Moving user agent to client class from _helpers module.

This allows a user to over-ride rather than digging into a
private module.

gcloud_bigtable/_helpers.py

@@ -44,7 +44,6 @@
 # See https://gist.github.com/dhermes/bbc5b7be1932bfffae77
 # for appropriate values on other systems.
 SSL_CERT_FILE = '/etc/ssl/certs/ca-certificates.crt'
-USER_AGENT = 'gcloud-bigtable-python'
 
 
 class MetadataTransformer(object):
@@ -57,13 +56,14 @@ class MetadataTransformer(object):
 
     def __init__(self, client):
         self._credentials = client.credentials
+        self._user_agent = client.user_agent
 
     def __call__(self, ignored_val):
         """Adds authorization header to request metadata."""
         access_token = self._credentials.get_access_token().access_token
         return [
             ('Authorization', 'Bearer ' + access_token),
-            ('User-agent', USER_AGENT),
+            ('User-agent', self._user_agent),
         ]
 
 

gcloud_bigtable/client.py

@@ -58,6 +58,7 @@
 """Environment variable used to provide an implicit project ID."""
 
 DEFAULT_TIMEOUT_SECONDS = 10
+DEFAULT_USER_AGENT = 'gcloud-bigtable-python'
 
 
 def _project_id_from_environment():
@@ -174,6 +175,10 @@ class Client(object):
                   interact with the Cluster Admin or Table Admin APIs. This
                   requires the ``ADMIN_SCOPE``. Defaults to ``False``.
 
+    :type user_agent: string
+    :param user_agent: (Optional) The user agent to be used with API request.
+                       Defaults to ``DEFAULT_USER_AGENT``.
+
     :type timeout_seconds: integer
     :param timeout_seconds: Number of seconds for request time-out. If not
                             passed, defaults to ``DEFAULT_TIMEOUT_SECONDS``.
@@ -183,7 +188,7 @@ class Client(object):
     """
 
     def __init__(self, credentials=None, project_id=None,
-                 read_only=False, admin=False,
+                 read_only=False, admin=False, user_agent=DEFAULT_USER_AGENT,
                  timeout_seconds=DEFAULT_TIMEOUT_SECONDS):
         if read_only and admin:
             raise ValueError('A read-only client cannot also perform'
@@ -203,6 +208,7 @@ def __init__(self, credentials=None, project_id=None,
 
         self._credentials = credentials.create_scoped(scopes)
         self._project_id = _determine_project_id(project_id)
+        self.user_agent = user_agent
         self.timeout_seconds = timeout_seconds
 
     @classmethod

gcloud_bigtable/test__helpers.py

@@ -33,18 +33,21 @@ def test_constructor(self):
         scoped_creds = object()
         credentials = _MockWithAttachedMethods(scoped_creds)
         project_id = 'PROJECT_ID'
-        client = Client(credentials, project_id=project_id)
+        user_agent = 'USER_AGENT'
+        client = Client(credentials, project_id=project_id,
+                        user_agent=user_agent)
         transformer = self._makeOne(client)
         self.assertTrue(transformer._credentials is scoped_creds)
+        self.assertEqual(transformer._user_agent, user_agent)
         self.assertEqual(credentials._called, [
             ('create_scoped', ([DATA_SCOPE],), {}),
         ])
 
     def test___call__(self):
         from gcloud_bigtable._testing import _MockWithAttachedMethods
-        from gcloud_bigtable._helpers import USER_AGENT
         from gcloud_bigtable.client import Client
         from gcloud_bigtable.client import DATA_SCOPE
+        from gcloud_bigtable.client import DEFAULT_USER_AGENT
 
         access_token_expected = 'FOOBARBAZ'
 
@@ -62,7 +65,7 @@ class _ReturnVal(object):
             result,
             [
                 ('Authorization', 'Bearer ' + access_token_expected),
-                ('User-agent', USER_AGENT),
+                ('User-agent', DEFAULT_USER_AGENT),
             ])
         self.assertEqual(credentials._called, [
             ('create_scoped', ([DATA_SCOPE],), {}),

gcloud_bigtable/test_client.py

@@ -251,7 +251,8 @@ def _makeOne(self, *args, **kwargs):
         return self._getTargetClass()(*args, **kwargs)
 
     def _constructor_test_helper(self, expected_scopes, project_id=None,
-                                 admin=False, read_only=False):
+                                 read_only=False, admin=False,
+                                 user_agent=None):
         from gcloud_bigtable._testing import _MockCalled
         from gcloud_bigtable._testing import _MockWithAttachedMethods
         from gcloud_bigtable._testing import _Monkey
@@ -263,14 +264,16 @@ def _constructor_test_helper(self, expected_scopes, project_id=None,
         mock_determine_project_id = _MockCalled(determined_project_id)
         with _Monkey(MUT, _determine_project_id=mock_determine_project_id):
             client = self._makeOne(credentials, project_id=project_id,
-                                   admin=admin, read_only=read_only)
+                                   read_only=read_only, admin=admin,
+                                   user_agent=user_agent)
 
         self.assertTrue(client._credentials is scoped_creds)
         self.assertEqual(credentials._called, [
             ('create_scoped', (expected_scopes,), {}),
         ])
         self.assertTrue(client._project_id is determined_project_id)
         self.assertEqual(client.timeout_seconds, MUT.DEFAULT_TIMEOUT_SECONDS)
+        self.assertEqual(client.user_agent, user_agent)
         mock_determine_project_id.check_called(self, [(project_id,)])
 
     def test_constructor_default(self):
@@ -287,6 +290,7 @@ def test_constructor_default(self):
 
         self.assertEqual(client.project_id, PROJECT_ID)
         self.assertTrue(client._credentials is scoped_creds)
+        self.assertEqual(client.user_agent, MUT.DEFAULT_USER_AGENT)
         self.assertEqual(mock_creds_class._called,
                          [('get_application_default', (), {})])
         expected_scopes = [MUT.DATA_SCOPE]
@@ -304,6 +308,12 @@ def test_constructor_with_explicit_project_id(self):
         expected_scopes = [MUT.DATA_SCOPE]
         self._constructor_test_helper(expected_scopes, project_id=PROJECT_ID)
 
+    def test_constructor_with_explicit_user_agent(self):
+        from gcloud_bigtable import client as MUT
+        user_agent = 'USER_AGENT'
+        expected_scopes = [MUT.DATA_SCOPE]
+        self._constructor_test_helper(expected_scopes, user_agent=user_agent)
+
     def test_constructor_with_admin(self):
         from gcloud_bigtable import client as MUT
         expected_scopes = [MUT.DATA_SCOPE, MUT.ADMIN_SCOPE]