X-Git-Url: https://git.llucax.com/software/pymin.git/blobdiff_plain/1387b81089b4c053c0f07447fafe36e6b6394d7e..865ddb235489f38afd7043ee269e4f958474bd5a:/pymin/services/util.py diff --git a/pymin/services/util.py b/pymin/services/util.py index e5aa202..2fe7f9b 100644 --- a/pymin/services/util.py +++ b/pymin/services/util.py @@ -9,13 +9,16 @@ try: except ImportError: import pickle -from pymin.dispatcher import Handler, handler, HandlerError +from pymin.dispatcher import Handler, handler, HandlerError, \ + CommandNotFoundError -DEBUG = False -#DEBUG = True +#DEBUG = False +DEBUG = True -__ALL__ = ('ServiceHandler', 'InitdHandler', 'Persistent', 'ConfigWriter', - 'Error', 'ReturnNot0Error', 'ExecutionError', 'call') +__ALL__ = ('ServiceHandler', 'RestartHandler', 'ReloadHandler', 'InitdHandler', + 'SubHandler', 'DictSubHandler', 'ListSubHandler', 'Persistent', + 'ConfigWriter', 'Error', 'ReturnNot0Error', 'ExecutionError', + 'ItemError', 'ItemAlreadyExistsError', 'ItemNotFoundError', 'call') class Error(HandlerError): r""" @@ -79,7 +82,7 @@ class ParameterError(Error, KeyError): class ParameterNotFoundError(ParameterError): r""" - ParameterNotFoundError(hostname) -> ParameterNotFoundError instance + ParameterNotFoundError(paramname) -> ParameterNotFoundError instance This exception is raised when trying to operate on a parameter that doesn't exists. @@ -89,6 +92,40 @@ class ParameterNotFoundError(ParameterError): r"Initialize the object. See class documentation for more info." self.message = 'Parameter not found: "%s"' % paramname +class ItemError(Error, KeyError): + r""" + ItemError(key) -> ItemError instance. + + This is the base exception for all item related errors. + """ + + def __init__(self, key): + r"Initialize the object. See class documentation for more info." + self.message = u'Item error: "%s"' % key + +class ItemAlreadyExistsError(ItemError): + r""" + ItemAlreadyExistsError(key) -> ItemAlreadyExistsError instance. + + This exception is raised when trying to add an item that already exists. + """ + + def __init__(self, key): + r"Initialize the object. See class documentation for more info." + self.message = u'Item already exists: "%s"' % key + +class ItemNotFoundError(ItemError): + r""" + ItemNotFoundError(key) -> ItemNotFoundError instance. + + This exception is raised when trying to operate on an item that doesn't + exists. + """ + + def __init__(self, key): + r"Initialize the object. See class documentation for more info." + self.message = u'Item not found: "%s"' % key + def call(command, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=True, universal_newlines=True, @@ -246,18 +283,24 @@ class ConfigWriter: class TestHandler(ConfigWriter): _config_writer_files = ('base.conf', 'custom.conf') - _config_writer_cfg_dir = '/etc/service' + _config_writer_cfg_dir = { + 'base.conf': '/etc/service', + 'custom.conf': '/etc/service/conf.d', + } _config_writer_tpl_dir = 'templates' The generated configuration files directory defaults to '.' and the templates directory to 'templates'. _config_writer_files has no default and must be specified in either way. It can be string or a tuple if more than - one configuration file must be generated. + one configuration file must be generated. _config_writer_cfg_dir could be a + dict mapping which file should be stored in which directory, or a single + string if all the config files should go to the same directory. The template filename and the generated configuration filename are both the same (so if you want to generate some /etc/config, you should have some templates/config template). That's why _config_writer_cfg_dir and - _config_writer_tpl_dir can't be the same. + _config_writer_tpl_dir can't be the same. This is not true for very + specific cases where _write_single_config() is used. When you write your Handler, you should call _config_build_templates() in you Handler constructor to build the templates. @@ -313,6 +356,15 @@ class ConfigWriter: vars = vars(template_name) return self._config_writer_templates[template_name].render(**vars) + def _get_config_path(self, template_name, config_filename=None): + r"Get a complete configuration path." + if not config_filename: + config_filename = template_name + if isinstance(self._config_writer_cfg_dir, basestring): + return path.join(self._config_writer_cfg_dir, config_filename) + return path.join(self._config_writer_cfg_dir[template_name], + config_filename) + def _write_single_config(self, template_name, config_filename=None, vars=None): r"""_write_single_config(template_name[, config_filename[, vars]]). @@ -325,8 +377,6 @@ class ConfigWriter: variables to replace in the templates, if not, it looks for a _get_config_vars() method to get it. """ - if not config_filename: - config_filename = template_name if vars is None: if hasattr(self, '_get_config_vars'): vars = self._get_config_vars(template_name) @@ -334,7 +384,7 @@ class ConfigWriter: vars = dict() elif callable(vars): vars = vars(template_name) - f = file(path.join(self._config_writer_cfg_dir, config_filename), 'w') + f = file(self._get_config_path(template_name, config_filename), 'w') ctx = Context(f, **vars) self._config_writer_templates[template_name].render_context(ctx) f.close() @@ -397,6 +447,32 @@ class ServiceHandler(Handler): r"reload() -> None :: Reload the configuration of the service." call(self._service_reload) +class RestartHandler(Handler): + r"""RestartHandler() -> RestartHandler :: Provides generic restart command. + + This is a helper class to inherit from to automatically add a restart + command that first stop the service and then starts it again (using start + and stop commands respectively). + """ + + @handler(u'Restart the service (alias to stop + start).') + def restart(self): + r"restart() -> None :: Restart the service calling stop() and start()." + self.stop() + self.start() + +class ReloadHandler(Handler): + r"""ReloadHandler() -> ReloadHandler :: Provides generic reload command. + + This is a helper class to inherit from to automatically add a reload + command that calls restart. + """ + + @handler(u'Reload the service config (alias to restart).') + def reload(self): + r"reload() -> None :: Reload the configuration of the service." + self.restart() + class InitdHandler(Handler): r"""InitdHandler([initd_name[, initd_dir]]) -> InitdHandler. @@ -527,6 +603,207 @@ class ParametersHandler(Handler): r"show() -> (key, value) tuples :: List all the parameters." return self.params.items() +class SubHandler(Handler): + r"""SubHandler(parent) -> SubHandler instance :: Handles subcommands. + + This is a helper class to build sub handlers that needs to reference the + parent handler. + + parent - Parent Handler object. + """ + + def __init__(self, parent): + r"Initialize the object, see the class documentation for details." + self.parent = parent + +class ContainerSubHandler(SubHandler): + r"""ContainerSubHandler(parent) -> ContainerSubHandler instance. + + This is a helper class to implement ListSubHandler and DictSubHandler. You + should not use it directly. + + The container attribute to handle and the class of objects that it + contains can be defined by calling the constructor or in a more declarative + way as class attributes, like: + + class TestHandler(ContainerSubHandler): + _cont_subhandler_attr = 'some_cont' + _cont_subhandler_class = SomeClass + + This way, the parent's some_cont attribute (self.parent.some_cont) + will be managed automatically, providing the commands: add, update, + delete, get and show. New items will be instances of SomeClass, + which should provide a cmp operator to see if the item is on the + container and an update() method, if it should be possible to modify + it. If SomeClass has an _add, _update or _delete attribute, it set + them to true when the item is added, updated or deleted respectively + (in case that it's deleted, it's not removed from the container, + but it's not listed either). + """ + + def __init__(self, parent, attr=None, cls=None): + r"Initialize the object, see the class documentation for details." + self.parent = parent + if attr is not None: + self._cont_subhandler_attr = attr + if cls is not None: + self._cont_subhandler_class = cls + + def _attr(self, attr=None): + if attr is None: + return getattr(self.parent, self._cont_subhandler_attr) + setattr(self.parent, self._cont_subhandler_attr, attr) + + def _vattr(self): + if isinstance(self._attr(), dict): + return dict([(k, i) for (k, i) in self._attr().items() + if not hasattr(i, '_delete') or not i._delete]) + return [i for i in self._attr() + if not hasattr(i, '_delete') or not i._delete] + + @handler(u'Add a new item') + def add(self, *args, **kwargs): + r"add(...) -> None :: Add an item to the list." + item = self._cont_subhandler_class(*args, **kwargs) + if hasattr(item, '_add'): + item._add = True + key = item + if isinstance(self._attr(), dict): + key = item.as_tuple()[0] + # do we have the same item? then raise an error + if key in self._vattr(): + raise ItemAlreadyExistsError(item) + # do we have the same item, but logically deleted? then update flags + if key in self._attr(): + index = key + if not isinstance(self._attr(), dict): + index = self._attr().index(item) + if hasattr(item, '_add'): + self._attr()[index]._add = False + if hasattr(item, '_delete'): + self._attr()[index]._delete = False + else: # it's *really* new + if isinstance(self._attr(), dict): + self._attr()[key] = item + else: + self._attr().append(item) + + @handler(u'Update an item') + def update(self, index, *args, **kwargs): + r"update(index, ...) -> None :: Update an item of the container." + # TODO make it right with metaclasses, so the method is not created + # unless the update() method really exists. + # TODO check if the modified item is the same of an existing one + if not isinstance(self._attr(), dict): + index = int(index) # TODO validation + if not hasattr(self._cont_subhandler_class, 'update'): + raise CommandNotFoundError(('update',)) + try: + item = self._vattr()[index] + item.update(*args, **kwargs) + if hasattr(item, '_update'): + item._update = True + except IndexError: + raise ItemNotFoundError(index) + + @handler(u'Delete an item') + def delete(self, index): + r"delete(index) -> None :: Delete an item of the container." + if not isinstance(self._attr(), dict): + index = int(index) # TODO validation + try: + item = self._vattr()[index] + if hasattr(item, '_delete'): + item._delete = True + else: + del self._attr()[index] + return item + except IndexError: + raise ItemNotFoundError(index) + + @handler(u'Remove all items (use with care).') + def clear(self): + if isinstance(self._attr(), dict): + self._attr.clear() + else: + self._attr(list()) + + @handler(u'Get information about an item') + def get(self, index): + r"get(index) -> item :: List all the information of an item." + if not isinstance(self._attr(), dict): + index = int(index) # TODO validation + try: + return self._vattr()[index] + except IndexError: + raise ItemNotFoundError(index) + + @handler(u'Get information about all items') + def show(self): + r"show() -> list of items :: List all the complete items information." + if isinstance(self._attr(), dict): + return self._attr().values() + return self._vattr() + +class ListSubHandler(ContainerSubHandler): + r"""ListSubHandler(parent) -> ListSubHandler instance. + + This is a helper class to inherit from to automatically handle subcommands + that operates over a list parent attribute. + + The list attribute to handle and the class of objects that it contains can + be defined by calling the constructor or in a more declarative way as + class attributes, like: + + class TestHandler(ListSubHandler): + _cont_subhandler_attr = 'some_list' + _cont_subhandler_class = SomeClass + + This way, the parent's some_list attribute (self.parent.some_list) will be + managed automatically, providing the commands: add, update, delete, get, + list and show. New items will be instances of SomeClass, which should + provide a cmp operator to see if the item is on the list and an update() + method, if it should be possible to modify it. If SomeClass has an _add, + _update or _delete attribute, it set them to true when the item is added, + updated or deleted respectively (in case that it's deleted, it's not + removed from the list, but it's not listed either). + """ + + @handler(u'Get how many items are in the list') + def len(self): + r"len() -> int :: Get how many items are in the list." + return len(self._vattr()) + +class DictSubHandler(ContainerSubHandler): + r"""DictSubHandler(parent) -> DictSubHandler instance. + + This is a helper class to inherit from to automatically handle subcommands + that operates over a dict parent attribute. + + The dict attribute to handle and the class of objects that it contains can + be defined by calling the constructor or in a more declarative way as + class attributes, like: + + class TestHandler(DictSubHandler): + _cont_subhandler_attr = 'some_dict' + _cont_subhandler_class = SomeClass + + This way, the parent's some_dict attribute (self.parent.some_dict) will be + managed automatically, providing the commands: add, update, delete, get, + list and show. New items will be instances of SomeClass, which should + provide a constructor with at least the key value, an as_tuple() method + and an update() method, if it should be possible to modify + it. If SomeClass has an _add, _update or _delete attribute, it set + them to true when the item is added, updated or deleted respectively + (in case that it's deleted, it's not removed from the dict, but it's + not listed either). + """ + + @handler(u'List all the items by key') + def list(self): + r"list() -> tuple :: List all the item keys." + return self._attr().keys() + if __name__ == '__main__':