Support attaching to an existing session

This commit adds support for attaching to an existing session.
To do so, use the '-a' or '--attach' flag with the session identifier
printed out in the gssapi-console banner (for example, the identifier
for the krb5 mech is the tmp directory path).

Author: DirectXMan12

gssapi-console.py

@@ -2,6 +2,8 @@
 
 # interactive console with easy access to krb5 test harness stuff
 
+from __future__ import print_function
+
 import argparse
 import os
 import sys
@@ -25,6 +27,11 @@
 parser.add_argument('--mech', default='krb5',
                     help='Which environment to setup up '
                          '(supports krb5 [default])')
+parser.add_argument('-a, --attach', metavar='IDENTIFIER', nargs='?',
+                    default=None, dest='attach',
+                    help='Attach to an existing gssapi-console environment, '
+                         'indicated by IDENTIFIER.')
+                                       
 
 PARSED_ARGS = parser.parse_args()
 
@@ -43,7 +50,9 @@
              'GSSAPI console' % PARSED_ARGS.mech)
 
 mech_cls = mech_cls_loader.load()
-console = GSSAPIConsole(mech_cls, realm_args=realm_args)
+
+console = GSSAPIConsole(mech_cls, realm_args=realm_args,
+                        attach=PARSED_ARGS.attach)
 
 SAVED_ENV = None
 
@@ -59,6 +68,8 @@
         if not PARSED_ARGS.force_interactive:
             INTER = False
 
+        print('Session: {0}'.format(console.session))
+
         with open(PARSED_ARGS.file) as src:
             console.runsource(src.read(), src.name, 'exec')
 

gssapi_console/core.py

@@ -31,15 +31,21 @@
 Type "help", "copyright", "credits" or "license" for more information about Python.
 
 Functions for controlling the realm are available in `REALM`.
+Session: {session}
 Mechansim: {mech} ({driver}), Realm: {realm}, User: {user}, Host: {host}"""
 
 
 class GSSAPIConsole(code.InteractiveConsole):
-    def __init__(self, driver_cls, use_readline=True, realm_args={}, *args, **kwargs):
+    def __init__(self, driver_cls, use_readline=True, realm_args={},
+                 attach=None, *args, **kwargs):
         code.InteractiveConsole.__init__(self, *args, **kwargs)
 
         self._driver = driver_cls()
-        self.realm = self._driver.create_realm(realm_args)
+        if attach is None:
+            self.realm = self._driver.create_realm(realm_args)
+        else:
+            self.realm = self._driver.attach_to_realm(attach, realm_args)
+
         self.locals['REALM'] = self.realm
 
         self.runsource('import gssapi')
@@ -54,9 +60,14 @@ def __init__(self, driver_cls, use_readline=True, realm_args={}, *args, **kwargs
     def _add_readline(self):
         self.runsource(READLINE_SRC, '<readline setup>', 'exec')
 
+    @property
+    def session(self):
+        return self._driver.identifier(self.realm)
+
     @property
     def banner_text(self):
         return BANNER.format(ver=sys.version, platform=sys.platform,
+                             session=self.session,
                              mech=self._driver.MECH_NAME,
                              driver=self._driver.PROVIDER_NAME,
                              realm=self.realm.realm,

gssapi_console/drivers.py

@@ -1,3 +1,4 @@
+import os
 import sys
 
 
@@ -8,14 +9,26 @@ class GSSAPIConsoleDriver(object):
     def create_realm(self, realm_args):
         return None
 
+    def attach_to_realm(self, identifier, realm_args={}):
+        pass
+
+    def identifier(self, realm):
+        return None
+
 
 class Krb5Console(GSSAPIConsoleDriver):
     MECH_NAME = 'krb5'
     PROVIDER_NAME = 'MIT Kerberos 5'
 
     def __init__(self):
-        __import__('gssapi.tests.k5test')
-        self._k5test = sys.modules['gssapi.tests.k5test']
+        __import__('gssapi_console.k5test')
+        self._k5test = sys.modules['gssapi_console.k5test']
 
     def create_realm(self, realm_args):
         return self._k5test.K5Realm(**realm_args)
+
+    def attach_to_realm(self, identifier, realm_args={}):
+        return self._k5test.K5Realm(existing=identifier, **realm_args)
+
+    def identifier(self, realm):
+        return realm.tmpdir

gssapi_console/k5test/__init__.py

@@ -0,0 +1 @@
+from gssapi_console.k5test.core import K5Realm, KerberosTestCase  # noqa