add uncomment function

devstack/dsconf.py

@@ -64,7 +64,7 @@ class IniFile(object):
                     writer.write("[%s]\n" % section)
                     writer.write("%s = %s\n" % (name, value))
 
-    def _at_existing_key(self, section, name, func):
+    def _at_existing_key(self, section, name, func, match="%s\s*\="):
         temp = tempfile.NamedTemporaryFile(mode='r')
         shutil.copyfile(self.fname, temp.name)
         current_section = ""
@@ -75,7 +75,7 @@ class IniFile(object):
                     if m:
                         current_section = m.group(1)
                     if current_section == section:
-                        if re.match("%s\s*\=" % name, line):
+                        if re.match(match % name, line):
                             # run function with writer and found line
                             func(writer, line)
                         else:
@@ -98,6 +98,12 @@ class IniFile(object):
 
         self._at_existing_key(section, name, _do_comment)
 
+    def uncomment(self, section, name):
+        def _do_uncomment(writer, line):
+            writer.write(re.sub("^#\s*", "", line))
+
+        self._at_existing_key(section, name, _do_uncomment, match="#\s*%s\s*\=")
+
     def set(self, section, name, value):
         def _do_set(writer, line):
             writer.write("%s = %s\n" % (name, value))

devstack/tests/test_ini_uncomment.py

@@ -0,0 +1,113 @@
+# Copyright 2017 IBM
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+# Implementation of ini add / remove for devstack. We don't use the
+# python ConfigFile parser because that ends up rewriting the entire
+# file and doesn't ensure comments remain.
+
+import fixtures
+import testtools
+
+from devstack import dsconf
+
+
+BASIC = """[default]
+a = b
+c = d
+# f = 1
+[second]
+e = f
+g = h
+# h = 2
+[new]
+s = t
+# x = 3
+"""
+
+RESULT1 = """[default]
+a = b
+c = d
+f = 1
+[second]
+e = f
+g = h
+# h = 2
+[new]
+s = t
+# x = 3
+"""
+
+RESULT2 = """[default]
+a = b
+c = d
+# f = 1
+[second]
+e = f
+g = h
+h = 2
+[new]
+s = t
+# x = 3
+"""
+
+RESULT3 = """[default]
+a = b
+c = d
+# f = 1
+[second]
+e = f
+g = h
+# h = 2
+[new]
+s = t
+x = 3
+"""
+
+
+class TestIniUncomment(testtools.TestCase):
+
+    def setUp(self):
+        super(TestIniUncomment, self).setUp()
+        self._path = self.useFixture(fixtures.TempDir()).path
+        self._path += "/test.ini"
+        with open(self._path, "w") as f:
+            f.write(BASIC)
+
+    def test_uncomment_ini_default(self):
+        conf = dsconf.IniFile(self._path)
+        conf.uncomment("default", "f")
+        with open(self._path) as f:
+            content = f.read()
+            self.assertEqual(content, RESULT1)
+
+    def test_uncomment_ini_second(self):
+        conf = dsconf.IniFile(self._path)
+        conf.uncomment("second", "h")
+        with open(self._path) as f:
+            content = f.read()
+            self.assertEqual(content, RESULT2)
+
+    def test_uncomment_ini_new(self):
+        conf = dsconf.IniFile(self._path)
+        conf.uncomment("new", "x")
+        with open(self._path) as f:
+            content = f.read()
+            self.assertEqual(content, RESULT3)
+
+    def test_uncomment_ini_none(self):
+        conf = dsconf.IniFile(self._path)
+        conf.uncomment("default", "s")
+        with open(self._path) as f:
+            content = f.read()
+            self.assertEqual(content, BASIC)