Added eows (Exec Over WebSocket) package.

5 files changed, 374 insertions, 0 deletions

diff --git a/golib/eows/eows-in.go b/golib/eows/eows-in.go
new file mode 100644
index 0000000..1ecd2a1
--- /dev/null
+++ b/golib/eows/eows-in.go
@@ -0,0 +1,56 @@
+package eows
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"time"
+)
+
+type DoneChan struct {
+	status int
+	err    error
+}
+
+// cmdPumpStdin is in charge of receive characters and send them to stdin
+func (e *ExecOverWS) cmdPumpStdin(inw *os.File) {
+
+	done := make(chan DoneChan, 1)
+
+	if e.InputEvent != "" && e.InputCB != nil {
+
+		err := (*e.SocketIO).On(e.InputEvent, func(stdin string) {
+			in, err := e.InputCB(e, string(stdin))
+			if err != nil {
+				e.logDebug("Error stdin: %s", err.Error())
+				inw.Close()
+				return
+			}
+			if _, err := inw.Write([]byte(in)); err != nil {
+				e.logError("Error while writing to stdin: %s", err.Error())
+			}
+		})
+		if err != nil {
+			e.logError("Error stdin on event: %s", err.Error())
+		}
+	}
+
+	// Monitor process exit
+	go func() {
+		status := 0
+		sts, err := e.proc.Wait()
+		if !sts.Success() {
+			s := sts.Sys().(syscall.WaitStatus)
+			status = s.ExitStatus()
+		}
+		done <- DoneChan{status, err}
+	}()
+
+	// Wait cmd complete
+	select {
+	case dC := <-done:
+		e.ExitCB(e, dC.status, dC.err)
+	case <-time.After(time.Duration(e.CmdExecTimeout) * time.Second):
+		e.ExitCB(e, -999, fmt.Errorf("Exit Timeout for command ID %v", e.CmdID))
+	}
+}
diff --git a/golib/eows/eows-out.go b/golib/eows/eows-out.go
new file mode 100644
index 0000000..d624618
--- /dev/null
+++ b/golib/eows/eows-out.go
@@ -0,0 +1,47 @@
+package eows
+
+import (
+	"bufio"
+	"io"
+)
+
+// scanBlocks
+func scanBlocks(data []byte, atEOF bool) (advance int, token []byte, err error) {
+	if atEOF && len(data) == 0 {
+		return 0, nil, nil
+	}
+	return len(data), data, nil
+}
+
+// cmdPumpStdout is in charge to forward stdout in websocket
+func (e *ExecOverWS) cmdPumpStdout(r io.Reader, done chan struct{}) {
+
+	defer func() {
+	}()
+
+	sc := bufio.NewScanner(r)
+	sc.Split(scanBlocks)
+	for sc.Scan() {
+		e.OutputCB(e, sc.Text(), "")
+	}
+	if sc.Err() != nil {
+		e.logError("stdout scan:", sc.Err())
+	}
+
+	close(done)
+}
+
+// cmdPumpStderr is in charge to forward stderr in websocket
+func (e *ExecOverWS) cmdPumpStderr(r io.Reader) {
+
+	defer func() {
+	}()
+	sc := bufio.NewScanner(r)
+	sc.Split(scanBlocks)
+	for sc.Scan() {
+		e.OutputCB(e, "", sc.Text())
+	}
+	if sc.Err() != nil {
+		e.logError("stderr scan:", sc.Err())
+	}
+}
diff --git a/golib/eows/eows-signal.go b/golib/eows/eows-signal.go
new file mode 100644
index 0000000..5db5366
--- /dev/null
+++ b/golib/eows/eows-signal.go
@@ -0,0 +1,48 @@
+// +build !windows
+
+// Package eows is used to Execute commands Over WebSocket
+package eows
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+)
+
+// Signal sends a signal to the running command / process
+func (e *ExecOverWS) Signal(signal string) error {
+	var sig os.Signal
+	switch signal {
