Golang ssh.New函數代碼示例

func (d *ESX5Driver) connect() error {
	address := fmt.Sprintf("%s:%d", d.Host, d.Port)

	auth := []gossh.AuthMethod{
		gossh.Password(d.Password),
		gossh.KeyboardInteractive(
			ssh.PasswordKeyboardInteractive(d.Password)),
	}

	// TODO(dougm) KeyPath support
	sshConfig := &ssh.Config{
		Connection: ssh.ConnectFunc("tcp", address),
		SSHConfig: &gossh.ClientConfig{
			User: d.Username,
			Auth: auth,
		},
		NoPty: true,
	}

	comm, err := ssh.New(address, sshConfig)
	if err != nil {
		return err
	}

	d.comm = comm
	return nil
}

func (d *ESX5Driver) connect() error {
	address := fmt.Sprintf("%s:%d", d.Host, d.Port)

	auth := []gossh.AuthMethod{
		gossh.Password(d.Password),
		gossh.KeyboardInteractive(
			ssh.PasswordKeyboardInteractive(d.Password)),
	}

	if d.PrivateKey != "" {
		signer, err := commonssh.FileSigner(d.PrivateKey)
		if err != nil {
			return err
		}

		auth = append(auth, gossh.PublicKeys(signer))
	}

	sshConfig := &ssh.Config{
		Connection: ssh.ConnectFunc("tcp", address),
		SSHConfig: &gossh.ClientConfig{
			User: d.Username,
			Auth: auth,
		},
	}

	comm, err := ssh.New(address, sshConfig)
	if err != nil {
		return err
	}

	d.comm = comm
	return nil
}

func (p *PostProcessor) connect() error {
	address := fmt.Sprintf("%s:%d", p.config.Host, p.config.SshPort)

	auth := []gossh.AuthMethod{
		gossh.Password(p.config.Password),
		gossh.KeyboardInteractive(
			ssh.PasswordKeyboardInteractive(p.config.Password)),
	}

	// TODO(dougm) KeyPath support
	sshConfig := &ssh.Config{
		Connection: ssh.ConnectFunc("tcp", address),
		SSHConfig: &gossh.ClientConfig{
			User: p.config.Username,
			Auth: auth,
		},
	}

	comm, err := ssh.New(address, sshConfig)
	if err != nil {
		return err
	}

	p.comm = comm
	return nil
}

func (s *StepConnectSSH) waitForSSH(state multistep.StateBag, cancel <-chan struct{}) (packer.Communicator, error) {
	// Determine if we're using a bastion host, and if so, retrieve
	// that configuration. This configuration doesn't change so we
	// do this one before entering the retry loop.
	var bProto, bAddr string
	var bConf *gossh.ClientConfig
	if s.Config.SSHBastionHost != "" {
		// The protocol is hardcoded for now, but may be configurable one day
		bProto = "tcp"
		bAddr = fmt.Sprintf(
			"%s:%d", s.Config.SSHBastionHost, s.Config.SSHBastionPort)

		conf, err := sshBastionConfig(s.Config)
		if err != nil {
			return nil, fmt.Errorf("Error configuring bastion: %s", err)
		}
		bConf = conf
	}

	handshakeAttempts := 0

	var comm packer.Communicator
	first := true
	for {
		// Don't check for cancel or wait on first iteration
		if !first {
			select {
			case <-cancel:
				log.Println("[DEBUG] SSH wait cancelled. Exiting loop.")
				return nil, errors.New("SSH wait cancelled")
			case <-time.After(5 * time.Second):
			}
		}
		first = false

		// First we request the TCP connection information
		host, err := s.Host(state)
		if err != nil {
			log.Printf("[DEBUG] Error getting SSH address: %s", err)
			continue
		}
		port := s.Config.SSHPort
		if s.SSHPort != nil {
			port, err = s.SSHPort(state)
			if err != nil {
				log.Printf("[DEBUG] Error getting SSH port: %s", err)
				continue
			}
		}

		// Retrieve the SSH configuration
		sshConfig, err := s.SSHConfig(state)
		if err != nil {
			log.Printf("[DEBUG] Error getting SSH config: %s", err)
			continue
		}

