Rules: New options replace_name to replace %{name} in attributes

If you use the regex feature of Rules/Defaults you may need the real name
of the matched entry in an attribute (for example home of POSIXUser).
You can now enable replace_name for rules or defaults and %{name} will be
replaces in the attribues of the Element before adding them to the target
entry.

This allows you to write something like that in Defaults to assing a default
home directory somewhere else to all users with unset home:

    <POSIXUser name='.*' home='/somewhere/%{name}'/>

8 files changed, 106 insertions, 2 deletions

diff --git a/doc/releases/1.4.0pre2.txt b/doc/releases/1.4.0pre2.txt
index a5c10777a..9ad64db4e 100644
--- a/doc/releases/1.4.0pre2.txt
+++ b/doc/releases/1.4.0pre2.txt
@@ -19,6 +19,7 @@ environments.
 
 * NagiosGen: Add bundles to configuration
 * HomeBrew: Initial add of plugin
+* Rules/Defaults: Add possibility to use name of entry in attributes
 
 backwards-incompatible user-facing changes
 ------------------------------------------
diff --git a/doc/server/plugins/generators/rules.txt b/doc/server/plugins/generators/rules.txt
index e4f47c2bf..7aeec6990 100644
--- a/doc/server/plugins/generators/rules.txt
+++ b/doc/server/plugins/generators/rules.txt
@@ -512,3 +512,23 @@ you'd have to explicitly specify ``<Service name="bcfg2.*".../>``.
 
 Note that only one Rule can apply to any abstract entry, so you cannot
 specify multiple regexes to match the same rule.
+
+Replacing the name of the Entry in Attributes
+=============================================
+
+If you are using regular expressions to match the abstract configuration
+entries, you may need the concrete name of the entry in some attributes.
+To use this feature, you have to enable it. It is only useful, if used
+together with regex matching. ::
+
+    [rules]
+    regex = yes
+    replace_name = yes
+
+You now can write something like that in your xml file:
+
+.. code-block:: xml
+
+    <POSIXUser name='.*' home='/somewhere/%{name}'/>
+
+``%{name}`` will be correctly replaced with the username for each POSIXUser.
diff --git a/doc/server/plugins/structures/defaults.txt b/doc/server/plugins/structures/defaults.txt
index 58b9feddb..9d37b8e64 100644
--- a/doc/server/plugins/structures/defaults.txt
+++ b/doc/server/plugins/structures/defaults.txt
@@ -29,3 +29,10 @@ on Fedora 15 and the ``chkconfig`` tool on Fedora 14, you could do::
 If you were to specify a ``type`` attribute for a Service entry in
 Rules (or a ``type`` attribute for a BoundService entry in Bundler),
 that would take precendence over the default.
+
+Like :ref:`server-plugins-generators-rules`, Defaults can also replace
+``%{name}`` in attributes with the real name of the entry. To enable this,
+add the following setting to ``bcfg2.conf``::
+
+    [defaults]
+    replace_name = yes
diff --git a/src/lib/Bcfg2/Server/Plugin/helpers.py b/src/lib/Bcfg2/Server/Plugin/helpers.py
index 3b62a3217..6b521dfd6 100644
--- a/src/lib/Bcfg2/Server/Plugin/helpers.py
+++ b/src/lib/Bcfg2/Server/Plugin/helpers.py
@@ -1064,6 +1064,20 @@ class PrioDir(Plugin, Generator, XMLDirectoryBacked):
                     data = candidate
                     break
 
+        self._apply(entry, data)
+
+    def _apply(self, entry, data):
+        """ Apply all available values from data onto entry. This
+        sets the available attributes (for all attribues unset in
+        the entry), adds all children and copies the text from data
+        to entry.
+
+        :param entry: The entry to apply the changes
+        :type entry: lxml.etree._Element
+        :param data: The entry to get the data from
+        :type data: lxml.etree._Element
+        """
+
         if data.text is not None and data.text.strip() != '':
             entry.text = data.text
         for item in data.getchildren():
diff --git a/src/lib/Bcfg2/Server/Plugins/Defaults.py b/src/lib/Bcfg2/Server/Plugins/Defaults.py
index 79e2ca0e2..2242e3825 100644
--- a/src/lib/Bcfg2/Server/Plugins/Defaults.py
+++ b/src/lib/Bcfg2/Server/Plugins/Defaults.py
@@ -1,5 +1,6 @@
 """This generator provides rule-based entry mappings."""
 
