Add CORS support to buckets.

See: http://www.w3.org/TR/cors/ and
     https://cloud.google.com/storage/docs/json_api/v1/buckets

Addresses 'cors' part of 314.

Author: tseaver

gcloud/storage/bucket.py

@@ -24,6 +24,7 @@ class Bucket(_MetadataMixin):
     CUSTOM_METADATA_FIELDS = {
         'acl': 'get_acl',
         'defaultObjectAcl': 'get_default_object_acl',
+        'cors': 'get_cors',
     }
     """Mapping of field name -> accessor for fields w/ custom accessors."""
 
@@ -441,6 +442,58 @@ def make_public(self, recursive=False, future=False):
                 key.get_acl().all().grant_read()
                 key.save_acl()
 
+    def get_cors(self):
+        """Retrieve CORS policies configured for this bucket.
+
+        See: http://www.w3.org/TR/cors/ and
+             https://cloud.google.com/storage/docs/json_api/v1/buckets
+
+        :rtype: list(dict)
+        :returns: A sequence of mappings describing each CORS policy.
+                  Keys include 'max_age', 'methods', 'origins', and
+                  'headers'.
+        """
+        if not self.has_metadata('cors'):
+            self.reload_metadata()
+        result = []
+        for entry in self.metadata.get('cors', ()):
+            entry = entry.copy()
+            result.append(entry)
+            if 'maxAgeSeconds' in entry:
+                entry['max_age'] = entry.pop('maxAgeSeconds')
+            if 'method' in entry:
+                entry['methods'] = entry.pop('method')
+            if 'origin' in entry:
+                entry['origins'] = entry.pop('origin')
+            if 'responseHeader' in entry:
+                entry['headers'] = entry.pop('responseHeader')
+        return result
+
+    def update_cors(self, entries):
+        """Update CORS policies configured for this bucket.
+
+        See: http://www.w3.org/TR/cors/ and
+             https://cloud.google.com/storage/docs/json_api/v1/buckets
+
+        :type entries: list(dict)
+        :param entries: A sequence of mappings describing each CORS policy.
+                        Keys include 'max_age', 'methods', 'origins', and
+                        'headers'.
+        """
+        to_patch = []
+        for entry in entries:
+            entry = entry.copy()
+            to_patch.append(entry)
+            if 'max_age' in entry:
+                entry['maxAgeSeconds'] = entry.pop('max_age')
+            if 'methods' in entry:
+                entry['method'] = entry.pop('methods')
+            if 'origins' in entry:
+                entry['origin'] = entry.pop('origins')
+            if 'headers' in entry:
+                entry['responseHeader'] = entry.pop('headers')
+        self.patch_metadata({'cors': to_patch})
+
 
 class BucketIterator(Iterator):
     """An iterator listing all buckets.

gcloud/storage/test_bucket.py

@@ -489,6 +489,23 @@ def test_get_metadata_none_set_defaultObjectAcl_miss_clear_default(self):
         kw = connection._requested
         self.assertEqual(len(kw), 0)
 
+    def test_get_metadata_cors_no_default(self):
+        NAME = 'name'
+        connection = _Connection()
+        bucket = self._makeOne(connection, NAME)
+        self.assertRaises(KeyError, bucket.get_metadata, 'cors')
+        kw = connection._requested
+        self.assertEqual(len(kw), 0)
+
+    def test_get_metadata_none_set_cors_w_default(self):
+        NAME = 'name'
+        connection = _Connection()
+        bucket = self._makeOne(connection, NAME)
+        default = object()
+        self.assertRaises(KeyError, bucket.get_metadata, 'cors', default)
+        kw = connection._requested
+        self.assertEqual(len(kw), 0)
+
     def test_get_metadata_miss(self):
         NAME = 'name'
         before = {'bar': 'Bar'}
@@ -713,6 +730,77 @@ def get_items_from_response(self, response):
         self.assertEqual(kw[1]['path'], '/b/%s/o' % NAME)
         self.assertEqual(kw[1]['query_params'], None)
 
+    def test_get_cors_eager(self):
+        NAME = 'name'
+        CORS_ENTRY = {
+            'maxAgeSeconds': 1234,
+            'method': ['OPTIONS', 'GET'],
+            'origin': ['127.0.0.1'],
+            'responseHeader': ['Content-Type'],
+            }
+        before = {'cors': [CORS_ENTRY, {}]}
+        connection = _Connection()
+        bucket = self._makeOne(connection, NAME, before)
+        entries = bucket.get_cors()
+        self.assertEqual(len(entries), 2)
+        self.assertEqual(entries[0]['max_age'], CORS_ENTRY['maxAgeSeconds'])
+        self.assertEqual(entries[0]['methods'], CORS_ENTRY['method'])
+        self.assertEqual(entries[0]['origins'], CORS_ENTRY['origin'])
+        self.assertEqual(entries[0]['headers'], CORS_ENTRY['responseHeader'])
+        self.assertEqual(entries[1], {})
+        kw = connection._requested
+        self.assertEqual(len(kw), 0)
+
+    def test_get_cors_lazy(self):
+        NAME = 'name'
+        CORS_ENTRY = {
+            'maxAgeSeconds': 1234,
+            'method': ['OPTIONS', 'GET'],
+            'origin': ['127.0.0.1'],
+            'responseHeader': ['Content-Type'],
+            }
+        after = {'cors': [CORS_ENTRY]}
+        connection = _Connection(after)
+        bucket = self._makeOne(connection, NAME)
+        entries = bucket.get_cors()
+        self.assertEqual(len(entries), 1)
+        self.assertEqual(entries[0]['max_age'], CORS_ENTRY['maxAgeSeconds'])
+        self.assertEqual(entries[0]['methods'], CORS_ENTRY['method'])
+        self.assertEqual(entries[0]['origins'], CORS_ENTRY['origin'])
+        self.assertEqual(entries[0]['headers'], CORS_ENTRY['responseHeader'])
+        kw = connection._requested
+        self.assertEqual(len(kw), 1)
+        self.assertEqual(kw[0]['method'], 'GET')
+        self.assertEqual(kw[0]['path'], '/b/%s' % NAME)
+        self.assertEqual(kw[0]['query_params'], {'projection': 'noAcl'})
+
+    def test_update_cors(self):
+        NAME = 'name'
+        CORS_ENTRY = {
+            'maxAgeSeconds': 1234,
+            'method': ['OPTIONS', 'GET'],
+            'origin': ['127.0.0.1'],
+            'responseHeader': ['Content-Type'],
+            }
+        MAPPED = {
+            'max_age': 1234,
+            'methods': ['OPTIONS', 'GET'],
+            'origins': ['127.0.0.1'],
+            'headers': ['Content-Type'],
+            }
+        after = {'cors': [CORS_ENTRY, {}]}
+        connection = _Connection(after)
+        bucket = self._makeOne(connection, NAME)
+        bucket.update_cors([MAPPED, {}])
+        kw = connection._requested
+        self.assertEqual(len(kw), 1)
+        self.assertEqual(kw[0]['method'], 'PATCH')
+        self.assertEqual(kw[0]['path'], '/b/%s' % NAME)
+        self.assertEqual(kw[0]['data'], after)
+        self.assertEqual(kw[0]['query_params'], {'projection': 'full'})
+        entries = bucket.get_cors()
+        self.assertEqual(entries, [MAPPED, {}])
+
 
 class TestBucketIterator(unittest2.TestCase):