Use a regex in installutils.get_directive instead of line splitting

This will allow for whitespace around the separator and changes the
default space separator into white space (space + tabs) to be more
generic and work better on Ubuntu which uses tabs in its Apache
configuration.

https://pagure.io/freeipa/issue/7490

Signed-off-by: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>

ipaserver/install/installutils.py

@@ -605,13 +605,20 @@ def get_directive(filename, directive, separator=' '):
 
     :returns: The (unquoted) value if the directive was found, None otherwise
     """
+    # Special case: consider space as "white space" so tabs are allowed
+    if separator == ' ':
+        separator = '[ \t]+'
+
     fd = open(filename, "r")
     for line in fd:
         if line.lstrip().startswith(directive):
             line = line.strip()
 
-            (directive, sep, value) = line.partition(separator)
-            if not sep or not value:
+            match = re.match(r'{}\s*{}\s*(.*)'.format(directive, separator),
+                             line)
+            if match:
+                value = match.group(1)
+            else:
                 raise ValueError("Malformed directive: {}".format(line))
 
             result = unquote_directive_value(value.strip(), '"')

ipatests/test_ipaserver/test_install/test_installutils.py

@@ -98,6 +98,30 @@ class test_set_directive(object):
             os.remove(filename)
 
 
+class test_get_directive(object):
+    def test_get_directive(self, tmpdir):
+        configfile = tmpdir.join('config')
+        configfile.write(''.join(EXAMPLE_CONFIG))
+
+        assert '1' == installutils.get_directive(str(configfile),
+                                                 'foo',
+                                                 separator='=')
+        assert '2' == installutils.get_directive(str(configfile),
+                                                 'foobar',
+                                                 separator='=')
+
+
+class test_get_directive_whitespace(object):
+    def test_get_directive(self, tmpdir):
+        configfile = tmpdir.join('config')
+        configfile.write(''.join(WHITESPACE_CONFIG))
+
+        assert '1' == installutils.get_directive(str(configfile),
+                                                 'foo')
+        assert '2' == installutils.get_directive(str(configfile),
+                                                 'foobar')
+
+
 def test_directivesetter(tempdir):
     filename = os.path.join(tempdir, 'example.conf')
     with open(filename, 'w') as f: