Fix the deletion of non-existent keys

On vanilla Swift, deleting an object that doesn't exist will 404.
On AWS, deleting a key that doesn't exist will either 404 if the bucket
doesn't exist (with a NoSuchBucket code) or 204 (because yep, that's not
accessible).

Change-Id: Ied2a78b56522316bb374f23961621641af3adc83
Related-Change: I6e154594dfda6c3065774c23b24f728625a842bc

swift/common/middleware/s3api/controllers/obj.py

@@ -20,7 +20,7 @@ from swift.common.utils import public
 from swift.common.middleware.s3api.utils import S3Timestamp
 from swift.common.middleware.s3api.controllers.base import Controller
 from swift.common.middleware.s3api.s3response import S3NotImplemented, \
-    InvalidRange, NoSuchKey, InvalidArgument
+    InvalidRange, NoSuchKey, InvalidArgument, HTTPNoContent
 
 
 class ObjectController(Controller):
@@ -143,5 +143,6 @@ class ObjectController(Controller):
         except NoSuchKey:
             # expect to raise NoSuchBucket when the bucket doesn't exist
             req.get_container_info(self.app)
-            raise
+            # else -- it's gone! Success.
+            return HTTPNoContent()
         return resp

test/functional/s3api/test_object.py

@@ -139,6 +139,12 @@ class TestS3ApiObject(S3ApiBase):
         self.assertEqual(status, 204)
         self.assertCommonResponseHeaders(headers)
 
+        # DELETE Non-Existent Object
+        status, headers, body = \
+            self.conn.make_request('DELETE', self.bucket, 'does-not-exist')
+        self.assertEqual(status, 204)
+        self.assertCommonResponseHeaders(headers)
+
     def test_put_object_error(self):
         auth_error_conn = Connection(aws_secret_key='invalid')
         status, headers, body = \
@@ -238,11 +244,6 @@ class TestS3ApiObject(S3ApiBase):
         self.assertEqual(get_error_code(body), 'SignatureDoesNotMatch')
         self.assertEqual(headers['content-type'], 'application/xml')
 
-        status, headers, body = \
-            self.conn.make_request('DELETE', self.bucket, 'invalid')
-        self.assertEqual(get_error_code(body), 'NoSuchKey')
-        self.assertEqual(headers['content-type'], 'application/xml')
-
         status, headers, body = \
             self.conn.make_request('DELETE', 'invalid', obj)
         self.assertEqual(get_error_code(body), 'NoSuchBucket')

test/unit/common/middleware/s3api/test_multi_delete.py

@@ -17,7 +17,6 @@ import unittest
 from datetime import datetime
 from hashlib import md5
 
-from six.moves import urllib
 from swift.common import swob
 from swift.common.swob import Request
 
@@ -87,11 +86,14 @@ class TestS3ApiMultiDelete(S3ApiTestCase):
 
         elem = fromstring(body)
         self.assertEqual(len(elem.findall('Deleted')), 3)
-        _, path, _ = self.swift.calls_with_headers[-1]
-        path, query_string = path.split('?', 1)
-        self.assertEqual(path, '/v1/AUTH_test/bucket/Key3')
-        query = dict(urllib.parse.parse_qsl(query_string))
-        self.assertEqual(query['multipart-manifest'], 'delete')
+        self.assertEqual(self.swift.calls, [
+            ('HEAD', '/v1/AUTH_test/bucket'),
+            ('HEAD', '/v1/AUTH_test/bucket/Key1'),
+            ('DELETE', '/v1/AUTH_test/bucket/Key1'),
+            ('HEAD', '/v1/AUTH_test/bucket/Key2'),
+            ('HEAD', '/v1/AUTH_test/bucket/Key3'),
+            ('DELETE', '/v1/AUTH_test/bucket/Key3?multipart-manifest=delete'),
+        ])
 
     @s3acl
     def test_object_multi_DELETE_quiet(self):

test/unit/common/middleware/s3api/test_obj.py

@@ -767,13 +767,6 @@ class TestS3ApiObj(S3ApiTestCase):
                                        swob.HTTPServiceUnavailable)
         self.assertEqual(code, 'InternalError')
 
-        with patch(
-                'swift.common.middleware.s3api.s3request.get_container_info',
-                return_value={'status': 204}):
-            code = self._test_method_error('DELETE', '/bucket/object',
-                                           swob.HTTPNotFound)
-            self.assertEqual(code, 'NoSuchKey')
-
         with patch(
                 'swift.common.middleware.s3api.s3request.get_container_info',
                 return_value={'status': 404}):
@@ -809,11 +802,27 @@ class TestS3ApiObj(S3ApiTestCase):
 
         self.assertIn(('HEAD', '/v1/AUTH_test/bucket/object'),
                       self.swift.calls)
-        self.assertIn(('DELETE', '/v1/AUTH_test/bucket/object'),
-                      self.swift.calls)
+        self.assertEqual(('DELETE', '/v1/AUTH_test/bucket/object'),
+                         self.swift.calls[-1])
         _, path = self.swift.calls[-1]
         self.assertEqual(path.count('?'), 0)
 
+    @s3acl
+    def test_object_DELETE_missing(self):
+        self.swift.register('HEAD', '/v1/AUTH_test/bucket/object',
+                            swob.HTTPNotFound, {}, None)
+        req = Request.blank('/bucket/object',
+                            environ={'REQUEST_METHOD': 'DELETE'},
+                            headers={'Authorization': 'AWS test:tester:hmac',
+                                     'Date': self.get_date_header()})
+        status, headers, body = self.call_s3api(req)
+        self.assertEqual(status.split()[0], '204')
+
+        self.assertIn(('HEAD', '/v1/AUTH_test/bucket/object'),
+                      self.swift.calls)
+        self.assertNotIn(('DELETE', '/v1/AUTH_test/bucket/object'),
+                         self.swift.calls)
+
     @s3acl
     def test_slo_object_DELETE(self):
         self.swift.register('HEAD', '/v1/AUTH_test/bucket/object',