Merge "Add a method to download an image from glance"

shade/openstackcloud.py

@@ -1564,6 +1564,46 @@ class OpenStackCloud(object):
         """
         return _utils._get_entity(self.search_images, name_or_id, filters)
 
+    def download_image(self, name_or_id, output_path=None, output_file=None):
+        """Download an image from glance by name or ID
+
+        :param str name_or_id: Name or ID of the image.
+        :param output_path: the output path to write the image to. Either this
+            or output_file must be specified
+        :param output_file: a file object (or file-like object) to write the
+            image data to. Only write() will be called on this object. Either
+            this or output_path must be specified
+
+        :raises: OpenStackCloudException in the event download_image is called
+            without exactly one of either output_path or output_file
+        :raises: OpenStackCloudResourceNotFound if no images are found matching
+            the name or id provided
+        """
+        if output_path is None and output_file is None:
+            raise OpenStackCloudException('No output specified, an output path'
+                                          ' or file object is necessary to '
+                                          'write the image data to')
+        elif output_path is not None and output_file is not None:
+            raise OpenStackCloudException('Both an output path and file object'
+                                          ' were provided, however only one '
+                                          'can be used at once')
+
+        image = self.search_images(name_or_id)
+        if len(image) == 0:
+            raise OpenStackCloudResourceNotFound(
+                "No images with name or id %s were found" % name_or_id)
+        image_contents = self.glance_client.images.data(image[0]['id'])
+        with _utils.shade_exceptions("Unable to download image"):
+            if output_path:
+                with open(output_path, 'wb') as fd:
+                    for chunk in image_contents:
+                        fd.write(chunk)
+                return
+            elif output_file:
+                for chunk in image_contents:
+                    output_file.write(chunk)
+                return
+
     def get_floating_ip(self, id, filters=None):
         """Get a floating IP by ID
 

shade/tests/functional/test_image.py

@@ -19,6 +19,8 @@ test_compute
 Functional tests for `shade` image methods.
 """
 
+import filecmp
+import os
 import tempfile
 
 from shade import openstack_cloud
@@ -47,3 +49,23 @@ class TestImage(base.TestCase):
                                     wait=True)
         finally:
             self.cloud.delete_image(image_name, wait=True)
+
+    def test_download_image(self):
+        test_image = tempfile.NamedTemporaryFile(delete=False)
+        self.addCleanup(os.remove, test_image.name)
+        test_image.write('\0' * 1024 * 1024)
+        test_image.close()
+        image_name = self.getUniqueString('image')
+        self.cloud.create_image(name=image_name,
+                                filename=test_image.name,
+                                disk_format='raw',
+                                container_format='bare',
+                                min_disk=10,
+                                min_ram=1024,
+                                wait=True)
+        self.addCleanup(self.cloud.delete_image, image_name, wait=True)
+        output = os.path.join(tempfile.gettempdir(), self.getUniqueString())
+        self.cloud.download_image(image_name, output)
+        self.addCleanup(os.remove, output)
+        self.assertTrue(filecmp.cmp(test_image.name, output),
+                        "Downloaded contents don't match created image")

shade/tests/unit/test_image.py

@@ -0,0 +1,99 @@
+# Copyright 2016 Hewlett-Packard Development Company, L.P.
+#
+# 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 tempfile
+import uuid
+
+import mock
+import six
+
+import shade
+from shade import exc
+from shade.tests import base
+
+
+class TestImage(base.TestCase):
+
+    def setUp(self):
+        super(TestImage, self).setUp()
+        self.cloud = shade.openstack_cloud(validate=False)
+        self.image_id = str(uuid.uuid4())
+        self.fake_search_return = [{
+            u'image_state': u'available',
+            u'container_format': u'bare',
+            u'min_ram': 0,
+            u'ramdisk_id': None,
+            u'updated_at': u'2016-02-10T05:05:02Z',
+            u'file': '/v2/images/' + self.image_id + '/file',
+            u'size': 3402170368,
+            u'image_type': u'snapshot',
+            u'disk_format': u'qcow2',
+            u'id': self.image_id,
+            u'schema': u'/v2/schemas/image',
+            u'status': u'active',
+            u'tags': [],
+            u'visibility': u'private',
+            u'locations': [{
+                u'url': u'http://127.0.0.1/images/' + self.image_id,
+                u'metadata': {}}],
+            u'min_disk': 40,
+            u'virtual_size': None,
+            u'name': u'fake_image',
+            u'checksum': u'ee36e35a297980dee1b514de9803ec6d',
+            u'created_at': u'2016-02-10T05:03:11Z',
+            u'protected': False}]
+        self.output = six.BytesIO()
+        self.output.write(uuid.uuid4().bytes)
+        self.output.seek(0)
+
+    def test_download_image_no_output(self):
+        self.assertRaises(exc.OpenStackCloudException,
+                          self.cloud.download_image, 'fake_image')
+
+    def test_download_image_two_outputs(self):
+        fake_fd = six.BytesIO()
+        self.assertRaises(exc.OpenStackCloudException,
+                          self.cloud.download_image, 'fake_image',
+                          output_path='fake_path', output_file=fake_fd)
+
+    @mock.patch.object(shade.OpenStackCloud, 'search_images', return_value=[])
+    def test_download_image_no_images_found(self, mock_search):
+        self.assertRaises(exc.OpenStackCloudResourceNotFound,
+                          self.cloud.download_image, 'fake_image',
+                          output_path='fake_path')
+
+    @mock.patch.object(shade.OpenStackCloud, 'glance_client')
+    @mock.patch.object(shade.OpenStackCloud, 'search_images')
+    def test_download_image_with_fd(self, mock_search, mock_glance):
+        output_file = six.BytesIO()
+        mock_glance.images.data.return_value = self.output
+        mock_search.return_value = self.fake_search_return
+        self.cloud.download_image('fake_image', output_file=output_file)
+        mock_glance.images.data.assert_called_once_with(self.image_id)
+        output_file.seek(0)
+        self.output.seek(0)
+        self.assertEqual(output_file.read(), self.output.read())
+
+    @mock.patch.object(shade.OpenStackCloud, 'glance_client')
+    @mock.patch.object(shade.OpenStackCloud, 'search_images')
+    def test_download_image_with_path(self, mock_search, mock_glance):
+        output_file = tempfile.NamedTemporaryFile()
+        mock_glance.images.data.return_value = self.output
+        mock_search.return_value = self.fake_search_return
+        self.cloud.download_image('fake_image',
+                                  output_path=output_file.name)
+        mock_glance.images.data.assert_called_once_with(self.image_id)
+        output_file.seek(0)
+        self.output.seek(0)
+        self.assertEqual(output_file.read(), self.output.read())