packer-cn/packer/command.go

package packer

// A command is a runnable sub-command of the `packer` application.
// When `packer` is called with the proper subcommand, this will be
// called.
//
// The mapping of command names to command interfaces is in the
// Environment struct.
type Command interface {
	// Help should return long-form help text that includes the command-line
	// usage, a brief few sentences explaining the function of the command,
	// and the complete list of flags the command accepts.
	Help() string

	// Run should run the actual command with the given environmet and
	// command-line arguments. It should return the exit status when it is
	// finished.
	Run(env Environment, args []string) int

	// Synopsis should return a one-line, short synopsis of the command.
	// This should be less than 50 characters ideally.
	Synopsis() string
}