		// Attempt to connect to SSH port
		var connFunc func() (net.Conn, error)
		address := fmt.Sprintf("%s:%d", host, port)
		if bAddr != "" {
			// We're using a bastion host, so use the bastion connfunc
			connFunc = ssh.BastionConnectFunc(
				bProto, bAddr, bConf, "tcp", address)
		} else {
			// No bastion host, connect directly
			connFunc = ssh.ConnectFunc("tcp", address)
		}

		nc, err := connFunc()
		if err != nil {
			log.Printf("[DEBUG] TCP connection to SSH ip/port failed: %s", err)
			continue
		}
		nc.Close()

		// Then we attempt to connect via SSH
		config := &ssh.Config{
			Connection:   connFunc,
			SSHConfig:    sshConfig,
			Pty:          s.Config.SSHPty,
			DisableAgent: s.Config.SSHDisableAgent,
		}

		log.Println("[INFO] Attempting SSH connection...")
		comm, err = ssh.New(address, config)
		if err != nil {
			log.Printf("[DEBUG] SSH handshake err: %s", err)

			// Only count this as an attempt if we were able to attempt
			// to authenticate. Note this is very brittle since it depends
			// on the string of the error... but I don't see any other way.
			if strings.Contains(err.Error(), "authenticate") {
				log.Printf(
					"[DEBUG] Detected authentication error. Increasing handshake attempts.")
				handshakeAttempts += 1
			}

			if handshakeAttempts < s.Config.SSHHandshakeAttempts {
				// Try to connect via SSH a handful of times. We sleep here
//.........這裏部分代碼省略.........

func (s *stepConnectSSH) Run(state map[string]interface{}) multistep.StepAction {
	config := state["config"].(config)
	privateKey := state["privateKey"].(string)
	ui := state["ui"].(packer.Ui)
	ipAddress := state["droplet_ip"]

	// Build the keyring for authentication. This stores the private key
	// we'll use to authenticate.
	keyring := &ssh.SimpleKeychain{}
	err := keyring.AddPEMKey(privateKey)
	if err != nil {
		err := fmt.Errorf("Error setting up SSH config: %s", err)
		state["error"] = err
		ui.Error(err.Error())
		return multistep.ActionHalt
	}

	connFunc := ssh.ConnectFunc(
		"tcp",
		fmt.Sprintf("%s:%d", ipAddress, config.SSHPort),
		5*time.Minute)

	// Build the actual SSH client configuration
	sshConfig := &ssh.Config{
		Connection: connFunc,
		SSHConfig: &gossh.ClientConfig{
			User: config.SSHUsername,
			Auth: []gossh.ClientAuth{
				gossh.ClientAuthKeyring(keyring),
			},
		},
	}

	// Start trying to connect to SSH
	connected := make(chan error, 1)
	connectQuit := make(chan bool, 1)
	defer func() {
		connectQuit <- true
	}()

	var comm packer.Communicator
	go func() {
		ui.Say("Connecting to the droplet via SSH...")
		attempts := 0
		handshakeAttempts := 0
		for {
			select {
			case <-connectQuit:
				return
			default:
			}

			// A brief sleep so we're not being overly zealous attempting
			// to connect to the instance.
			time.Sleep(500 * time.Millisecond)

			attempts += 1
			nc, err := connFunc()
			if err != nil {
				continue
			}
			nc.Close()

			log.Println("TCP connection made. Attempting SSH handshake.")
			comm, err = ssh.New(sshConfig)
			if err == nil {
				log.Println("Connected to SSH!")
				break
			}

			handshakeAttempts += 1
			log.Printf("SSH handshake error: %s", err)

			if handshakeAttempts > 5 {
				connected <- err
				return
			}
		}

		connected <- nil
	}()

	log.Printf("Waiting up to %s for SSH connection", config.sshTimeout)
	timeout := time.After(config.sshTimeout)

ConnectWaitLoop:
	for {
		select {
		case err := <-connected:
			if err != nil {
				err := fmt.Errorf("Error connecting to SSH: %s", err)
				state["error"] = err
				ui.Error(err.Error())
				return multistep.ActionHalt
			}

			// We connected. Just break the loop.
			break ConnectWaitLoop
		case <-timeout:
			err := errors.New("Timeout waiting for SSH to become available.")
//.........這裏部分代碼省略.........