+import Bcfg2.Options
 import Bcfg2.Server.Plugin
 import Bcfg2.Server.Plugins.Rules
 
@@ -9,7 +10,10 @@ class Defaults(Bcfg2.Server.Plugins.Rules.Rules,
     """Set default attributes on bound entries"""
     __author__ = 'bcfg-dev@mcs.anl.gov'
 
-    options = Bcfg2.Server.Plugin.PrioDir.options
+    options = Bcfg2.Server.Plugin.PrioDir.options + [
+        Bcfg2.Options.BooleanOption(
+            cf=("defaults", "replace_name"), dest="defaults_replace_name",
+            help="Replace %{name} in attributes with name of target entry")]
 
     # Rules is a Generator that happens to implement all of the
     # functionality we want, so we overload it, but Defaults should
@@ -41,3 +45,9 @@ class Defaults(Bcfg2.Server.Plugins.Rules.Rules,
     def _regex_enabled(self):
         """ Defaults depends on regex matching, so force it enabled """
         return True
+
+    @property
+    def _replace_name_enabled(self):
+        """ Return True if the replace_name feature is enabled,
+        False otherwise """
+        return Bcfg2.Options.setup.defaults_replace_name
diff --git a/src/lib/Bcfg2/Server/Plugins/Rules.py b/src/lib/Bcfg2/Server/Plugins/Rules.py
index a3f682ed6..cf659251c 100644
--- a/src/lib/Bcfg2/Server/Plugins/Rules.py
+++ b/src/lib/Bcfg2/Server/Plugins/Rules.py
@@ -1,10 +1,17 @@
 """This generator provides rule-based entry mappings."""
 
+import copy
 import re
+import string
 import Bcfg2.Options
 import Bcfg2.Server.Plugin
 
 
+class NameTemplate(string.Template):
+    """Simple subclass of string.Template with a custom delimiter."""
+    delimiter = '%'
+
+
 class Rules(Bcfg2.Server.Plugin.PrioDir):
     """This is a generator that handles service assignments."""
     __author__ = 'bcfg-dev@mcs.anl.gov'
@@ -12,7 +19,10 @@ class Rules(Bcfg2.Server.Plugin.PrioDir):
     options = Bcfg2.Server.Plugin.PrioDir.options + [
         Bcfg2.Options.BooleanOption(
             cf=("rules", "regex"), dest="rules_regex",
-            help="Allow regular expressions in Rules")]
+            help="Allow regular expressions in Rules"),
+        Bcfg2.Options.BooleanOption(
+            cf=("rules", "replace_name"), dest="rules_replace_name",
+            help="Replace %{name} in attributes with name of target entry")]
 
     def __init__(self, core):
         Bcfg2.Server.Plugin.PrioDir.__init__(self, core)
@@ -46,7 +56,22 @@ class Rules(Bcfg2.Server.Plugin.PrioDir):
                 return True
         return False
 
+    def _apply(self, entry, data):
+        if self._replace_name_enabled:
+            data = copy.deepcopy(data)
+            for key, val in list(data.attrib.items()):
+                data.attrib[key] = NameTemplate(val).safe_substitute(
+                    name=entry.get('name'))
+
+        Bcfg2.Server.Plugin.PrioDir._apply(self, entry, data)
+
     @property
     def _regex_enabled(self):
         """ Return True if rules regexes are enabled, False otherwise """
         return Bcfg2.Options.setup.rules_regex
+
+    @property
+    def _replace_name_enabled(self):
+        """ Return True if the replace_name feature is enabled,
+        False otherwise """
+        return Bcfg2.Options.setup.rules_replace_name
diff --git a/testsuite/Testsrc/Testlib/TestServer/TestPlugins/TestDefaults.py b/testsuite/Testsrc/Testlib/TestServer/TestPlugins/TestDefaults.py
index 9b4a6af88..3c660099e 100644
--- a/testsuite/Testsrc/Testlib/TestServer/TestPlugins/TestDefaults.py
+++ b/testsuite/Testsrc/Testlib/TestServer/TestPlugins/TestDefaults.py
@@ -22,6 +22,10 @@ from Testinterfaces import TestGoalValidator
 class TestDefaults(TestRules, TestGoalValidator):
     test_obj = Defaults
 
