[entropy.transceivers] do not mandate to test the connection on __init__()

Besides making context support complex, it doesn't do any good because
connectivity errors are generally transient anyway (apart from misconfigs).

lib/entropy/transceivers/uri_handlers/plugins/interfaces/ftp_plugin.py

@@ -71,11 +71,6 @@ class EntropyFtpUriHandler(EntropyUriHandler):
 
         self._init_vars()
 
-        # as documentation suggests
-        # test out connection first
-        self._connect()
-        self._disconnect()
-
     def __enter__(self):
         pass # self.__connect_if_not()
 

lib/entropy/transceivers/uri_handlers/plugins/interfaces/ssh_plugin.py

@@ -63,32 +63,12 @@ class EntropySshUriHandler(EntropyUriHandler):
         self.__user, self.__port, self.__dir = self.__extract_scp_data(
             self._uri)
 
-        # as documentation suggests
-        # test out connection first
-        self.__test_connection()
-
     def __enter__(self):
         pass
 
     def __exit__(self, exc_type, exc_value, traceback):
         self.close()
 
-    def __test_connection(self):
-        tries = 5
-        while tries:
-            tries -= 1
-            try:
-                sock = self._socket.create_connection(
-                    (self.__host, self.__port), 5)
-                sock.close()
-                return
-            except self._socket.error:
-                time.sleep(5)
-                continue
-
-        raise TransceiverConnectionError("cannot connect to %s on port %s" % (
-            self.__host, self.__port,))
-
     def __extract_scp_data(self, uri):
 
         no_ssh_split = uri.split("ssh://")[-1]

lib/entropy/transceivers/uri_handlers/skel.py

@@ -30,9 +30,6 @@ class EntropyUriHandler(TextInterface):
     def __init__(self, uri):
         """
         EntropyUriHandler constructor.
-        When constructor is called, instance should perform a connection and
-        permissions check and raise TransceiverConnectionError in case
-        of issues.
 
         @param uri: URI to handle
         @type uri: string