This provides a nice little utility class that avoids the python config parser throwing when options + values are being added to unknown sections since it handles the

creation and checking that those sections exist before the option is added. Also it adds a little helper that can turn that config into a string.

1 files changed, 72 insertions, 0 deletions

diff --git a/cloudinit/cfg.py b/cloudinit/cfg.py
new file mode 100644
index 00000000..dd8f7baf
--- /dev/null
+++ b/cloudinit/cfg.py
@@ -0,0 +1,72 @@
+# 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/>.
+
+import io
+
+from ConfigParser import (NoSectionError, NoOptionError, RawConfigParser)
+
+
+class DefaultingConfigParser(RawConfigParser):
+    DEF_INT = 0
+    DEF_FLOAT = 0.0
+    DEF_BOOLEAN = False
+    DEF_BASE = None
+
+    def get(self, section, option):
+        value = self.DEF_BASE
+        try:
+            value = RawConfigParser.get(self, section, option)
+        except NoSectionError:
+            pass
+        except NoOptionError:
+            pass
+        return value
+
+    def set(self, section, option, value):
+        if not self.has_section(section) and section.lower() != 'default':
+            self.add_section(section)
+        RawConfigParser.set(self, section, option, value)
+
+    def remove_option(self, section, option):
+        if self.has_option(section, option):
+            RawConfigParser.remove_option(self, section, option)
+
+    def getboolean(self, section, option):
+        if not self.has_option(section, option):
+            return self.DEF_BOOLEAN
+        return RawConfigParser.getboolean(self, section, option)
+
+    def getfloat(self, section, option):
+        if not self.has_option(section, option):
+            return self.DEF_FLOAT
+        return RawConfigParser.getfloat(self, section, option)
+
+    def getint(self, section, option):
+        if not self.has_option(section, option):
+            return self.DEF_INT
+        return RawConfigParser.getint(self, section, option)
+
+    def stringify(self, header=None):
+        contents = ''
+        with io.BytesIO() as outputstream:
+            self.write(outputstream)
+            outputstream.flush()
+            contents = outputstream.getvalue()
+            if header:
+                contents = "\n".join([header, contents])
+        return contents