More adjustments/cleanups for the system configuration

helper objects.

1. Add in a parser for the /etc/hostname file that can be shared
2. Adjust the sysconfig configobj parser to not always quote
   fields that it does not need to quote + add in tests around
   this to ensure that we don't go nuts with quoting again.

1 files changed, 85 insertions, 0 deletions

diff --git a/cloudinit/distros/parsers/sys_conf.py b/cloudinit/distros/parsers/sys_conf.py
new file mode 100644
index 00000000..3d8802b8
--- /dev/null
+++ b/cloudinit/distros/parsers/sys_conf.py
@@ -0,0 +1,85 @@
+# vi: ts=4 expandtab
+#
+#    Copyright (C) 2012 Yahoo! Inc.
+#
+#    Author: Joshua Harlow <harlowja@yahoo-inc.com>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License version 3, as
+#    published by the Free Software Foundation.
+#
+#    This program 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, see <http://www.gnu.org/licenses/>.
+
+from StringIO import StringIO
+
+import re
+
+# This library is used to parse/write
+# out the various sysconfig files edited
+#
+# It has to be slightly modified though
+# to ensure that all values are quoted/unquoted correctly
+# since these configs are usually sourced into
+# bash scripts...
+import configobj
+
+
+class SysConf(configobj.ConfigObj):
+    def __init__(self, contents):
+        configobj.ConfigObj.__init__(self, contents,
+                                     interpolation=False,
+                                     write_empty_values=True)
+
+    def __str__(self):
+        contents = self.write()
+        out_contents = StringIO()
+        if isinstance(contents, (list, tuple)):
+            out_contents.write("\n".join(contents))
+        else:
+            out_contents.write(str(contents))
+        return out_contents.getvalue()
+
+    def _quote(self, value, multiline=False):
+        if not isinstance(value, (str, basestring)):
+            raise ValueError('Value "%s" is not a string' % (value))
+        if len(value) == 0:
+            return ''
+        if re.search(r"[\n\r]", value):
+            raise ValueError('Value "%s" cannot be safely quoted.' % (value))
+        quot = "%s"
+        if '#' in value:
+            quot = self._get_single_quote(value)
+        elif value[0] in ['"', "'"] and value[-1] in ['"', "'"]:
+            # Already quoted, leave it be
+            pass
+        elif "'" in value and '"' in value:
+            quot = self._get_triple_quote(value)
+        else:
+            # Quote whitespace if it isn't the start+end of a shell command
+            white_space_ok = False
+            if value.strip().startswith("$(") and value.strip().endswith(")"):
+                white_space_ok = True
+            if re.search(r"[\t ]", value) and not white_space_ok:
+                quot = self._get_single_quote(value)
+        return quot % (value)
+
+    def _write_line(self, indent_string, entry, this_entry, comment):
+        # Ensure it is formatted fine for
+        # how these sysconfig scripts are used
+        if this_entry.startswith("'") or this_entry.startswith('"'):
+            val = this_entry
+        val = self._decode_element(self._quote(this_entry))
+        key = self._decode_element(self._quote(entry))
+        cmnt = self._decode_element(comment)
+        return '%s%s%s%s%s' % (indent_string,
+                               key,
+                               self._a_to_u('='),
+                               val,
+                               cmnt)
+