diff options
| -rw-r--r-- | cloudinit/helpers.py | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/cloudinit/helpers.py b/cloudinit/helpers.py index 21d203db..45633e0f 100644 --- a/cloudinit/helpers.py +++ b/cloudinit/helpers.py @@ -23,8 +23,11 @@ from time import time import contextlib +import io import os +from ConfigParser import (NoSectionError, NoOptionError, RawConfigParser) + from cloudinit.settings import (PER_INSTANCE, PER_ALWAYS, PER_ONCE) from cloudinit import log as logging @@ -298,3 +301,63 @@ class Paths(object): return None else: return ipath + + +# This config parser will not throw when sections don't exist +# and you are setting values on those sections which is useful +# when writing to new options that may not have corresponding +# sections. Also it can default other values when doing gets +# so that if those sections/options do not exist you will +# get a default instead of an error. Another useful case where +# you can avoid catching exceptions that you typically don't +# care about... + +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 |