Method SpawnShellServer

overlord/ghost.go:1340–1394

SpawnShellServer spawns a Shell server and forward input/output from/to the TCP socket.

(res *Response)

// SpawnShellServer spawns a Shell server and forward input/output from/to the
// TCP socket.
func (ghost *Ghost) SpawnShellServer(res *Response) error {
	log.Println("SpawnShellServer: started")

	var err error

	defer func() {
		ghost.quit = true
		if err != nil {
			if _, werr := ghost.Conn.Write([]byte(err.Error() + "\n")); werr != nil {
				log.Printf("Failed to write error to connection: %v", werr)
			}
		}
		ghost.Conn.Close()
		log.Println("SpawnShellServer: terminated")
	}()

	ghost.setupShellEnvironment()

	stopConn := make(chan struct{})

	cmd, stdin, err := ghost.setupShellCommand(stopConn)
	if err != nil {
		return err
	}

	if err = cmd.Start(); err != nil {
		return err
	}

	defer ghost.cleanupShellProcess(cmd)

	stdinOpen := true
	for {
		select {
		case buf := <-ghost.readChan:
			if stdinOpen {
				ghost.handleShellInput(stdin, buf)
			}
		case err := <-ghost.readErrChan:
			if err == io.EOF {
				if stdinOpen {
					log.Println("SpawnShellServer: input EOF, closing stdin")
					stdin.Close()
					stdinOpen = false
				}
				// Continue waiting for subprocess to finish
				continue
			}
			log.Printf("SpawnShellServer: %s\n", err)
			return err
		case <-stopConn:
			return nil
		}
	}
}

// InitiatefileOperation initiates a file operation.
// The operation could either be 'download' or 'upload'