[Kimchi-devel] [PATCH 04/16] Move basic controller resources to control/base.py

From: Aline Manera <alinefm(a)br.ibm.com&gt; Resource(), Collection() and AsyncCollection classes are base for all Kimchi resources. Move them to a separated file as they should not be changed with high frequency Signed-off-by: Aline Manera <alinefm(a)br.ibm.com&gt; --- Makefile.am | 1 + src/kimchi/control/base.py | 290 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 291 insertions(+) create mode 100644 src/kimchi/control/base.py diff --git a/Makefile.am b/Makefile.am index 65b39b8..997d4cc 100644 --- a/Makefile.am +++ b/Makefile.am @@ -45,6 +45,7 @@ PEP8_WHITELIST = \ src/kimchi/disks.py \ src/kimchi/root.py \ src/kimchi/server.py \ + src/kimchi/control/base.py \ src/kimchi/control/utils.py \ plugins/__init__.py \ plugins/sample/__init__.py \ diff --git a/src/kimchi/control/base.py b/src/kimchi/control/base.py new file mode 100644 index 0000000..22452fc --- /dev/null +++ b/src/kimchi/control/base.py @@ -0,0 +1,290 @@ +# +# Project Kimchi +# +# Copyright IBM, Corp. 2013 +# +# Authors: +# Adam Litke <agl(a)linux.vnet.ibm.com&gt; +# Aline Manera <alinefm(a)linix.vnet.ibm.com&gt; +# +# This library is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2.1 of the License, or (at your option) any later version. +# +# This library 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 +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + +import cherrypy +import urllib2 + + +import kimchi.template +from kimchi.control.utils import get_class_name, internal_redirect, model_fn +from kimchi.control.utils import parse_request, validate_method +from kimchi.control.utils import validate_params +from kimchi.exception import InvalidOperation, InvalidParameter +from kimchi.exception import MissingParameter, NotFoundError, OperationFailed + + +class Resource(object): + """ + A Resource represents a single entity in the API (such as a Virtual + Machine) + + To create new Resource types, subclass this and change the following things + in the child class: + + - If the Resource requires more than one identifier set self.model_args as + appropriate. This should only be necessary if this Resource is logically + nested. For example: A Storage Volume belongs to a Storage Pool so the + Storage Volume would set model args to (pool_ident, volume_ident). + + - Implement the base operations of 'lookup' and 'delete' in the model(s). + + - Set the 'data' property to a JSON-serializable representation of the + Resource. + """ + def __init__(self, model, ident=None): + self.model = model + self.ident = ident + self.model_args = (ident,) + self.update_params = [] + + def generate_action_handler(self, instance, action_name, action_args=None): + def wrapper(*args, **kwargs): + validate_method(('POST')) + try: + model_args = list(instance.model_args) + if action_args is not None: + model_args.extend(parse_request()[key] + for key in action_args) + fn = getattr(instance.model, model_fn(instance, action_name)) + fn(*model_args) + uri_params = tuple(instance.model_args) + raise internal_redirect(instance.uri_fmt % uri_params) + except MissingParameter, param: + error = "Missing parameter: '%s'" % param + raise cherrypy.HTTPError(400, error) + except InvalidParameter, param: + error = "Invalid parameter: '%s'" % param + raise cherrypy.HTTPError(400, error) + except InvalidOperation, msg: + raise cherrypy.HTTPError(400, "Invalid operation: '%s'" % msg) + except OperationFailed, msg: + raise cherrypy.HTTPError(500, "Operation Failed: '%s'" % msg) + except NotFoundError, msg: + raise cherrypy.HTTPError(404, "Not found: '%s'" % msg) + + wrapper.__name__ = action_name + wrapper.exposed = True + return wrapper + + def lookup(self): + try: + lookup = getattr(self.model, model_fn(self, 'lookup')) + self.info = lookup(*self.model_args) + except AttributeError: + self.info = {} + + def delete(self): + try: + fn = getattr(self.model, model_fn(self, 'delete')) + fn(*self.model_args) + cherrypy.response.status = 204 + except AttributeError: + error = "Delete is not allowed for %s" % get_class_name(self) + raise cherrypy.HTTPError(405, error) + except OperationFailed, msg: + raise cherrypy.HTTPError(500, "Operation Failed: '%s'" % msg) + except InvalidOperation, msg: + raise cherrypy.HTTPError(400, "Invalid operation: '%s'" % msg) + + @cherrypy.expose + def index(self): + method = validate_method(('GET', 'DELETE', 'PUT')) + if method == 'GET': + try: + return self.get() + except NotFoundError, msg: + raise cherrypy.HTTPError(404, "Not found: '%s'" % msg) + except InvalidOperation, msg: + raise cherrypy.HTTPError(400, "Invalid operation: '%s'" % msg) + except OperationFailed, msg: + raise cherrypy.HTTPError(406, "Operation failed: '%s'" % msg) + elif method == 'DELETE': + try: + return self.delete() + except NotFoundError, msg: + raise cherrypy.HTTPError(404, "Not found: '%s'" % msg) + elif method == 'PUT': + try: + return