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.

4 files changed, 177 insertions, 81 deletions

diff --git a/cloudinit/distros/parsers/hostname.py b/cloudinit/distros/parsers/hostname.py
new file mode 100644
index 00000000..7e19f017
--- /dev/null
+++ b/cloudinit/distros/parsers/hostname.py
@@ -0,0 +1,90 @@
+# 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
+
+from cloudinit.distros.parsers import chop_comment
+
+
+# Parser that knows how to work with /etc/hostname format
+class HostnameConf(object):
+    def __init__(self, text):
+        self._text = text
+        self._contents = None
+
+    def parse(self):
+        if self._contents is None:
+            self._contents = self._parse(self._text)
+
+    def __str__(self):
+        self.parse()
+        contents = StringIO()
+        for (line_type, components) in self._contents:
+            if line_type == 'blank':
+                contents.write("%s\n" % (components[0]))
+            elif line_type == 'all_comment':
+                contents.write("%s\n" % (components[0]))
+            elif line_type == 'hostname':
+                (hostname, tail) = components
+                contents.write("%s%s\n" % (hostname, tail))
+        # Ensure trailing newline
+        contents = contents.getvalue()
+        if not contents.endswith("\n"):
+            contents += "\n"
+        return contents
+
+    @property
+    def hostname(self):
+        self.parse()
+        for (line_type, components) in self._contents:
+            if line_type == 'hostname':
+                return components[0]
+        return None
+
+    def set_hostname(self, your_hostname):
+        your_hostname = your_hostname.strip()
+        if not your_hostname:
+            return
+        self.parse()
+        replaced = False
+        for (line_type, components) in self._contents:
+            if line_type == 'hostname':
+                components[0] = str(your_hostname)
+                replaced = True
+        if not replaced:
+            self._contents.append(('hostname', [str(your_hostname), '']))
+
+    def _parse(self, contents):
+        entries = []
+        hostnames_found = set()
+        for line in contents.splitlines():
+            if not len(line.strip()):
+                entries.append(('blank', [line]))
+                continue
+            (head, tail) = chop_comment(line.strip(), '#')
+            if not len(head):
+                entries.append(('all_comment', [line]))
+                continue
+            entries.append(('hostname', [head, tail]))
+            hostnames_found.add(head)
+        if len(hostnames_found) > 1:
+            raise IOError("Multiple hostnames (%s) found!"
+                           % (hostnames_found))
+        return entries
+    
+    
diff --git a/cloudinit/distros/parsers/hosts.py b/cloudinit/distros/parsers/hosts.py
index 5374ab0b..958a7c31 100644
--- a/cloudinit/distros/parsers/hosts.py
+++ b/cloudinit/distros/parsers/hosts.py
@@ -23,6 +23,7 @@ from cloudinit.distros.parsers import chop_comment
 
 # See: man hosts
 # or http://unixhelp.ed.ac.uk/CGI/man-cgi?hosts
+# or http://tinyurl.com/6lmox3
 class HostsConf(object):
     def __init__(self, text):
         self._text = text
@@ -80,7 +81,7 @@ class HostsConf(object):
         contents = StringIO()
         for (line_type, components) in self._contents:
             if line_type == 'blank':
-                contents.write("%s\n")
+                contents.write("%s\n" % (components[0]))
             elif line_type == 'all_comment':
                 contents.write("%s\n" % (components[0]))
             elif line_type == 'option':
diff --git a/cloudinit/distros/parsers/quoting_conf.py b/cloudinit/distros/parsers/quoting_conf.py
deleted file mode 100644
index 953ccfe9..00000000
--- a/cloudinit/distros/parsers/quoting_conf.py
+++ /dev/null
@@ -1,80 +0,0 @@
-# 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/>.
-
-# 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
-# since these configs are usually sourced into
-# bash scripts...
-from configobj import ConfigObj
-
-# See: http://tiny.cc/oezbgw
-D_QUOTE_CHARS = {
-    "\"": "\\\"",
-    "(": "\\(",
-    ")": "\\)",
-    "$": '\$',
-    '`': '\`',
-}
-
-# This class helps adjust the configobj
-# writing to ensure that when writing a k/v
-# on a line, that they are properly quoted
-# and have no spaces between the '=' sign.
-# - This is mainly due to the fact that
-# the sysconfig scripts are often sourced
-# directly into bash/shell scripts so ensure
-# that it works for those types of use cases.
-class QuotingConfigObj(ConfigObj):
-    def __init__(self, lines):
-        ConfigObj.__init__(self, lines,
-                           interpolation=False,
-                           write_empty_values=True)
-
-    def _quote_posix(self, text):
-        if not text:
-            return ''
-        for (k, v) in D_QUOTE_CHARS.iteritems():
-            text = text.replace(k, v)
-        return '"%s"' % (text)
-
-    def _quote_special(self, text):
-        if text.lower() in ['yes', 'no', 'true', 'false']:
-            return text
-        else:
-            return self._quote_posix(text)
-
-    def _write_line(self, indent_string, entry, this_entry, comment):
-        # Ensure it is formatted fine for
-        # how these sysconfig scripts are used
-        val = self._decode_element(self._quote(this_entry))
-        # Single quoted strings should
-        # always work.
-        if not val.startswith("'"):
-            # Perform any special quoting
-            val = self._quote_special(val)
-        key = self._decode_element(self._quote(entry, multiline=False))
-        cmnt = self._decode_element(comment)
-        return '%s%s%s%s%s' % (indent_string,
-                               key,
-                               "=",
-                               val,
-                               cmnt)
-
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)
+