From: Matthijs Kooijman Date: Mon, 17 May 2010 17:04:28 +0000 (+0200) Subject: main: Add action loading and running infrastructure. X-Git-Url: https://git.stderr.nl/gitweb?p=matthijs%2Fprojects%2Fbackupninja.git;a=commitdiff_plain;h=c9514724e6fad55405d92f3931056d5f69cfa4f4 main: Add action loading and running infrastructure. --- diff --git a/src/lib/backupninja/action.py b/src/lib/backupninja/action.py new file mode 100644 index 0000000..3f57a18 --- /dev/null +++ b/src/lib/backupninja/action.py @@ -0,0 +1,61 @@ +# -*- mode: python; sh-basic-offset: 4; indent-tabs-mode: nil; -*- +# vim: set filetype=python sw=4 sts=4 expandtab autoindent: +# +# Backupninja python reimplementation, based on original backupninja program +# by riseup.net. +# Copyright (C) 2010 Matthijs Kooijman +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License along +# with this program; if not, write to the Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +""" Running backup actions """ + +from backupninja import config +from backupninja import handlers + +def run_all_actions(opts, global_config): + """ + Run all defined actions. + + opts are the parsed commandline options, global_config is the parsed + global configuration. + """ + actions = config.list_actions(opts) + + for action in actions: + run_action(action, opts, global_config) + +def run_action(action, opts, global_config): + """ + Run a single action. opts are the parsed commandline options, + global_config is the parsed global configuration. + """ + # Split the action filename + parts = action.split('.', 2) + if (len(parts) < 2): + log.error('Invalid action filename: "%s". Should be in the form name.type, where type is a valid handler.') + return + (action_name, action_ty) = parts + + # Get the config for this action + action_config = config.get_action_config(opts, action) + # Create a handler for this action + handler = handlers.create_handler(action_ty, action_config) + + if handler: + # Run the handler + handler.run() + handler.finish() + # Silently skip invalid handlers, create_handler will have + # logged an error diff --git a/src/lib/backupninja/handlers/__init__.py b/src/lib/backupninja/handlers/__init__.py index e69de29..da07b6d 100644 --- a/src/lib/backupninja/handlers/__init__.py +++ b/src/lib/backupninja/handlers/__init__.py @@ -0,0 +1,81 @@ +# +# Backupninja python reimplementation, based on original backupninja program +# by riseup.net. +# Copyright (C) 2010 Matthijs Kooijman +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License along +# with this program; if not, write to the Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +""" Handler superclass with common functionality """ + +import sys +import logging as log + +class Handler(object): + def __init__(self, conf): + self.conf = conf + + def run(self): + """ + Run this handler for a single target. Override this method + in a subclass + """ + pass + + def finish(self): + """ + Called when all targets have been processed. Can be overridden + in a subclass. + """ + pass + +def create_handler(ty, conf): + """ + Create a new (subclass of) Handler object for an action with the + given type. conf is the configuration to pass to the handler. + + If the handler cannot be loaded, it is logged and None is returned + (but any exceptions raised by the handler code itself are not + handled). + """ + modname = 'backupninja.handlers.%s' % ty + # Load the handler if it is not loaded yet + if not modname in sys.modules: + try: + __import__(modname, globals(), locals(), []) + except ImportError, e: + log.error('Cannot load action handler for "%s": %s' + , ty, e) + return None + # Get the module from the module table + module = sys.modules[modname] + + # Check that the module has a "handler" top level function, which + # should create a new Handler object. + if not hasattr(module, 'handler'): + log.error('Action handler for "%s" (in "%s) is not valid: it ' + 'does not have a "handler" top level function.' + , ty, module.__file__) + return None + + # Call the "handler" function to create the actual handler + handler = module.handler(conf) + + # Check if the handler returned is really a subclass of Handler + if not isinstance(handler, Handler): + log.error('Action handler for "%s" (in "%s) is not valid: it ' + 'does not return a subclass of backupninja.handlers.Handler.' + , ty, module.__file__) + return None + return handler