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()
 
@@ -48,7 +55,7 @@
 try:
     # import the env
     SAVED_ENV = copy.deepcopy(os.environ)
-    console = GSSAPIConsole(mech_cls, realm_args=realm_args)
+    console = GSSAPIConsole(mech_cls, realm_args=realm_args, attach=PARSED_ARGS.attach)
     for k, v in console.realm.env.items():
         os.environ[k] = v
 
@@ -58,6 +65,8 @@
         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')
@@ -57,9 +63,14 @@ def stop(self):
     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,
@@ -70,4 +81,5 @@ def interact(self, banner=None):
         if banner is None:
             banner = self.banner_text
 
-        super(GSSAPIConsole, self).interact(banner)
+        # Python 2.7 uses old-style classes :-(
+        code.InteractiveConsole.interact(self, banner)

gssapi_console/drivers.py

@@ -1,3 +1,4 @@
+import os
 import sys
 
 
@@ -9,6 +10,12 @@ def create_realm(self, realm_args):
         return None
 
     def destroy_realm(self, realm):
+        pass
+
+    def attach_to_realm(self, identifier, realm_args={}):
+        pass
+
+    def identifier(self, realm):
         return None
 
 
@@ -25,3 +32,9 @@ def create_realm(self, realm_args):
 
     def destroy_realm(self, realm):
         realm.stop()
+
+    def attach_to_realm(self, identifier, realm_args={}):
+        return self._k5test.K5Realm(existing=identifier, **realm_args)
+
+    def identifier(self, realm):
+        return realm.tmpdir