self.update() + except InvalidParameter, msg: + raise cherrypy.HTTPError(400, "Invalid parameter: '%s'" % msg) + except InvalidOperation, msg: + raise cherrypy.HTTPError(400, "Invalid operation: '%s'" % msg) + except NotFoundError, msg: + raise cherrypy.HTTPError(404, "Not found: '%s'" % msg) + + def update(self): + try: + update = getattr(self.model, model_fn(self, 'update')) + except AttributeError: + error = "%s does not implement update method" + raise cherrypy.HTTPError(405, error % get_class_name(self)) + + params = parse_request() + validate_params(params, self, 'update') + + if self.update_params is not None: + invalids = [v for v in params.keys() if + v not in self.update_params] + if invalids: + error = "%s are not allowed to be updated" % invalids + raise cherrypy.HTTPError(405, error) + + ident = update(self.ident, params) + if ident != self.ident: + uri_params = list(self.model_args[:-1]) + uri_params += [urllib2.quote(ident.encode('utf8'))] + raise cherrypy.HTTPRedirect(self.uri_fmt % tuple(uri_params), 303) + + return self.get() + + def get(self): + self.lookup() + return kimchi.template.render(get_class_name(self), self.data) + + @property + def data(self): + """ + Override this in inherited classes to provide the Resource + representation as a python dictionary. + """ + return {} + + +class Collection(object): + """ + A Collection is a container for Resource objects. To create a new + Collection type, subclass this and make the following changes to the child + class: + + - Set self.resource to the type of Resource that this Collection contains + + - Set self.resource_args. This can remain an empty list if the Resources + can be initialized with only one identifier. Otherwise, include + additional values as needed (eg. to identify a parent resource). + + - Set self.model_args. Similar to above, this is needed only if the model + needs additional information to identify this Collection. + + - Implement the base operations of 'create' and 'get_list' in the model. + """ + def __init__(self, model): + self.model = model + self.resource = Resource + self.resource_args = [] + self.model_args = [] + + def create(self, *args): + try: + create = getattr(self.model, model_fn(self, 'create')) + except AttributeError: + error = 'Create is not allowed for %s' % get_class_name(self) + raise cherrypy.HTTPError(405, error) + + params = parse_request() + validate_params(params, self, 'create') + args = self.model_args + [params] + name = create(*args) + cherrypy.response.status = 201 + args = self.resource_args + [name] + res = self.resource(self.model, *args) + + return res.get() + + def _get_resources(self): + try: + get_list = getattr(self.model, model_fn(self, 'get_list')) + idents = get_list(*self.model_args) + res_list = [] + for ident in idents: + # internal text, get_list changes ident to unicode for sorted + args = self.resource_args + [ident] + res = self.resource(self.model, *args) + res.lookup() + res_list.append(res) + return res_list + except AttributeError: + return [] + + def _cp_dispatch(self, vpath): + if vpath: + ident = vpath.pop(0) + # incoming text, from URL, is not unicode, need decode + args = self.resource_args + [ident.decode("utf-8")] + return self.resource(self.model, *args) + + def get(self): + resources = self._get_resources() + data = [] + for res in resources: + data.append(res.data) + return kimchi.template.render(get_class_name(self), data) + + @cherrypy.expose + def index(self, *args): + method = validate_method(('GET', 'POST')) + if method == 'GET': + try: + return self.get() + except InvalidOperation, param: + error = "Invalid operation: '%s'" % param + raise cherrypy.HTTPError(400, error) + except NotFoundError, param: + raise cherrypy.HTTPError(404, "Not found: '%s'" % param) + + elif method == 'POST': + try: + return self.create(*args) + except MissingParameter, param: + error = "Missing parameter: '%s'" % param + raise cherrypy.HTTPError(400, error) + except InvalidParameter, param: + error = "Invalid parameter: '%s'" % param + raise cherrypy.HTTPError(400, error) + except OperationFailed, param: + raise cherrypy.HTTPError(500, "Operation Failed: '%s'" % param) + except InvalidOperation, param: + error = "Invalid operation: '%s'" % param + raise cherrypy.HTTPError(400, error) + except NotFoundError, param: + raise cherrypy.HTTPError(404, "Not found: '%s'" % param) + + +class AsyncCollection(Collection): + """ + A Collection to create it's resource by asynchronous task + """ + def __init__(self, model): + super(AsyncCollection, self).__init__(model) + + def create(self, *args): + try: + create = getattr(self.model, model_fn(self, 'create')) + except AttributeError: + raise cherrypy.HTTPError(405, + 'Create is not allowed for %s' % get_class_name(self)) + params = parse_request() + args = self.model_args + [params] + task = create(*args) + cherrypy.response.status = 202 + return kimchi.template.render("Task", task) -- 1.7.10.4