Split runtime from static configuration and use it for request context.

mig/shared/conf.py

@@ -20,7 +20,7 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #
 # -- END_HEADER ---
 #
@@ -32,17 +32,62 @@
 import os
 import sys
 
+from mig.shared.configuration import Configuration
 from mig.shared.defaults import MIG_ENV
 from mig.shared.fileio import unpickle
 
 
-def get_configuration_object(config_file=None, skip_log=False,
+class RuntimeConfiguration:
+    """A proxy object to be passed in-place of a Configuration which can be
+    extended with information relevant only at runtime.
+
+    Given Configuration objects are threaded into and through almost all
+    the necessary codepaths to make this information available, they are an
+    attractive place to put this - but a Configuration is currently loaded
+    from static per-site data.
+
+    Resolve this dichotomy with this class - a Configuration instance will
+    continue to represent the static data while an object that proxies its
+    attributes and thus is entirely drop-in compatible with it can be handed
+    to callers without being mixed in with the static data.
+    """
+
+    def __init__(self, configuration):
+        object.__setattr__(self, '_configuration', configuration)
+        object.__setattr__(self, '_context', {})
+
+    def __delattr__(self, attr):
+        return delattr(self._configuration, attr)
+
+    def __getattr__(self, attr):
+        return getattr(self._configuration, attr)
+
+    def __setattr__(self, attr, value):
+        return setattr(self._configuration, attr, value)
+
+    def context_get(self, context_key):
+        """Retrieve the context or a previously registered namespace.
+        """
+        return self._context.get(context_key, None)
+
+    def context_set(self, context_key, context_value):
+        """Attach a value as named namespace within the active configuration.
+        """
+        self._context[context_key] = context_value
+
+    @classmethod
+    def is_runtime_configuration(cls, obj):
+        """Is the given object a runtime configuration."""
+        return isinstance(obj, cls)
+
+
+def get_configuration_object(config_file=None,
+                             skip_log=False,
                              disable_auth_log=False):
     """Simple helper to call the general configuration init. Optional skip_log
     and disable_auth_log arguments are passed on to allow skipping the default
     log initialization and disabling auth log for unit tests.
     """
-    from mig.shared.configuration import Configuration
     if config_file:
         _config_file = config_file
     elif os.environ.get('MIG_CONF', None):
@@ -65,7 +110,7 @@
 
     configuration = Configuration(_config_file, False, skip_log,
                                   disable_auth_log)
-    return configuration
+    return RuntimeConfiguration(configuration)
 
 
 def get_resource_configuration(resource_home, unique_resource_name,
@@ -85,7 +130,7 @@
         return (True, resource_config)
 
 
 def get_resource_fields(resource_home, unique_resource_name, fields, logger):
     """Return a dictionary mapping fields to resource_config values.
     Missing fields are left out of the result dictionary.
     """
@@ -102,7 +147,7 @@
     return results
 
 
 def get_resource_exe(resource_config, exe_name, logger):
     for exe in resource_config['EXECONFIG']:
 
         # find the right exe entry
@@ -119,7 +164,7 @@
     return (False, msg)
 
 
 def get_resource_all_exes(resource_config, logger):
     msg = ''
     if 'EXECONFIG' not in resource_config:
         msg = 'No exe hosts configured!'
@@ -128,7 +173,7 @@
     return (True, resource_config['EXECONFIG'])
 
 
 def get_all_exe_names(unique_resource_name):
     exe_names = []
     conf = get_configuration_object()
     (status, resource_config) = \

tests/support/__init__.py

@@ -1,3 +1,3 @@
 #!/usr/bin/python
 # -*- coding: utf-8 -*-
 #
@@ -92,10 +92,10 @@
 
 # Exports to expose at the top level from the support library.
 
 from tests.support.assertover import AssertOver
 from tests.support.configsupp import FakeConfiguration
 from tests.support.loggersupp import FakeLogger, FakeLoggerChecker
 from tests.support.serversupp import make_wrapped_server
 
