Fixed Channel to handle the case where ssl module is not available, c…

…loses #194

grpclib/client.py

@@ -658,10 +658,10 @@ def __init__(
  if port is None:
  port = 50051
 
- if ssl is not None and _ssl is None:
- raise RuntimeError('SSL is not supported.')
-
- if ssl is True:
+ if _ssl is None:
+ if ssl is not None:
+ raise RuntimeError('SSL is not supported')
+ elif ssl is True:
  ssl = self._get_default_ssl_context()
  elif isinstance(ssl, _ssl.DefaultVerifyPaths):
  ssl = self._get_default_ssl_context(verify_paths=ssl)

tests/test_client_channel.py

@@ -8,6 +8,7 @@
 import certifi
 from h2.connection import H2Connection
 
+import grpclib.client
 from grpclib.client import Channel, Handler
 from grpclib.config import Configuration
 from grpclib.protocol import H2Protocol
@@ -95,3 +96,11 @@ def test_default_verify_paths():
  po.assert_called_once_with(tf, td, None)
  assert default_verify_paths.openssl_cafile_env == "SSL_CERT_FILE"
  assert default_verify_paths.openssl_capath_env == "SSL_CERT_DIR"
+
+
+def test_no_ssl_support():
+ with patch.object(grpclib.client, "_ssl", None):
+ Channel()
+ with pytest.raises(RuntimeError) as err:
+ Channel(ssl=True)
+ err.match("SSL is not supported")