Initial split from python-novaclient.0.0

1 files changed, 293 insertions, 0 deletions

diff --git a/cinderclient/base.py b/cinderclient/base.py
new file mode 100644
index 0000000..02d3549
--- /dev/null
+++ b/cinderclient/base.py
@@ -0,0 +1,293 @@
+# Copyright 2010 Jacob Kaplan-Moss
+
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""
+Base utilities to build API operation managers and objects on top of.
+"""
+
+import contextlib
+import hashlib
+import os
+from cinderclient import exceptions
+from cinderclient import utils
+
+
+# Python 2.4 compat
+try:
+    all
+except NameError:
+    def all(iterable):
+        return True not in (not x for x in iterable)
+
+
+def getid(obj):
+    """
+    Abstracts the common pattern of allowing both an object or an object's ID
+    as a parameter when dealing with relationships.
+    """
+    try:
+        return obj.id
+    except AttributeError:
+        return obj
+
+
+class Manager(utils.HookableMixin):
+    """
+    Managers interact with a particular type of API (servers, flavors, images,
+    etc.) and provide CRUD operations for them.
+    """
+    resource_class = None
+
+    def __init__(self, api):
+        self.api = api
+
+    def _list(self, url, response_key, obj_class=None, body=None):
+        resp = None
+        if body:
+            resp, body = self.api.client.post(url, body=body)
+        else:
+            resp, body = self.api.client.get(url)
+
+        if obj_class is None:
+            obj_class = self.resource_class
+
+        data = body[response_key]
+        # NOTE(ja): keystone returns values as list as {'values': [ ... ]}
+        #           unlike other services which just return the list...
+        if isinstance(data, dict):
+            try:
+                data = data['values']
+            except KeyError:
+                pass
+
+        with self.completion_cache('human_id', obj_class, mode="w"):
+            with self.completion_cache('uuid', obj_class, mode="w"):
+                return [obj_class(self, res, loaded=True)
+                        for res in data if res]
+
+    @contextlib.contextmanager
+    def completion_cache(self, cache_type, obj_class, mode):
+        """
+        The completion cache store items that can be used for bash
+        autocompletion, like UUIDs or human-friendly IDs.
+
+        A resource listing will clear and repopulate the cache.
+
+        A resource create will append to the cache.
+
+        Delete is not handled because listings are assumed to be performed
+        often enough to keep the cache reasonably up-to-date.
+        """
+        base_dir = utils.env('CINDERCLIENT_UUID_CACHE_DIR',
+                             default="~/.cinderclient")
+
+        # NOTE(sirp): Keep separate UUID caches for each username + endpoint
+        # pair
+        username = utils.env('OS_USERNAME', 'CINDER_USERNAME')
+        url = utils.env('OS_URL', 'CINDER_URL')
+        uniqifier = hashlib.md5(username + url).hexdigest()
+
+        cache_dir = os.path.expanduser(os.path.join(base_dir, uniqifier))
+
+        try:
+            os.makedirs(cache_dir, 0755)
+        except OSError:
+            # NOTE(kiall): This is typicaly either permission denied while
+            #              attempting to create the directory, or the directory
+            #              already exists. Either way, don't fail.
+            pass
+
+        resource = obj_class.__name__.lower()
+        filename = "%s-%s-cache" % (resource, cache_type.replace('_', '-'))
+        path = os.path.join(cache_dir, filename)
+
+        cache_attr = "_%s_cache" % cache_type
+
+        try:
+            setattr(self, cache_attr, open(path, mode))
+        except IOError:
+            # NOTE(kiall): This is typicaly a permission denied while
+            #              attempting to write the cache file.
+            pass
+
+        try:
+            yield
+        finally:
+            cache = getattr(self, cache_attr, None)
+            if cache:
+                cache.close()
+                delattr(self, cache_attr)
+
+    def write_to_completion_cache(self, cache_type, val):
+        cache = getattr(self, "_%s_cache" % cache_type, None)
+        if cache:
+            cache.write("%s\n" % val)
+
+    def _get(self, url, response_key=None):
+        resp, body = self.api.client.get(url)
+        if response_key:
+            return self.resource_class(self, body[response_key], loaded=True)
+        else:
+            return self.resource_class(self, body, loaded=True)
+
+    def _create(self, url, body, response_key, return_raw=False, **kwargs):
+        self.run_hooks('modify_body_for_create', body, **kwargs)
+        resp, body = self.api.client.post(url, body=body)
+        if return_raw:
+            return body[response_key]
+
+        with self.completion_cache('human_id', self.resource_class, mode="a"):
+            with self.completion_cache('uuid', self.resource_class, mode="a"):
+                return self.resource_class(self, body[response_key])
+
+    def _delete(self, url):
+        resp, body = self.api.client.delete(url)
+
+    def _update(self, url, body, **kwargs):
+        self.run_hooks('modify_body_for_update', body, **kwargs)
+        resp, body = self.api.client.put(url, body=body)
+        return body
+
+
+class ManagerWithFind(Manager):
+    """
+    Like a `Manager`, but with additional `find()`/`findall()` methods.
