using-roles.rst

Using Roles in my Roles

As you may have noticed, provy provides a special syntax for using other roles in your role. Say we need to use the AptitudeRole in our role. This is how we'd do it:

class MyRole(Role):
    def provision(self):
        with self.using(AptitudeRole) as role:
            # do something with role
            role.ensure_package_installed('some-package')

The using method of the Role class is a special way of using other roles. The reason for using it is that it maintains context and the provy lifecycle (more on both later).

If you just want to provision another role in your role, you can use:

class MyRole(Role):
    def provision(self):
        self.provision_role(TornadoRole)

The provision_role method does exactly the same as the using method, except it does not enter a with block. This should be used when you don't wnat to call anything in the role, instead just have it provisioned.