage
+		terminalSession TerminalSession
+	)
+
+	if buf, err = session.Recv(); err != nil {
+		log.Printf("handleTerminalSession: can't Recv: %v", err)
+		return
+	}
+
+	if err = json.Unmarshal([]byte(buf), &msg); err != nil {
+		log.Printf("handleTerminalSession: can't UnMarshal (%v): %s", err, buf)
+		return
+	}
+
+	if msg.Op != "bind" {
+		log.Printf("handleTerminalSession: expected 'bind' message, got: %s", buf)
+		return
+	}
+
+	if terminalSession = terminalSessions.Get(msg.SessionID); terminalSession.id == "" {
+		log.Printf("handleTerminalSession: can't find session '%s'", msg.SessionID)
+		return
+	}
+
+	terminalSession.sockJSSession = session
+	terminalSessions.Set(msg.SessionID, terminalSession)
+	terminalSession.bound <- nil
+}
+
+// CreateAttachHandler is called from main for /api/sockjs
+func CreateAttachHandler(path string) http.Handler {
+	return sockjs.NewHandler(path, sockjs.DefaultOptions, handleTerminalSession)
+}
+
+// startProcess is called by handleAttach
+// Executed cmd in the container specified in request and connects it up with the ptyHandler (a session)
+func startProcess(k8sClient kubernetes.Interface, cfg *rest.Config, request *gin.Context, cmd []string, ptyHandler PtyHandler) error {
+	namespace := request.Query("namespace")
+	podName := request.Query("pod")
+	containerName := request.Query("container")
+
+	req := k8sClient.CoreV1().RESTClient().Post().
+		Resource("pods").
+		Name(podName).
+		Namespace(namespace).
+		SubResource("exec")
+
+	req.VersionedParams(&v1.PodExecOptions{
+		Container: containerName,
+		Command:   cmd,
+		Stdin:     true,
+		Stdout:    true,
+		Stderr:    true,
+		TTY:       true,
+	}, scheme.ParameterCodec)
+
+	exec, err := remotecommand.NewSPDYExecutor(cfg, "POST", req.URL())
+	if err != nil {
+		return err
+	}
+
+	err = exec.Stream(remotecommand.StreamOptions{
+		Stdin:             ptyHandler,
+		Stdout:            ptyHandler,
+		Stderr:            ptyHandler,
+		TerminalSizeQueue: ptyHandler,
+		Tty:               true,
+	})
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// genTerminalSessionId generates a random session ID string. The format is not really interesting.
+// This ID is used to identify the session when the client opens the SockJS connection.
+// Not the same as the SockJS session id! We can't use that as that is generated
+// on the client side and we don't have it yet at this point.
+func genTerminalSessionId() (string, error) {
+	bytes := make([]byte, 16)
+	if _, err := rand.Read(bytes); err != nil {
+		return "", err
+	}
+	id := make([]byte, hex.EncodedLen(len(bytes)))
+	hex.Encode(id, bytes)
+	return string(id), nil
+}
+
+// isValidShell checks if the shell is an allowed one
+func isValidShell(validShells []string, shell string) bool {
+	for _, validShell := range validShells {
+		if validShell == shell {
+			return true
+		}
+	}
+	return false
+}
+
+// WaitForTerminal is called from apihandler.handleAttach as a goroutine
+// Waits for the SockJS connection to be opened by the client the session to be bound in handleTerminalSession
+func WaitForTerminal(k8sClient kubernetes.Interface, cfg *rest.Config, request *gin.Context, sessionId string) {
+	shell := request.Query("shell")
+
+	select {
+	case <-terminalSessions.Get(sessionId).bound:
+		close(terminalSessions.Get(sessionId).bound)
+
+		var err error
+		validShells := []string{"bash", "sh", "powershell", "cmd"}
+
+		if isValidShell(validShells, shell) {
+			cmd := []string{shell}
+			err = startProcess(k8sClient, cfg, request, cmd, terminalSessions.Get(sessionId))
+		} else {
+			// No shell given or it was not valid: try some shells until one succeeds or all fail
+			// FIXME: if the first shell fails then the first keyboard event is lost
+			for _, testShell := range validShells {
+				cmd := []string{testShell}
+				if err = startProcess(k8sClient, cfg, request, cmd, terminalSessions.Get(sessionId)); err == nil {
+					break
+				}
+			}
+		}
+
+		if err != nil {
+			terminalSessions.Close(sessionId, 2, err.Error())
+			return
+		}
+
+		terminalSessions.Close(sessionId, 1, "Process exited")
+	}
+}