Separate glance cache client from main client

This is relocating the necessary functionality for the glance
cache management tool into a new client class.

Related to bp separate-client

Change-Id: Ib89db1245aca5032a8d93876e07c562cb1fb5d4d

bin/glance-cache-manage

@@ -37,7 +37,7 @@ if os.path.exists(os.path.join(possible_topdir, 'glance', '__init__.py')):
 
 gettext.install('glance', unicode=1)
 
-from glance import client as glance_client
+import glance.image_cache.client
 from glance.common import exception
 from glance.common import utils
 from glance.version import version_info as version
@@ -258,7 +258,8 @@ def get_client(options):
     specified by the --host and --port options
     supplied to the CLI
     """
-    return glance_client.get_client(host=options.host,
+    return glance.image_cache.client.get_client(
+                host=options.host,
                 port=options.port,
                 username=options.os_username,
                 password=options.os_password,

glance/image_cache/client.py

@@ -0,0 +1,126 @@
+# Copyright 2012 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.
+
+import os
+
+from glance.common import client as base_client
+import glance.openstack.common.jsonutils as json
+from glance.common import exception
+
+
+class CacheClient(base_client.BaseClient):
+
+    DEFAULT_PORT = 9292
+    DEFAULT_DOC_ROOT = '/v1'
+
+    def delete_cached_image(self, image_id):
+        """
+        Delete a specified image from the cache
+        """
+        self.do_request("DELETE", "/cached_images/%s" % image_id)
+        return True
+
+    def get_cached_images(self, **kwargs):
+        """
+        Returns a list of images stored in the image cache.
+        """
+        res = self.do_request("GET", "/cached_images")
+        data = json.loads(res.read())['cached_images']
+        return data
+
+    def get_queued_images(self, **kwargs):
+        """
+        Returns a list of images queued for caching
+        """
+        res = self.do_request("GET", "/queued_images")
+        data = json.loads(res.read())['queued_images']
+        return data
+
+    def delete_all_cached_images(self):
+        """
+        Delete all cached images
+        """
+        res = self.do_request("DELETE", "/cached_images")
+        data = json.loads(res.read())
+        num_deleted = data['num_deleted']
+        return num_deleted
+
+    def queue_image_for_caching(self, image_id):
+        """
+        Queue an image for prefetching into cache
+        """
+        self.do_request("PUT", "/queued_images/%s" % image_id)
+        return True
+
+    def delete_queued_image(self, image_id):
+        """
+        Delete a specified image from the cache queue
+        """
+        self.do_request("DELETE", "/queued_images/%s" % image_id)
+        return True
+
+    def delete_all_queued_images(self):
+        """
+        Delete all queued images
+        """
+        res = self.do_request("DELETE", "/queued_images")
+        data = json.loads(res.read())
+        num_deleted = data['num_deleted']
+        return num_deleted
+
+
+def get_client(host, port=None, timeout=None, use_ssl=False, username=None,
+               password=None, tenant=None,
+               auth_url=None, auth_strategy=None,
+               auth_token=None, region=None,
+               is_silent_upload=False, insecure=False):
+    """
+    Returns a new client Glance client object based on common kwargs.
+    If an option isn't specified falls back to common environment variable
+    defaults.
+    """
+
+    if auth_url or os.getenv('OS_AUTH_URL'):
+        force_strategy = 'keystone'
+    else:
+        force_strategy = None
+
+    creds = dict(username=username or
+                         os.getenv('OS_AUTH_USER', os.getenv('OS_USERNAME')),
+                 password=password or
+                         os.getenv('OS_AUTH_KEY', os.getenv('OS_PASSWORD')),
+                 tenant=tenant or
+                         os.getenv('OS_AUTH_TENANT',
+                                 os.getenv('OS_TENANT_NAME')),
+                 auth_url=auth_url or os.getenv('OS_AUTH_URL'),
+                 strategy=force_strategy or auth_strategy or
+                          os.getenv('OS_AUTH_STRATEGY', 'noauth'),
+                 region=region or os.getenv('OS_REGION_NAME'),
+    )
+
+    if creds['strategy'] == 'keystone' and not creds['auth_url']:
+        msg = ("--os_auth_url option or OS_AUTH_URL environment variable "
+               "required when keystone authentication strategy is enabled\n")
+        raise exception.ClientConfigurationError(msg)
+
+    return CacheClient(
+            host=host,
+            port=port,
+            timeout=timeout,
+            use_ssl=use_ssl,
+            auth_tok=auth_token or
+            os.getenv('OS_TOKEN'),
+            creds=creds,
+            insecure=insecure)