Make service_account_email public, read-only

google/auth/app_engine.py

@@ -86,6 +86,14 @@ def refresh(self, request):
 
         self.token, self.expiry = token, expiry
 
+    @property
+    def service_account_email(self):
+        """The service account email."""
+        if self._service_account_id is not None:
+            return self._service_account_id
+        else:
+            return app_identity.get_service_account_name()
+
     @property
     def requires_scopes(self):
         """Checks if the credentials requires scopes.

google/auth/compute_engine/credentials.py

@@ -92,6 +92,15 @@ def refresh(self, request):
         except exceptions.TransportError as exc:
             raise exceptions.RefreshError(exc)
 
+    @property
+    def service_account_email(self):
+        """The service account email.
+
+        .. Note: This is not guarenteed to be set until :meth`refresh` has been
+            called.
+        """
+        return self._service_account_email
+
     @property
     def requires_scopes(self):
         """False: Compute Engine credentials can not be scoped."""

google/oauth2/service_account.py

@@ -231,6 +231,11 @@ def to_jwt_credentials(self):
             issuer=self._service_account_email,
             subject=self._service_account_email)
 
+    @property
+    def service_account_email(self):
+        """The service account email."""
+        return self._service_account_email
+
     @property
     def requires_scopes(self):
         """Checks if the credentials requires scopes.

tests/compute_engine/test_credentials.py

@@ -34,6 +34,8 @@ def test_default_state(self):
         assert not self.credentials.expired
         # Scopes aren't needed
         assert not self.credentials.requires_scopes
+        # Service account email hasn't been populated
+        assert self.credentials.service_account_email == 'default'
 
     @mock.patch(
         'google.auth._helpers.utcnow', return_value=datetime.datetime.min)
@@ -58,7 +60,7 @@ def test_refresh_success(self, get_mock, now_mock):
             datetime.datetime.min + datetime.timedelta(seconds=500))
 
         # Check the credential info
-        assert (self.credentials._service_account_email ==
+        assert (self.credentials.service_account_email ==
                 '[email protected]')
         assert self.credentials._scopes == ['one', 'two']
 

tests/oauth2/test_service_account.py

@@ -63,7 +63,7 @@ def test_from_service_account_info(self):
 
         assert (credentials._signer.key_id ==
                 SERVICE_ACCOUNT_INFO['private_key_id'])
-        assert (credentials._service_account_email ==
+        assert (credentials.service_account_email ==
                 SERVICE_ACCOUNT_INFO['client_email'])
         assert credentials._token_uri == SERVICE_ACCOUNT_INFO['token_uri']
 
@@ -77,8 +77,8 @@ def test_from_service_account_info_args(self):
             info, scopes=scopes, subject=subject,
             additional_claims=additional_claims)
 
+        assert credentials.service_account_email == info['client_email']
         assert credentials._signer.key_id == info['private_key_id']
-        assert credentials._service_account_email == info['client_email']
         assert credentials._token_uri == info['token_uri']
         assert credentials._scopes == scopes
         assert credentials._subject == subject
@@ -90,8 +90,8 @@ def test_from_service_account_file(self):
         credentials = service_account.Credentials.from_service_account_file(
             SERVICE_ACCOUNT_JSON_FILE)
 
+        assert credentials.service_account_email == info['client_email']
         assert credentials._signer.key_id == info['private_key_id']
-        assert credentials._service_account_email == info['client_email']
         assert credentials._token_uri == info['token_uri']
 
     def test_from_service_account_file_args(self):
@@ -104,8 +104,8 @@ def test_from_service_account_file_args(self):
             SERVICE_ACCOUNT_JSON_FILE, subject=subject,
             scopes=scopes, additional_claims=additional_claims)
 
+        assert credentials.service_account_email == info['client_email']
         assert credentials._signer.key_id == info['private_key_id']
-        assert credentials._service_account_email == info['client_email']
         assert credentials._token_uri == info['token_uri']
         assert credentials._scopes == scopes
         assert credentials._subject == subject

tests/test_app_engine.py

@@ -70,6 +70,23 @@ def test_with_scopes(self, app_identity_mock):
         assert scoped_credentials.has_scopes(['email'])
         assert not scoped_credentials.requires_scopes
 
+    def test_service_account_email_implicit(self, app_identity_mock):
+        app_identity_mock.get_service_account_name.return_value = (
+            mock.sentinel.service_account_email)
+        credentials = app_engine.Credentials()
+
+        assert (credentials.service_account_email ==
+                mock.sentinel.service_account_email)
+        assert app_identity_mock.get_service_account_name.called
+
+    def test_service_account_email_explicit(self, app_identity_mock):
+        credentials = app_engine.Credentials(
+            service_account_id=mock.sentinel.service_account_email)
+
+        assert (credentials.service_account_email ==
+                mock.sentinel.service_account_email)
+        assert not app_identity_mock.get_service_account_name.called
+
     @mock.patch(
         'google.auth._helpers.utcnow',
         return_value=datetime.datetime.min)