Import gssapi lazily for GSSAPI

kafka/sasl/gssapi.py

@@ -2,15 +2,6 @@
 
 import struct
 
-# needed for SASL_GSSAPI authentication:
-try:
-    import gssapi
-    from gssapi.raw.misc import GSSError
-except (ImportError, OSError):
-    #no gssapi available, will disable gssapi mechanism
-    gssapi = None
-    GSSError = None
-
 from kafka.sasl.abc import SaslMechanism
 
 
@@ -23,6 +14,10 @@ class SaslMechanismGSSAPI(SaslMechanism):
     SASL_QOP_AUTH_CONF = 4
 
     def __init__(self, **config):
+        try:
+            import gssapi
+        except (ImportError, OSError):
+            gssapi = None
         assert gssapi is not None, 'GSSAPI lib not available'
         if 'sasl_kerberos_name' not in config and 'sasl_kerberos_service_name' not in config:
             raise ValueError('sasl_kerberos_service_name or sasl_kerberos_name required for GSSAPI sasl configuration')

test/sasl/test_gssapi.py

@@ -1,10 +1,14 @@
 from __future__ import absolute_import
 
+import sys
+
 try:
     from unittest import mock
 except ImportError:
     import mock
 
+import pytest
+
 from kafka.sasl import get_sasl_mechanism
 import kafka.sasl.gssapi
 
@@ -23,9 +27,10 @@ def mocked_message_wrapper(msg, *args):
         return wrapped
     client_ctx.unwrap.side_effect = mocked_message_wrapper
     client_ctx.wrap.side_effect = mocked_message_wrapper
-    kafka.sasl.gssapi.gssapi = mock.Mock()
-    kafka.sasl.gssapi.gssapi.SecurityContext.return_value = client_ctx
-    gssapi = get_sasl_mechanism('GSSAPI')(**config)
+    gssapi_mock = mock.Mock()
+    gssapi_mock.SecurityContext.return_value = client_ctx
+    with mock.patch.dict(sys.modules, {'gssapi': gssapi_mock}):
+        gssapi = get_sasl_mechanism('GSSAPI')(**config)
     assert isinstance(gssapi, kafka.sasl.gssapi.SaslMechanismGSSAPI)
     client_ctx.step.assert_called_with(None)
 
@@ -40,3 +45,9 @@ def mocked_message_wrapper(msg, *args):
 
     assert gssapi.is_done()
     assert gssapi.is_authenticated()
+
+
+def test_gssapi_unavailable():
+    with mock.patch.dict(sys.modules, {'gssapi': None}):
+        with pytest.raises(AssertionError, match='GSSAPI lib not available'):
+            kafka.sasl.gssapi.SaslMechanismGSSAPI(sasl_kerberos_service_name='bar')