def get_common_instance_metadata(self):
        """
        Get project's common instance metadata.

        :return: CommonInstanceMetadata list extracted from REST response get
        project metadata.
        """
        self.logger.info(
            'Get commonInstanceMetadata for project {0}'.format(self.project))
        metadata = self.discovery.projects().get(
            project=self.project).execute()
        return metadata['commonInstanceMetadata']