Enabling direct_client users to overwrite X-Timestamp

Changing gen_headers to set User-Agent if not already added
and set x-timestamp by default if it's not already set nor
it's requested not to be put.

Change-Id: Ied073778cf5d34ddcb2f5af59d5b762e51c9b11f
Partial-Bug: 1757250

swift/common/direct_client.py

@@ -177,11 +177,21 @@ def _get_direct_account_container(path, stype, node, part,
     return resp_headers, json.loads(resp.read().decode('ascii'))
 
 
-def gen_headers(hdrs_in=None, add_ts=False, add_user_agent=True):
+def gen_headers(hdrs_in=None, add_ts=True):
+    """
+    Get the headers ready for a request. All requests should have a User-Agent
+    string, but if one is passed in don't over-write it. Not all requests will
+    need an X-Timestamp, but if one is passed in do not over-write it.
+
+    :param headers: dict or None, base for HTTP headers
+    :param add_ts: boolean, should be True for any "unsafe" HTTP request
+
+    :returns: HeaderKeyDict based on headers and ready for the request
+    """
     hdrs_out = HeaderKeyDict(hdrs_in) if hdrs_in else HeaderKeyDict()
-    if add_ts:
+    if add_ts and 'X-Timestamp' not in hdrs_out:
         hdrs_out['X-Timestamp'] = Timestamp.now().internal
-    if add_user_agent:
+    if 'user-agent' not in hdrs_out:
         hdrs_out['User-Agent'] = 'direct-client %s' % os.getpid()
     return hdrs_out
 
@@ -332,8 +342,7 @@ def direct_put_container(node, part, account, container, conn_timeout=5,
 
     lower_headers = set(k.lower() for k in headers)
     headers_out = gen_headers(headers,
-                              add_ts='x-timestamp' not in lower_headers,
+                              add_ts='x-timestamp' not in lower_headers)
-                              add_user_agent='user-agent' not in lower_headers)
     path = _make_path(account, container)
     _make_req(node, part, 'PUT', path, headers_out, 'Container', conn_timeout,
               response_timeout, contents=contents,

test/unit/common/test_direct_client.py

@@ -131,25 +131,47 @@ class TestDirectClient(unittest.TestCase):
     def test_gen_headers(self):
         stub_user_agent = 'direct-client %s' % os.getpid()
 
-        headers = direct_client.gen_headers()
+        headers = direct_client.gen_headers(add_ts=False)
         self.assertEqual(headers['user-agent'], stub_user_agent)
         self.assertEqual(1, len(headers))
 
         now = time.time()
-        headers = direct_client.gen_headers(add_ts=True)
+        headers = direct_client.gen_headers()
         self.assertEqual(headers['user-agent'], stub_user_agent)
         self.assertTrue(now - 1 < Timestamp(headers['x-timestamp']) < now + 1)
         self.assertEqual(headers['x-timestamp'],
                          Timestamp(headers['x-timestamp']).internal)
         self.assertEqual(2, len(headers))
 
-        headers = direct_client.gen_headers(hdrs_in={'foo-bar': '47'})
+        headers = direct_client.gen_headers(hdrs_in={'x-timestamp': '15'})
+        self.assertEqual(headers['x-timestamp'], '15')
         self.assertEqual(headers['user-agent'], stub_user_agent)
-        self.assertEqual(headers['foo-bar'], '47')
         self.assertEqual(2, len(headers))
 
-        headers = direct_client.gen_headers(hdrs_in={'user-agent': '47'})
+        headers = direct_client.gen_headers(hdrs_in={'foo-bar': '63'})
         self.assertEqual(headers['user-agent'], stub_user_agent)
+        self.assertEqual(headers['foo-bar'], '63')
+        self.assertTrue(now - 1 < Timestamp(headers['x-timestamp']) < now + 1)
+        self.assertEqual(headers['x-timestamp'],
+                         Timestamp(headers['x-timestamp']).internal)
+        self.assertEqual(3, len(headers))
+
+        hdrs_in = {'foo-bar': '55'}
+        headers = direct_client.gen_headers(hdrs_in, add_ts=False)
+        self.assertEqual(headers['user-agent'], stub_user_agent)
+        self.assertEqual(headers['foo-bar'], '55')
+        self.assertEqual(2, len(headers))
+
+        headers = direct_client.gen_headers(hdrs_in={'user-agent': '32'})
+        self.assertEqual(headers['user-agent'], '32')
+        self.assertTrue(now - 1 < Timestamp(headers['x-timestamp']) < now + 1)
+        self.assertEqual(headers['x-timestamp'],
+                         Timestamp(headers['x-timestamp']).internal)
+        self.assertEqual(2, len(headers))
+
+        hdrs_in = {'user-agent': '47'}
+        headers = direct_client.gen_headers(hdrs_in, add_ts=False)
+        self.assertEqual(headers['user-agent'], '47')
         self.assertEqual(1, len(headers))
 
         for policy in POLICIES:
@@ -570,7 +592,7 @@ class TestDirectClient(unittest.TestCase):
 
         self.assertEqual(conn.req_headers['user-agent'], self.user_agent)
         self.assertEqual('bar', conn.req_headers.get('x-foo'))
-        self.assertNotIn('x-timestamp', conn.req_headers)
+        self.assertIn('x-timestamp', conn.req_headers)
         self.assertEqual(headers, resp)
 
     def test_direct_head_object_error(self):