Glance Image Service now understands how to use glance client to paginate through images.

3 files changed, 62 insertions, 29 deletions

diff --git a/nova/api/openstack/images.py b/nova/api/openstack/images.py
index c76738d30..b9bc83fde 100644
--- a/nova/api/openstack/images.py
+++ b/nova/api/openstack/images.py
@@ -143,7 +143,7 @@ class ControllerV10(Controller):
         """
         context = req.environ['nova.context']
         filters = self._get_filters(req)
-        images = self._image_service.index(context, filters)
+        images = self._image_service.index(context, filters=filters)
         images = common.limited(images, req)
         builder = self.get_builder(req).build
         return dict(images=[builder(image, detail=False) for image in images])
@@ -156,7 +156,7 @@ class ControllerV10(Controller):
         """
         context = req.environ['nova.context']
         filters = self._get_filters(req)
-        images = self._image_service.detail(context, filters)
+        images = self._image_service.detail(context, filters=filters)
         images = common.limited(images, req)
         builder = self.get_builder(req).build
         return dict(images=[builder(image, detail=True) for image in images])
diff --git a/nova/exception.py b/nova/exception.py
index 68e6ac937..792e306c1 100644
--- a/nova/exception.py
+++ b/nova/exception.py
@@ -150,6 +150,10 @@ class NovaException(Exception):
         return self._error_string
 
 
+class ImagePaginationFailed(NovaException):
+    message = _("Failed to paginate through images from image service")
+
+
 class VirtualInterfaceCreateException(NovaException):
     message = _("Virtual Interface creation failed")
 
diff --git a/nova/image/glance.py b/nova/image/glance.py
index 44a3c6f83..da93f0d1c 100644
--- a/nova/image/glance.py
+++ b/nova/image/glance.py
@@ -87,42 +87,71 @@ class GlanceImageService(service.BaseImageService):
         """Sets the client's auth token."""
         self.client.set_auth_token(context.auth_token)
 
-    def index(self, context, filters=None, marker=None, limit=None):
+    def index(self, context, **kwargs):
         """Calls out to Glance for a list of images available."""
-        # NOTE(sirp): We need to use `get_images_detailed` and not
-        # `get_images` here because we need `is_public` and `properties`
-        # included so we can filter by user
-        self._set_client_context(context)
-        filtered = []
-        filters = filters or {}
-        if 'is_public' not in filters:
-            # NOTE(vish): don't filter out private images
-            filters['is_public'] = 'none'
-        image_metas = self.client.get_images_detailed(filters=filters,
-                                                      marker=marker,
-                                                      limit=limit)
+        params = self._extract_query_params(kwargs)
+        image_metas = self._get_images(context, **params)
+
+        images = []
         for image_meta in image_metas:
+            # NOTE(sirp): We need to use `get_images_detailed` and not
+            # `get_images` here because we need `is_public` and `properties`
+            # included so we can filter by user
             if self._is_image_available(context, image_meta):
                 meta_subset = utils.subset_dict(image_meta, ('id', 'name'))
-                filtered.append(meta_subset)
-        return filtered
+                images.append(meta_subset)
+        return images
 
-    def detail(self, context, filters=None, marker=None, limit=None):
+    def detail(self, context, **kwargs):
         """Calls out to Glance for a list of detailed image information."""
-        self._set_client_context(context)
-        filtered = []
-        filters = filters or {}
-        if 'is_public' not in filters:
-            # NOTE(vish): don't filter out private images
-            filters['is_public'] = 'none'
-        image_metas = self.client.get_images_detailed(filters=filters,
-                                                      marker=marker,
-                                                      limit=limit)
+        params = self._extract_query_params(kwargs)
+        image_metas = self._get_images(context, **params)
+
+        images = []
         for image_meta in image_metas:
             if self._is_image_available(context, image_meta):
                 base_image_meta = self._translate_to_base(image_meta)
-                filtered.append(base_image_meta)
-        return filtered
+                images.append(base_image_meta)
+        return images
+
+    def _extract_query_params(self, params):
+        _params = {}
+        accepted_params = ('filters', 'marker', 'limit',
+                           'sort_key', 'sort_dir')
+        for param in accepted_params:
+            if param in params:
+                _params[param] = params.get(param)
+
+        return _params
+
+    def _get_images(self, context, **kwargs):
+        """Get image entitites from images service"""
+        self._set_client_context(context)
+
+        # ensure filters is a dict
+        kwargs['filters'] = kwargs.get('filters') or {}
+        # NOTE(vish): don't filter out private images
+        kwargs['filters'].setdefault('is_public', 'none')
+
+        return self._fetch_images(self.client.get_images_detailed, **kwargs)
+
+    def _fetch_images(self, fetch_func, **kwargs):
+        """Paginate through results from glance server"""
+        images = fetch_func(**kwargs)
+
+        for image in images:
+            yield image
+        else:
+            # break out of recursive loop to end pagination
+            return
+
+        try:
+            # attempt to advance the marker in order to fetch next page
+            kwargs['marker'] = images[-1]['id']
+        except KeyError:
+            raise exception.ImagePaginationFailed()
+
+        self._fetch_images(fetch_func, **kwargs)
 
     def show(self, context, image_id):
         """Returns a dict with image data for the given opaque image id."""