 
 # Basic global logging configuration for testing
@@ -210,16 +210,18 @@
     @staticmethod
     def _make_configuration_instance(testcase, configuration_to_make):
         if configuration_to_make == 'fakeconfig':
-            return FakeConfiguration(logger=testcase.logger)
+            fake_configuration = FakeConfiguration(logger=testcase.logger)
+            from mig.shared.conf import RuntimeConfiguration
+            return RuntimeConfiguration(fake_configuration)
         elif configuration_to_make == 'testconfig':
             from mig.shared.conf import get_configuration_object
-            configuration = get_configuration_object(skip_log=True, 
+            configuration = get_configuration_object(skip_log=True,
                                                      disable_auth_log=True)
             configuration.logger = testcase.logger
             return configuration
         else:
             raise AssertionError(
                 "MigTestCase: unknown configuration %r" % (configuration_to_make,))
 
     def _provide_configuration(self):
         return 'unspecified'
@@ -291,7 +293,7 @@
 
     def assertFileContentIdentical(self, file_actual, file_expected):
         """Make sure file_actual and file_expected are identical"""
         with io.open(file_actual) as f_actual, io.open(file_expected) as f_expected:
             lhs = f_actual.readlines()
             rhs = f_expected.readlines()
             different_lines = list(difflib.unified_diff(rhs, lhs))
@@ -359,7 +361,7 @@
         Note that this method, along with a number of others, are defined in
         the user portion of the test support libraries.
         """
         return UserAssertMixin._provision_test_user(testcase, distinguished_name)
 
 
 def is_path_within(path, start=None, _msg=None):
@@ -367,7 +369,7 @@
     try:
         assert os.path.isabs(path), _msg
         relative = os.path.relpath(path, start=start)
     except:
         return False
     return not relative.startswith('..')
 

tests/test_mig_shared_conf.py

@@ -0,0 +1,54 @@
+# -*- coding: utf-8 -*-
+#
+# --- BEGIN_HEADER ---
+#
+# test_mig_shared_configuration - unit test of configuration
+# Copyright (C) 2003-2026  The MiG Project by the Science HPC Center at UCPH
+#
+# This file is part of MiG.
+#
+# MiG is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# MiG is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
+# USA.
+#
+# --- END_HEADER ---
+#
+
+"""Unit tests for shared conf"""
+
+import inspect
+import os
+import unittest
+
+from tests.support import MigTestCase, TEST_DATA_DIR, PY2, testmain
+from tests.support.fixturesupp import FixtureAssertMixin
+
+from mig.shared.conf import Configuration, \
+                            RuntimeConfiguration, \
+                            get_configuration_object
+
+
+class MigSharedConf(MigTestCase):
+    """Coverage of module methods."""
+
+    def test_get_configuration_object_returns_runtime_configuration(self):
+        configuration = get_configuration_object(skip_log=True,
+                                                 disable_auth_log=True)
+        self.assertIsInstance(configuration, RuntimeConfiguration)
+        static_configuration = configuration._configuration
+        self.assertIsInstance(static_configuration, Configuration)
+
+
+if __name__ == '__main__':
+    testmain()

tests/test_support.py

@@ -1,3 +1,3 @@
 # -*- coding: utf-8 -*-
 #
 # --- BEGIN_HEADER ---
@@ -35,8 +35,7 @@
 from tests.support import MigTestCase, PY2, testmain, temppath, \
     AssertOver, FakeConfiguration
 
-from mig.shared.conf import get_configuration_object
-from mig.shared.configuration import Configuration
+from mig.shared.conf import get_configuration_object, RuntimeConfiguration
 
 
 class InstrumentedAssertOver(AssertOver):
@@ -81,7 +80,7 @@
             self.configuration
         theexception = raised.exception
         self.assertEqual(str(theexception),
             "configuration access but testcase did not request it")
 
     @unittest.skipIf(PY2, "Python 3 only")
     def test_unclosed_files_are_recorded(self):
@@ -143,8 +142,9 @@
 
     def test_provides_a_fake_configuration(self):
         configuration = self.configuration
-
-        self.assertIsInstance(configuration, FakeConfiguration)
+        self.assertIsInstance(configuration, RuntimeConfiguration)
+        static_configuration = configuration._configuration
+        self.assertIsInstance(static_configuration, FakeConfiguration)
 
     def test_provides_a_fake_configuration_for_the_duration_of_the_test(self):
         c1 = self.configuration
@@ -165,7 +165,7 @@
         configuration = self.configuration
 
         # check we have a real config object
-        self.assertIsInstance(configuration, Configuration)
+        self.assertIsInstance(configuration, RuntimeConfiguration)
         # check for having loaded a config file from a test config dir
         config_file_path_parts = configuration.config_file.split(os.path.sep)
         config_file_path_parts.pop()  # discard file part