Allow to disable printing expected runtime errors in SSHAuth (#49)

When users on a node are not prepared yet, it is expected
to get wrong authorization exception like this:

ssh_client.py:147 -- Connection using stored authentication info failed!
Traceback (most recent call last):
...
BadAuthenticationType: ('Bad authentication type', [u'publickey']) (allowed_types=[u'publickey'])

- new parameter to SSHClient 'verbose' allows to disable printing
  such errors during waiting for ssh access.

doc/source/SSHClient.rst

@@ -24,6 +24,8 @@ API: SSHClient and SSHAuth.
         :type private_keys: ``typing.Optional[typing.Iterable[paramiko.RSAKey]]``
         :param auth: credentials for connection
         :type auth: typing.Optional[SSHAuth]
+        :param verbose: show additional error/warning messages
+        :type verbose: bool
 
     .. note:: auth has priority over username/password/private_keys
 

exec_helpers/_ssh_client_base.py

@@ -116,6 +116,7 @@ def __call__(
         password=None,  # type: typing.Optional[str]
         private_keys=None,  # type: typing.Optional[typing.Iterable[paramiko.RSAKey]]
         auth=None,  # type: typing.Optional[ssh_auth.SSHAuth]
+        verbose=True,  # type: bool
     ):  # type: (...) -> SSHClientBase
         """Main memorize method: check for cached instance and return it.
 
@@ -125,6 +126,7 @@ def __call__(
         :type password: str
         :type private_keys: list
         :type auth: ssh_auth.SSHAuth
+        :type verbose: bool
         :rtype: SSHClient
         """
         if (host, port) in cls.__cache:
@@ -160,7 +162,7 @@ def __call__(
         ).__call__(
             host=host, port=port,
             username=username, password=password, private_keys=private_keys,
-            auth=auth)
+            auth=auth, verbose=verbose)
         cls.__cache[(ssh.hostname, ssh.port)] = ssh
         return ssh
 
@@ -195,7 +197,7 @@ class SSHClientBase(six.with_metaclass(_MemorizedSSH, _api.ExecHelper)):
 
     __slots__ = (
         '__hostname', '__port', '__auth', '__ssh', '__sftp',
-        '__sudo_mode', '__keepalive_mode',
+        '__sudo_mode', '__keepalive_mode', '__verbose',
     )
 
     class __get_sudo(object):
@@ -279,6 +281,7 @@ def __init__(
         password=None,  # type: typing.Optional[str]
         private_keys=None,  # type: typing.Optional[typing.Iterable[paramiko.RSAKey]]
         auth=None,  # type: typing.Optional[ssh_auth.SSHAuth]
+        verbose=True,  # type: bool
     ):  # type: (...) -> None
         """SSHClient helper.
 
@@ -294,6 +297,8 @@ def __init__(
         :type private_keys: typing.Optional[typing.Iterable[paramiko.RSAKey]]
         :param auth: credentials for connection
         :type auth: typing.Optional[ssh_auth.SSHAuth]
+        :param verbose: show additional error/warning messages
+        :type verbose: bool
 
         .. note:: auth has priority over username/password/private_keys
         """
@@ -310,6 +315,7 @@ def __init__(
 
         self.__sudo_mode = False
         self.__keepalive_mode = True
+        self.__verbose = verbose
 
         self.__ssh = paramiko.SSHClient()
         self.__ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
@@ -400,7 +406,7 @@ def __connect(self):
             self.auth.connect(
                 client=self.__ssh,
                 hostname=self.hostname, port=self.port,
-                log=True)
+                log=self.__verbose)
 
     def __connect_sftp(self):
         """SFTP connection opener."""

exec_helpers/_ssh_client_base.pyi

@@ -17,7 +17,8 @@ class _MemorizedSSH(type):
         username: typing.Optional[str]=...,
         password: typing.Optional[str]=...,
         private_keys: typing.Optional[typing.Iterable[paramiko.RSAKey]]=...,
-        auth: typing.Optional[ssh_auth.SSHAuth]=...
+        auth: typing.Optional[ssh_auth.SSHAuth]=...,
+        verbose: bool=...
     ) -> SSHClientBase: ...
 
     @classmethod
@@ -37,7 +38,8 @@ class SSHClientBase(_api.ExecHelper, metaclass=_MemorizedSSH):
         username: typing.Optional[str]=...,
         password: typing.Optional[str]=...,
         private_keys: typing.Optional[typing.Iterable[paramiko.RSAKey]]=...,
-        auth: typing.Optional[ssh_auth.SSHAuth]=...
+        auth: typing.Optional[ssh_auth.SSHAuth]=...,
+        verbose: bool=...
     ) -> None: ...
 
     @property

test/test_ssh_client_init.py

@@ -759,3 +759,21 @@ def test_025_init_memorize_reconnect(self, execute, client, policy, logger):
         exec_helpers.SSHClient(host=host)
         client.assert_called_once()
         policy.assert_called_once()
+
+    @mock.patch('time.sleep', autospec=True)
+    def test_026_init_auth_impossible_key_no_verbose(
+            self, sleep, client, policy, logger):
+        connect = mock.Mock(side_effect=paramiko.AuthenticationException)
+
+        _ssh = mock.Mock()
+        _ssh.attach_mock(connect, 'connect')
+        client.return_value = _ssh
+
+        with self.assertRaises(paramiko.AuthenticationException):
+            exec_helpers.SSHClient(
+                host=host,
+                auth=exec_helpers.SSHAuth(key=gen_private_keys(1).pop()),
+                verbose=False
+            )
+
+        logger.assert_not_called()