// This blocks until SSH becomes available, and sends the communicator
// on the given channel.
func (s *stepWaitForSSH) waitForSSH(state map[string]interface{}) (packer.Communicator, error) {
	config := state["config"].(*config)
	ui := state["ui"].(packer.Ui)
	sshHostPort := state["sshHostPort"].(uint)

	ui.Say("Waiting for SSH to become available...")
	var comm packer.Communicator
	var nc net.Conn
	for {
		if nc != nil {
			nc.Close()
		}

		time.Sleep(5 * time.Second)

		if s.cancel {
			log.Println("SSH wait cancelled. Exiting loop.")
			return nil, errors.New("SSH wait cancelled")
		}

		// Attempt to connect to SSH port
		nc, err := net.Dial("tcp", fmt.Sprintf("127.0.0.1:%d", sshHostPort))
		if err != nil {
			log.Printf("TCP connection to SSH ip/port failed: %s", err)
			continue
		}

		// Then we attempt to connect via SSH
		sshConfig := &gossh.ClientConfig{
			User: config.SSHUser,
			Auth: []gossh.ClientAuth{
				gossh.ClientAuthPassword(ssh.Password(config.SSHPassword)),
				gossh.ClientAuthKeyboardInteractive(
					ssh.PasswordKeyboardInteractive(config.SSHPassword)),
			},
		}

		sshConnectSuccess := make(chan bool, 1)
		go func() {
			comm, err = ssh.New(nc, sshConfig)
			if err != nil {
				log.Printf("SSH connection fail: %s", err)
				sshConnectSuccess <- false
				return
			}

			sshConnectSuccess <- true
		}()

		select {
		case success := <-sshConnectSuccess:
			if !success {
				continue
			}
		case <-time.After(5 * time.Second):
			log.Printf("SSH handshake timeout. Trying again.")
			continue
		}

		ui.Say("Connected via SSH!")
		break
	}

	// Store the connection so we can close it later
	s.conn = nc
	return comm, nil
}

func (s *StepConnectSSH) waitForSSH(state multistep.StateBag, cancel <-chan struct{}) (packer.Communicator, error) {
	handshakeAttempts := 0

	var comm packer.Communicator
	for {
		select {
		case <-cancel:
			log.Println("SSH wait cancelled. Exiting loop.")
			return nil, errors.New("SSH wait cancelled")
		case <-time.After(5 * time.Second):
		}

		// First we request the TCP connection information
		address, err := s.SSHAddress(state)
		if err != nil {
			log.Printf("Error getting SSH address: %s", err)
			continue
		}

		// Retrieve the SSH configuration
		sshConfig, err := s.SSHConfig(state)
		if err != nil {
			log.Printf("Error getting SSH config: %s", err)
			continue
		}

		// Attempt to connect to SSH port
		connFunc := ssh.ConnectFunc("tcp", address)
		nc, err := connFunc()
		if err != nil {
			log.Printf("TCP connection to SSH ip/port failed: %s", err)
			continue
		}
		nc.Close()

		// Then we attempt to connect via SSH
		config := &ssh.Config{
			Connection: connFunc,
			SSHConfig:  sshConfig,
			NoPty:      s.NoPty,
		}

		log.Println("Attempting SSH connection...")
		comm, err = ssh.New(config)
		if err != nil {
			log.Printf("SSH handshake err: %s", err)

			// Only count this as an attempt if we were able to attempt
			// to authenticate. Note this is very brittle since it depends
			// on the string of the error... but I don't see any other way.
			if strings.Contains(err.Error(), "authenticate") {
				log.Printf("Detected authentication error. Increasing handshake attempts.")
				handshakeAttempts += 1
			}

			if handshakeAttempts < 10 {
				// Try to connect via SSH a handful of times
				continue
			}

			return nil, err
		}

		break
	}

	return comm, nil
}

// This blocks until SSH becomes available, and sends the communicator
// on the given channel.
func (s *stepConnectSSH) waitForSSH(state map[string]interface{}) (packer.Communicator, error) {
	config := state["config"].(config)
	instance := state["instance"].(*ec2.Instance)
	privateKey := state["privateKey"].(string)
	ui := state["ui"].(packer.Ui)

	// Build the keyring for authentication. This stores the private key
	// we'll use to authenticate.
	keyring := &ssh.SimpleKeychain{}
	err := keyring.AddPEMKey(privateKey)
	if err != nil {
		return nil, fmt.Errorf("Error setting up SSH config: %s", err)
	}

