Chef Commands

To provide new chef commands, you need to override the getCommands method of your plugin, and return command instances:

class MyPlugin(PieCrustPlugin):
    name = 'myplugin'

    def getCommands(self):
        return [
                MyNewCommand()]

To create a command class, inherit from the ChefCommand base class:

from piecrust.commands.base import ChefCommand

class MyNewCommand(ChefCommand):
    def __init__(self):
        super(MyNewCommand, self).__init__()
        self.name = 'foobar'
        self.description = "Does some foobar thing."

    def setupParser(self, parser, app):
        parser.add_argument('thing')

    def run(self, ctx):
        print("Doing %s" % ctx.args.thing)

• The name will be used for command line invocation, i.e. your new command will be invoked with chef foobar.
• The description will be used for help pages like chef --help.
• The setupParser method passes an argparse.ArgumentParser and a PieCrust application. You’re supposed to setup the syntax for your commend there.
• The run method is called when your command is executed. The ctx object contains a couple useful things, among others:
  • args is the namespace obtained from running parse_args. It has all the values of the arguments for your command.
  • app is the instance of the current PieCrust application.
  • For the other things, check-out piecrust.commands.base.CommandContext.