+    def setUp(self):
+        TestRules.setUp(self)
+        set_setup_default("defaults_replace_name", True)
+
     def get_obj(self, *args, **kwargs):
         return TestRules.get_obj(self, *args, **kwargs)
 
@@ -91,3 +95,8 @@ class TestDefaults(TestRules, TestGoalValidator):
 
     def test_regex(self):
         self._do_test('regex')
+
+    def test_replace_name(self):
+        Bcfg2.Options.setup.defaults_replace_name = True
+        self._do_test('replace_name')
+        Bcfg2.Options.setup.defaults_replace_name = False
diff --git a/testsuite/Testsrc/Testlib/TestServer/TestPlugins/TestRules.py b/testsuite/Testsrc/Testlib/TestServer/TestPlugins/TestRules.py
index 45f3671e8..88b334edf 100644
--- a/testsuite/Testsrc/Testlib/TestServer/TestPlugins/TestRules.py
+++ b/testsuite/Testsrc/Testlib/TestServer/TestPlugins/TestRules.py
@@ -32,6 +32,7 @@ class TestRules(TestPrioDir):
         group=lxml.etree.Element("SEPort", name="6789/tcp"),
         children=lxml.etree.Element("Path", name="/etc/child-entries"),
         regex=lxml.etree.Element("Package", name="regex"),
+        replace_name=lxml.etree.Element("POSIXUser", name="regex"),
         slash=lxml.etree.Element("Path", name="/etc/trailing/slash"),
         no_slash=lxml.etree.Element("Path", name="/etc/no/trailing/slash/"))
 
@@ -53,6 +54,8 @@ class TestRules(TestPrioDir):
                                     group="root", mode="0775"),
         regex=lxml.etree.Element("Package", name="regex", type="yum",
                                  version="any"),
+        replace_name=lxml.etree.Element("POSIXUser", name="regex",
+                                        home="/foobar%{bar}/regex"),
         slash=lxml.etree.Element("Path", name="/etc/trailing/slash",
                                  type="directory", owner="root", group="root",
                                  mode="0600"),
@@ -70,6 +73,8 @@ class TestRules(TestPrioDir):
 
     in_file = copy.deepcopy(concrete)
     in_file['regex'].set("name", ".*")
+    in_file['replace_name'].set("home", "/foobar%{bar}/%{name}")
+    in_file['replace_name'].set("name", ".*")
     in_file['slash'].set("name", "/etc/trailing/slash/")
     in_file['no_slash'].set("name", "/etc/no/trailing/slash")
 
@@ -91,6 +96,7 @@ class TestRules(TestPrioDir):
     rules3 = lxml.etree.Element("Rules", priority="10")
     rules3.append(in_file['duplicate'])
     rules3.append(in_file['regex'])
+    rules3.append(in_file['replace_name'])
     rules3.append(in_file['slash'])
 
     rules = {"rules1.xml": rules1, "rules2.xml": rules2, "rules3.xml": rules3}
@@ -99,6 +105,7 @@ class TestRules(TestPrioDir):
         TestPrioDir.setUp(self)
         set_setup_default("lax_decryption", True)
         set_setup_default("rules_regex", False)
+        set_setup_default("rules_replace_name", False)
 
     def get_child(self, name):
         """ Turn one of the XML documents in `rules` into a child
@@ -169,6 +176,17 @@ class TestRules(TestPrioDir):
         self._do_test('regex')
         Bcfg2.Options.setup.rules_regex = False
 
+    def test_replace_name(self):
+        """ Test that Rules handles replaces name in attribues with regular expressions """
+        Bcfg2.Options.setup.rules_regex = False
+        Bcfg2.Options.setup.rules_replace_name = False
+        self._do_test_failure('replace_name', handles=False)
+        Bcfg2.Options.setup.rules_regex = True
+        Bcfg2.Options.setup.rules_replace_name = True
+        self._do_test('replace_name')
+        Bcfg2.Options.setup.rules_regex = False
+        Bcfg2.Options.setup.rules_replace_name = False
+
     def test_slash(self):
         """ Test that Rules handles trailing slashes on Path entries """
         self._do_test('slash')