	// Create the function that will be used to create the connection
	connFunc := ssh.ConnectFunc(
		"tcp", fmt.Sprintf("%s:%d", instance.DNSName, config.SSHPort), 5*time.Minute)

	ui.Say("Waiting for SSH to become available...")
	var comm packer.Communicator
	for {
		time.Sleep(5 * time.Second)

		if s.cancel {
			log.Println("SSH wait cancelled. Exiting loop.")
			return nil, errors.New("SSH wait cancelled")
		}

		// First just attempt a normal TCP connection that we close right
		// away. We just test this in order to wait for the TCP port to be ready.
		nc, err := connFunc()
		if err != nil {
			log.Printf("TCP connection to SSH ip/port failed: %s", err)
			continue
		}
		nc.Close()

		// Build the configuration to connect to SSH
		config := &ssh.Config{
			Connection: connFunc,
			SSHConfig: &gossh.ClientConfig{
				User: config.SSHUsername,
				Auth: []gossh.ClientAuth{
					gossh.ClientAuthKeyring(keyring),
				},
			},
		}

		sshConnectSuccess := make(chan bool, 1)
		go func() {
			comm, err = ssh.New(config)
			if err != nil {
				log.Printf("SSH connection fail: %s", err)
				sshConnectSuccess <- false
				return
			}

			sshConnectSuccess <- true
		}()

		select {
		case success := <-sshConnectSuccess:
			if !success {
				continue
			}
		case <-time.After(5 * time.Second):
			log.Printf("SSH handshake timeout. Trying again.")
			continue
		}

		ui.Say("Connected via SSH!")
		break
	}

	return comm, nil
}

// This blocks until SSH becomes available, and sends the communicator
// on the given channel.
func (s *stepWaitForSSH) waitForSSH(state map[string]interface{}) (packer.Communicator, error) {
	config := state["config"].(*config)
	ui := state["ui"].(packer.Ui)
	vmxPath := state["vmx_path"].(string)

	handshakeAttempts := 0

	ui.Say("Waiting for SSH to become available...")
	var comm packer.Communicator
	for {
		time.Sleep(5 * time.Second)

		if s.cancel {
			log.Println("SSH wait cancelled. Exiting loop.")
			return nil, errors.New("SSH wait cancelled")
		}

		// First we wait for the IP to become available...
		log.Println("Lookup up IP information...")
		ipLookup, err := s.dhcpLeaseLookup(vmxPath)
		if err != nil {
			log.Printf("Can't lookup via DHCP lease: %s", err)
		}

		ip, err := ipLookup.GuestIP()
		if err != nil {
			log.Printf("IP lookup failed: %s", err)
			continue
		}

		log.Printf("Detected IP: %s", ip)

		// Attempt to connect to SSH port
		connFunc := ssh.ConnectFunc(
			"tcp", fmt.Sprintf("%s:%d", ip, config.SSHPort), 5*time.Minute)
		nc, err := connFunc()
		if err != nil {
			log.Printf("TCP connection to SSH ip/port failed: %s", err)
			continue
		}
		nc.Close()

		// Then we attempt to connect via SSH
		config := &ssh.Config{
			Connection: connFunc,
			SSHConfig: &gossh.ClientConfig{
				User: config.SSHUser,
				Auth: []gossh.ClientAuth{
					gossh.ClientAuthPassword(ssh.Password(config.SSHPassword)),
					gossh.ClientAuthKeyboardInteractive(
						ssh.PasswordKeyboardInteractive(config.SSHPassword)),
				},
			},
		}

		comm, err = ssh.New(config)
		if err != nil {
			log.Printf("SSH handshake err: %s", err)

			handshakeAttempts += 1
			if handshakeAttempts < 10 {
				// Try to connect via SSH a handful of times
				continue
			}

			return nil, err
		}

		ui.Say("Connected via SSH!")
		break
	}

	return comm, nil
}

// This blocks until SSH becomes available, and sends the communicator
// on the given channel.
func (s *stepConnectSSH) waitForSSH(state map[string]interface{}) (packer.Communicator, error) {
	config := state["config"].(config)
	instance := state["instance"].(*ec2.Instance)
	privateKey := state["privateKey"].(string)
	ui := state["ui"].(packer.Ui)

	// Build the keyring for authentication. This stores the private key
	// we'll use to authenticate.
	keyring := &ssh.SimpleKeychain{}
	err := keyring.AddPEMKey(privateKey)
	if err != nil {
		return nil, fmt.Errorf("Error setting up SSH config: %s", err)
	}

	ui.Say("Waiting for SSH to become available...")
	var comm packer.Communicator
	var nc net.Conn
	for {
		if nc != nil {
			nc.Close()
		}

		time.Sleep(5 * time.Second)

		if s.cancel {
			log.Println("SSH wait cancelled. Exiting loop.")
			return nil, errors.New("SSH wait cancelled")
		}

		// Attempt to connect to SSH port
		log.Printf(
			"Opening TCP conn for SSH to %s:%d",
			instance.DNSName, config.SSHPort)
		nc, err := net.Dial("tcp",
			fmt.Sprintf("%s:%d", instance.DNSName, config.SSHPort))
		if err != nil {
			log.Printf("TCP connection to SSH ip/port failed: %s", err)
			continue
		}

		// Build the actual SSH client configuration
		sshConfig := &gossh.ClientConfig{
			User: config.SSHUsername,
			Auth: []gossh.ClientAuth{
				gossh.ClientAuthKeyring(keyring),
			},
		}

		sshConnectSuccess := make(chan bool, 1)
		go func() {
			comm, err = ssh.New(nc, sshConfig)
			if err != nil {
				log.Printf("SSH connection fail: %s", err)
				sshConnectSuccess <- false
				return
			}

			sshConnectSuccess <- true
		}()

		select {
		case success := <-sshConnectSuccess:
			if !success {
				continue
			}
		case <-time.After(5 * time.Second):
			log.Printf("SSH handshake timeout. Trying again.")
			continue
		}

		ui.Say("Connected via SSH!")
		break
	}

	// Store the connection so we can close it later
	s.conn = nc
	return comm, nil
}

func (s *stepConnectSSH) Run(state map[string]interface{}) multistep.StepAction {
	config := state["config"].(config)
	instance := state["instance"].(*ec2.Instance)
	privateKey := state["privateKey"].(string)
	ui := state["ui"].(packer.Ui)

	// Build the keyring for authentication. This stores the private key
	// we'll use to authenticate.
	keyring := &ssh.SimpleKeychain{}
	err := keyring.AddPEMKey(privateKey)
	if err != nil {
		err := fmt.Errorf("Error setting up SSH config: %s", err)
		state["error"] = err
		ui.Error(err.Error())
		return multistep.ActionHalt
	}

	// Build the actual SSH client configuration
	sshConfig := &gossh.ClientConfig{
		User: config.SSHUsername,
		Auth: []gossh.ClientAuth{
			gossh.ClientAuthKeyring(keyring),
		},
	}

	// Start trying to connect to SSH
	connected := make(chan bool, 1)
	connectQuit := make(chan bool, 1)
	defer func() {
		connectQuit <- true
	}()

	go func() {
		var err error

		ui.Say("Connecting to the instance via SSH...")
		attempts := 0
		for {
			select {
			case <-connectQuit:
				return
			default:
			}

			attempts += 1
			log.Printf(
				"Opening TCP conn for SSH to %s:%d (attempt %d)",
				instance.DNSName, config.SSHPort, attempts)
			s.conn, err = net.Dial("tcp", fmt.Sprintf("%s:%d", instance.DNSName, config.SSHPort))
			if err == nil {
				break
			}

			// A brief sleep so we're not being overly zealous attempting
			// to connect to the instance.
			time.Sleep(500 * time.Millisecond)
		}

		connected <- true
	}()

	log.Printf("Waiting up to %s for SSH connection", config.SSHTimeout)
	timeout := time.After(config.SSHTimeout)

ConnectWaitLoop:
	for {
		select {
		case <-connected:
			// We connected. Just break the loop.
			break ConnectWaitLoop
		case <-timeout:
			err := errors.New("Timeout waiting for SSH to become available.")
			state["error"] = err
			ui.Error(err.Error())
			return multistep.ActionHalt
		case <-time.After(1 * time.Second):
			if _, ok := state[multistep.StateCancelled]; ok {
				log.Println("Interrupt detected, quitting waiting for SSH.")
				return multistep.ActionHalt
			}
		}
	}

	var comm packer.Communicator
	if err == nil {
		comm, err = ssh.New(s.conn, sshConfig)
	}

	if err != nil {
		err := fmt.Errorf("Error connecting to SSH: %s", err)
		state["error"] = err
		ui.Error(err.Error())
		return multistep.ActionHalt
	}

	// Set the communicator on the state bag so it can be used later
	state["communicator"] = comm

	return multistep.ActionContinue
}