+	case "quit", "SIGQUIT":
+		sig = syscall.SIGQUIT
+	case "terminated", "SIGTERM":
+		sig = syscall.SIGTERM
+	case "interrupt", "SIGINT":
+		sig = syscall.SIGINT
+	case "aborted", "SIGABRT":
+		sig = syscall.SIGABRT
+	case "continued", "SIGCONT":
+		sig = syscall.SIGCONT
+	case "hangup", "SIGHUP":
+		sig = syscall.SIGHUP
+	case "killed", "SIGKILL":
+		sig = syscall.SIGKILL
+	case "stopped (signal)", "SIGSTOP":
+		sig = syscall.SIGSTOP
+	case "stopped", "SIGTSTP":
+		sig = syscall.SIGTSTP
+	case "user defined signal 1", "SIGUSR1":
+		sig = syscall.SIGUSR1
+	case "user defined signal 2", "SIGUSR2":
+		sig = syscall.SIGUSR2
+	default:
+		return fmt.Errorf("Unsupported signal")
+	}
+
+	if e.proc == nil {
+		return fmt.Errorf("Cannot retrieve process")
+	}
+
+	fmt.Printf("SEND signal %v to proc %v\n", sig, e.proc.Pid)
+	return e.proc.Signal(sig)
+}
diff --git a/golib/eows/eows-signal_windows.go b/golib/eows/eows-signal_windows.go
new file mode 100644
index 0000000..dff44f2
--- /dev/null
+++ b/golib/eows/eows-signal_windows.go
@@ -0,0 +1,47 @@
+package eows
+
+// +build windows
+
+import (
+	"fmt"
+)
+
+// Signal sends a signal to the running command / process
+func Signal(signal string) error {
+	panic("FIXME: Not implemented")
+	/*
+			var sig os.Signal
+			switch signal {
+			case "quit", "SIGQUIT":
+				sig = syscall.SIGQUIT
+			case "terminated", "SIGTERM":
+				sig = syscall.SIGTERM
+			case "interrupt", "SIGINT":
+				sig = syscall.SIGINT
+			case "aborted", "SIGABRT":
+				sig = syscall.SIGABRT
+			case "continued", "SIGCONT":
+				sig = syscall.SIGCONT
+			case "hangup", "SIGHUP":
+				sig = syscall.SIGHUP
+			case "killed", "SIGKILL":
+				sig = syscall.SIGKILL
+			case "stopped (signal)", "SIGSTOP":
+				sig = syscall.SIGSTOP
+			case "stopped", "SIGTSTP":
+				sig = syscall.SIGTSTP
+			case "user defined signal 1", "SIGUSR1":
+				sig = syscall.SIGUSR1
+			case "user defined signal 2", "SIGUSR2":
+				sig = syscall.SIGUSR2
+			default:
+				return fmt.Errorf("Unsupported signal")
+			}
+
+			if e.proc == nil {
+				return fmt.Errorf("Cannot retrieve process")
+			}
+		fmt.Printf("SEND signal %v to proc %v\n", sig, e.proc.Pid)
+		return e.proc.Signal(sig)
+	*/
+}
diff --git a/golib/eows/eows.go b/golib/eows/eows.go
new file mode 100644
index 0000000..6fc3550
--- /dev/null
+++ b/golib/eows/eows.go
@@ -0,0 +1,176 @@
+// Package eows is used to Execute commands Over WebSocket
+package eows
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/googollee/go-socket.io"
+)
+
+// OnInputCB is the function callback used to receive data
+type OnInputCB func(e *ExecOverWS, stdin string) (string, error)
+
+// EmitOutputCB is the function callback used to emit data
+type EmitOutputCB func(e *ExecOverWS, stdout, stderr string)
+
+// EmitExitCB is the function callback used to emit exit proc code
+type EmitExitCB func(e *ExecOverWS, code int, err error)
+
+// Inspired by :
+// https://github.com/gorilla/websocket/blob/master/examples/command/main.go
+
+// ExecOverWS .