+    """
+    def find(self, **kwargs):
+        """
+        Find a single item with attributes matching ``**kwargs``.
+
+        This isn't very efficient: it loads the entire list then filters on
+        the Python side.
+        """
+        matches = self.findall(**kwargs)
+        num_matches = len(matches)
+        if num_matches == 0:
+            msg = "No %s matching %s." % (self.resource_class.__name__, kwargs)
+            raise exceptions.NotFound(404, msg)
+        elif num_matches > 1:
+            raise exceptions.NoUniqueMatch
+        else:
+            return matches[0]
+
+    def findall(self, **kwargs):
+        """
+        Find all items with attributes matching ``**kwargs``.
+
+        This isn't very efficient: it loads the entire list then filters on
+        the Python side.
+        """
+        found = []
+        searches = kwargs.items()
+
+        for obj in self.list():
+            try:
+                if all(getattr(obj, attr) == value
+                                    for (attr, value) in searches):
+                    found.append(obj)
+            except AttributeError:
+                continue
+
+        return found
+
+    def list(self):
+        raise NotImplementedError
+
+
+class Resource(object):
+    """
+    A resource represents a particular instance of an object (server, flavor,
+    etc). This is pretty much just a bag for attributes.
+
+    :param manager: Manager object
+    :param info: dictionary representing resource attributes
+    :param loaded: prevent lazy-loading if set to True
+    """
+    HUMAN_ID = False
+
+    def __init__(self, manager, info, loaded=False):
+        self.manager = manager
+        self._info = info
+        self._add_details(info)
+        self._loaded = loaded
+
+        # NOTE(sirp): ensure `id` is already present because if it isn't we'll
+        # enter an infinite loop of __getattr__ -> get -> __init__ ->
+        # __getattr__ -> ...
+        if 'id' in self.__dict__ and len(str(self.id)) == 36:
+            self.manager.write_to_completion_cache('uuid', self.id)
+
+        human_id = self.human_id
+        if human_id:
+            self.manager.write_to_completion_cache('human_id', human_id)
+
+    @property
+    def human_id(self):
+        """Subclasses may override this provide a pretty ID which can be used
+        for bash completion.
+        """
+        if 'name' in self.__dict__ and self.HUMAN_ID:
+            return utils.slugify(self.name)
+        return None
+
+    def _add_details(self, info):
+        for (k, v) in info.iteritems():
+            try:
+                setattr(self, k, v)
+            except AttributeError:
+                # In this case we already defined the attribute on the class
+                pass
+
+    def __getattr__(self, k):
+        if k not in self.__dict__:
+            #NOTE(bcwaldon): disallow lazy-loading if already loaded once
+            if not self.is_loaded():
+                self.get()
+                return self.__getattr__(k)
+
+            raise AttributeError(k)
+        else:
+            return self.__dict__[k]
+
+    def __repr__(self):
+        reprkeys = sorted(k for k in self.__dict__.keys() if k[0] != '_' and
+                                                                k != 'manager')
+        info = ", ".join("%s=%s" % (k, getattr(self, k)) for k in reprkeys)
+        return "<%s %s>" % (self.__class__.__name__, info)
+
+    def get(self):
+        # set_loaded() first ... so if we have to bail, we know we tried.
+        self.set_loaded(True)
+        if not hasattr(self.manager, 'get'):
+            return
+
+        new = self.manager.get(self.id)
+        if new:
+            self._add_details(new._info)
+
+    def __eq__(self, other):
+        if not isinstance(other, self.__class__):
+            return False
+        if hasattr(self, 'id') and hasattr(other, 'id'):
+            return self.id == other.id
+        return self._info == other._info
+
+    def is_loaded(self):
+        return self._loaded
+
+    def set_loaded(self, val):
+        self._loaded = val