Add lifecycle support to buckets.

See: https://cloud.google.com/storage/docs/lifecycle and
     https://cloud.google.com/storage/docs/json_api/v1/buckets

Addresses 'lifecycle' 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',
+        'lifecycle': 'get_lifecycle',
     }
     """Mapping of field name -> accessor for fields w/ custom accessors."""
 
@@ -441,6 +442,35 @@ def make_public(self, recursive=False, future=False):
                 key.get_acl().all().grant_read()
                 key.save_acl()
 
+    def get_lifecycle(self):
+        """Retrieve CORS policies configured for this bucket.
+
+        See: https://cloud.google.com/storage/docs/lifecycle and
+             https://cloud.google.com/storage/docs/json_api/v1/buckets
+
+        :rtype: list(dict)
+        :returns: A sequence of mappings describing each CORS policy.
+        """
+        if not self.has_metadata('lifecycle'):
+            self.reload_metadata()
+        result = []
+        info = self.metadata.get('lifecycle', {})
+        for rule in info.get('rule', ()):
+            rule = rule.copy()
+            result.append(rule)
+        return result
+
+    def update_lifecycle(self, rules):
+        """Update CORS policies configured for this bucket.
+
+        See: https://cloud.google.com/storage/docs/lifecycle and
+             https://cloud.google.com/storage/docs/json_api/v1/buckets
+
+        :type rules: list(dict)
+        :param rules: A sequence of mappings describing each lifecycle policy.
+        """
+        self.patch_metadata({'lifecycle': {'rule': rules}})
+
 
 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_lifecycle_no_default(self):
+        NAME = 'name'
+        connection = _Connection()
+        bucket = self._makeOne(connection, NAME)
+        self.assertRaises(KeyError, bucket.get_metadata, 'lifecycle')
+        kw = connection._requested
+        self.assertEqual(len(kw), 0)
+
+    def test_get_metadata_lifecycle_w_default(self):
+        NAME = 'name'
+        connection = _Connection()
+        bucket = self._makeOne(connection, NAME)
+        default = object()
+        self.assertRaises(KeyError, bucket.get_metadata, 'lifecycle', default)
+        kw = connection._requested
+        self.assertEqual(len(kw), 0)
+
     def test_get_metadata_miss(self):
         NAME = 'name'
         before = {'bar': 'Bar'}
@@ -713,6 +730,53 @@ 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_lifecycle_eager(self):
+        NAME = 'name'
+        LC_RULE = {'action': {'type': 'Delete'}, 'condition': {'age': 42}}
+        before = {'lifecycle': {'rule': [LC_RULE]}}
+        connection = _Connection()
+        bucket = self._makeOne(connection, NAME, before)
+        entries = bucket.get_lifecycle()
+        self.assertEqual(len(entries), 1)
+        self.assertEqual(entries[0]['action']['type'], 'Delete')
+        self.assertEqual(entries[0]['condition']['age'], 42)
+        kw = connection._requested
+        self.assertEqual(len(kw), 0)
+
+    def test_get_lifecycle_lazy(self):
+        NAME = 'name'
+        LC_RULE = {'action': {'type': 'Delete'}, 'condition': {'age': 42}}
+        after = {'lifecycle': {'rule': [LC_RULE]}}
+        connection = _Connection(after)
+        bucket = self._makeOne(connection, NAME)
+        entries = bucket.get_lifecycle()
+        self.assertEqual(len(entries), 1)
+        self.assertEqual(entries[0]['action']['type'], 'Delete')
+        self.assertEqual(entries[0]['condition']['age'], 42)
+        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_lifecycle(self):
+        NAME = 'name'
+        LC_RULE = {'action': {'type': 'Delete'}, 'condition': {'age': 42}}
+        after = {'lifecycle': {'rule': [LC_RULE]}}
+        connection = _Connection(after)
+        bucket = self._makeOne(connection, NAME)
+        bucket.update_lifecycle([LC_RULE])
+        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_lifecycle()
+        self.assertEqual(len(entries), 1)
+        self.assertEqual(entries[0]['action']['type'], 'Delete')
+        self.assertEqual(entries[0]['condition']['age'], 42)
+
 
 class TestBucketIterator(unittest2.TestCase):