SwiftService ctor does not allow passing a Session object

[Andrew Berezovskiy]

In order to use SwiftService with an alternative auth mechanism (v3applicationcredential, also tracked in https://bugs.launchpad.net/python-keystoneclient/+bug/1843903). The particular error was reported in https://bugs.launchpad.net/python-swiftclient/+bug/1843901 but this bug report specifically relates to the fact that SwiftService is constructing a Connection itself, without allowing a Session object to be passed (which would be subsequently passed to the Connection ctor).

[Andrew Berezovskiy (an9rew)]

This is how I patched the SwiftService for the time being:

class SwiftConnectionService(SwiftService):
    def __init__(self, connection, options=None):
        """
        Override the manager before it's used
        """
        SwiftService.__init__(self, options=options)
        def create_connection():
            return connection
        # clean up the resources
        self.thread_manager.__exit__(None, None, None)
        self.thread_manager = MultiThreadingManager(
            create_connection,
            segment_threads=self._options['segment_threads'],
            object_dd_threads=self._options['object_dd_threads'],
            object_uu_threads=self._options['object_uu_threads'],
            container_threads=self._options['container_threads']
        )