builder/vmware: ability to not request a PTY for SSH [GH-270]

CHANGELOG.md

@@ -14,6 +14,8 @@ IMPROVEMENTS:
 
 * core: Output message when Ctrl-C received that we're cleaning up. [GH-338]
 * builder/amazon: Tagging now works with all amazon builder types.
+* builder/vmware: Option `ssh_skip_request_pty` for not requesting a PTY
+  for the SSH connection. [GH-270]
 * command/build: Machine-readable output now contains build errors, if any.
 * command/build: An "end" sentinel is outputted in machine-readable output
   for artifact listing so it is easier to know when it is over.

builder/vmware/builder.go

@@ -45,6 +45,7 @@ type config struct {
 	SSHUser           string            `mapstructure:"ssh_username"`
 	SSHPassword       string            `mapstructure:"ssh_password"`
 	SSHPort           uint              `mapstructure:"ssh_port"`
+	SSHSkipRequestPty bool              `mapstructure:"ssh_skip_request_pty"`
 	ToolsUploadFlavor string            `mapstructure:"tools_upload_flavor"`
 	ToolsUploadPath   string            `mapstructure:"tools_upload_path"`
 	VMXData           map[string]string `mapstructure:"vmx_data"`
@@ -342,6 +343,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			SSHAddress:     sshAddress,
 			SSHConfig:      sshConfig,
 			SSHWaitTimeout: b.config.sshWaitTimeout,
+			NoPty:          b.config.SSHSkipRequestPty,
 		},
 		&stepUploadTools{},
 		&common.StepProvision{},

common/step_connect_ssh.go

@@ -34,6 +34,9 @@ type StepConnectSSH struct {
 	// SSHWaitTimeout is the total timeout to wait for SSH to become available.
 	SSHWaitTimeout time.Duration
 
+	// NoPty, if true, will not request a Pty from the remote end.
+	NoPty bool
+
 	comm packer.Communicator
 }
 
@@ -128,6 +131,7 @@ func (s *StepConnectSSH) waitForSSH(state map[string]interface{}, cancel <-chan
 		config := &ssh.Config{
 			Connection: connFunc,
 			SSHConfig:  sshConfig,
+			NoPty:      s.NoPty,
 		}
 
 		log.Println("Attempting SSH connection...")

communicator/ssh/communicator.go

@@ -29,6 +29,9 @@ type Config struct {
 	// in use will be closed as part of the Close method, or in the
 	// case an error occurs.
 	Connection func() (net.Conn, error)
+
+	// NoPty, if true, will not request a pty from the remote end.
+	NoPty bool
 }
 
 // Creates a new packer.Communicator implementation over SSH. This takes
@@ -58,15 +61,17 @@ func (c *comm) Start(cmd *packer.RemoteCmd) (err error) {
 	session.Stdout = cmd.Stdout
 	session.Stderr = cmd.Stderr
 
-	// Request a PTY
-	termModes := ssh.TerminalModes{
-		ssh.ECHO:          0,     // do not echo
-		ssh.TTY_OP_ISPEED: 14400, // input speed = 14.4kbaud
-		ssh.TTY_OP_OSPEED: 14400, // output speed = 14.4kbaud
-	}
+	if !c.config.NoPty {
+		// Request a PTY
+		termModes := ssh.TerminalModes{
+			ssh.ECHO:          0,     // do not echo
+			ssh.TTY_OP_ISPEED: 14400, // input speed = 14.4kbaud
+			ssh.TTY_OP_OSPEED: 14400, // output speed = 14.4kbaud
+		}
 
-	if err = session.RequestPty("xterm", 80, 40, termModes); err != nil {
-		return
+		if err = session.RequestPty("xterm", 80, 40, termModes); err != nil {
+			return
+		}
 	}
 
 	log.Printf("starting remote command: %s", cmd.Command)

website/source/docs/builders/vmware.html.markdown

@@ -154,6 +154,10 @@ Optional:
 * `ssh_port` (int) - The port that SSH will listen on within the virtual
   machine. By default this is 22.
 
+* `ssh_skip_request_pty` (bool) - If true, a pty will not be requested as
+  part of the SSH connection. By default, this is "false", so a pty
+  _will_ be requested.
+
 * `ssh_wait_timeout` (string) - The duration to wait for SSH to become
   available. By default this is "20m", or 20 minutes. Note that this should
   be quite long since the timer begins as soon as the virtual machine is booted.