Add PauseAfter option to shell provisioner

Closes #6540

provisioner/shell/provisioner.go

@@ -45,6 +45,11 @@ type Config struct {
 	// your command(s) are executed.
 	Vars []string `mapstructure:"environment_vars"`
 
+	// A duration of how long to pause after the provisioner
+	RawPauseAfter string `mapstructure:"pause_after"`
+
+	PauseAfter time.Duration
+
 	// Write the Vars to a file and source them from there rather than declaring
 	// inline
 	UseEnvVarFile bool `mapstructure:"use_env_var_file"`
@@ -189,6 +194,14 @@ func (p *Provisioner) Prepare(raws ...interface{}) error {
 		}
 	}
 
+	if p.config.RawPauseAfter != "" {
+		p.config.PauseAfter, err = time.ParseDuration(p.config.RawPauseAfter)
+		if err != nil {
+			errs = packer.MultiErrorAppend(
+				errs, fmt.Errorf("Failed parsing pause_after: %s", err))
+		}
+	}
+
 	if errs != nil && len(errs.Errors) > 0 {
 		return errs
 	}
@@ -371,7 +384,16 @@ func (p *Provisioner) Provision(ui packer.Ui, comm packer.Communicator) error {
 		}
 	}
 
+	if p.config.RawPauseAfter != "" {
+		ui.Say(fmt.Sprintf("Pausing %s after this provisioner...", p.config.PauseAfter))
+		select {
+		case <-time.After(p.config.PauseAfter):
+			return nil
+		}
+	}
+
 	return nil
+
 }
 
 func (p *Provisioner) cleanupRemoteFile(path string, comm packer.Communicator) error {

website/source/docs/provisioners/shell.html.md

@@ -115,6 +115,9 @@ Optional parameters:
     system reboot. Set this to a higher value if reboots take a longer amount
     of time.
 
+-   `pause_after` (string) - Wait the amount of time after provisioning a shell
+    script, this pause be taken if all previous steps were successful.
+
 ## Execute Command Example
 
 To many new users, the `execute_command` is puzzling. However, it provides an