+type ExecOverWS struct {
+	Cmd      string           // command name to execute
+	Args     []string         // command arguments
+	SocketIO *socketio.Socket // websocket
+	Sid      string           // websocket ID
+	CmdID    string           // command ID
+
+	// Optional fields
+	Env            []string                // command environment variables
+	CmdExecTimeout int                     // command execution time timeout
+	Log            *logrus.Logger          // logger (nil if disabled)
+	InputEvent     string                  // websocket input event name
+	InputCB        OnInputCB               // stdin callback
+	OutputCB       EmitOutputCB            // stdout/stderr callback
+	ExitCB         EmitExitCB              // exit proc callback
+	UserData       *map[string]interface{} // user data passed to callbacks
+
+	// Private fields
+	proc *os.Process
+}
+
+var cmdIDMap = make(map[string]*ExecOverWS)
+
+// New creates a new instace of eows
+func New(cmd string, args []string, so *socketio.Socket, soID, cmdID string) *ExecOverWS {
+
+	e := &ExecOverWS{
+		Cmd:            cmd,
+		Args:           args,
+		SocketIO:       so,
+		Sid:            soID,
+		CmdID:          cmdID,
+		CmdExecTimeout: -1, // default no timeout
+	}
+
+	cmdIDMap[cmdID] = e
+
+	return e
+}
+
+// GetEows gets ExecOverWS object from command ID
+func GetEows(cmdID string) *ExecOverWS {
+	if _, ok := cmdIDMap[cmdID]; !ok {
+		return nil
+	}
+	return cmdIDMap[cmdID]
+}
+
+// Start executes the command and redirect stdout/stderr into a WebSocket
+func (e *ExecOverWS) Start() error {
+	var err error
+	var outr, outw, errr, errw, inr, inw *os.File
+
+	bashArgs := []string{"/bin/bash", "-c", e.Cmd + " " + strings.Join(e.Args, " ")}
+
+	// no timeout == 1 year
+	if e.CmdExecTimeout == -1 {
+		e.CmdExecTimeout = 365 * 24 * 60 * 60
+	}
+
+	// Create pipes
+	outr, outw, err = os.Pipe()
+	if err != nil {
+		err = fmt.Errorf("Pipe stdout error: " + err.Error())
+		goto exitErr
+	}
+
+	errr, errw, err = os.Pipe()
+	if err != nil {
+		err = fmt.Errorf("Pipe stderr error: " + err.Error())
+		goto exitErr
+	}
+
+	inr, inw, err = os.Pipe()
+	if err != nil {
+		err = fmt.Errorf("Pipe stdin error: " + err.Error())
+		goto exitErr
+	}
+
+	e.proc, err = os.StartProcess("/bin/bash", bashArgs, &os.ProcAttr{
+		Files: []*os.File{inr, outw, errw},
+		Env:   append(os.Environ(), e.Env...),
+	})
+	if err != nil {
+		err = fmt.Errorf("Process start error: " + err.Error())
+		goto exitErr
+	}
+
+	go func() {
+		defer outr.Close()
+		defer outw.Close()
+		defer errr.Close()
+		defer errw.Close()
+		defer inr.Close()
+		defer inw.Close()
+
+		stdoutDone := make(chan struct{})
+		go e.cmdPumpStdout(outr, stdoutDone)
+		go e.cmdPumpStderr(errr)
+
+		// Blocking function that poll input or wait for end of process
+		e.cmdPumpStdin(inw)
+
+		// Some commands will exit when stdin is closed.
+		inw.Close()
+
+		defer outr.Close()
+
+		if status, err := e.proc.Wait(); err == nil {
+			// Other commands need a bonk on the head.
+			if !status.Exited() {
+				if err := e.proc.Signal(os.Interrupt); err != nil {
+					e.logError("Proc interrupt:", err)
+				}
+
+				select {
+				case <-stdoutDone:
+				case <-time.After(time.Second):
+					// A bigger bonk on the head.
+					if err := e.proc.Signal(os.Kill); err != nil {
+						e.logError("Proc term:", err)
+					}
+					<-stdoutDone
+				}
+			}
+		}
+
+		delete(cmdIDMap, e.CmdID)
+	}()
+
+	return nil
+
+exitErr:
+	for _, pf := range []*os.File{outr, outw, errr, errw, inr, inw} {
+		pf.Close()
+	}
+	return err
+}
+
+func (e *ExecOverWS) logDebug(format string, a ...interface{}) {
+	if e.Log != nil {
+		e.Log.Debugf(format, a)
+	}
+}
+
+func (e *ExecOverWS) logError(format string, a ...interface{}) {
+	if e.Log != nil {
+		e.Log.Errorf(format, a)
+	}
+}