def _check_provider_exists(provider_id):
"""Check whether a provider exists or not.
"""
provider = Provider.fetch(provider_id)
if provider:
raise _errors.ProviderError("Provider (%s) already exists." %
(provider_id, ))
def _check_machines_exist(provider):
"""Check whether there is a machine associated to a provider or not.
"""
for machine in Machine.machines(provider.provider_id):
raise _errors.ProviderError(
"There are machines associated to the provider (%s)." %
(provider.provider_id, ))
def _retrieve_provider(provider_id):
"""Return a provider object from an id.
"""
provider = Provider.fetch(provider_id)
if not provider:
raise _errors.ProviderError("Provider (%s) does not exist." %
(provider_id, ))
return provider