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

Aline Manera alinefm at linux.vnet.ibm.com
Mon Dec 23 18:41:19 UTC 2013


From: Aline Manera <alinefm at br.ibm.com>

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 at br.ibm.com>
---
 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 at linux.vnet.ibm.com>
+#  Aline Manera <alinefm at linix.vnet.ibm.com>
+#
+# 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




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