saltstack源码-启动２－parsers.py选项初始化１

class MasterOptionParser(OptionParser, ConfigDirMixIn, MergeConfigMixIn,
                         LogLevelMixIn, RunUserMixin, DaemonMixIn,
                         PidfileMixin):#这些差不多全是ｓａｌｔ初始化的类,有的minion也会调用

    __metaclass__ = OptionParserMeta #指定他的元类

    description = 'The Salt master, used to control the Salt minions.'

    # ConfigDirMixIn config filename attribute
    _config_filename_ = 'master'＃默认配置文件名
    # LogLevelMixIn attributes
    _default_logging_logfile_ = os.path.join(syspaths.LOGS_DIR, 'master') #这里是得到他的日志文件路径/var/log/salt/master

    def setup_config(self):
        return config.master_config(self.get_config_file_path())

接下来就是查找他的元类
python类在初始化的时候，经历了两个阶段，第一个阶段是分配空间__new__()，第二个阶段是初始化值__init__()。当类被创建时，python会首先寻找__metaclass__是否存在，
如果存在则调用__metaclass__。如果此类没定义__metaclass__就去看父类，父类没有就去模块里找（全局变量__metaclass__），
模块里再没有就把__metaclass__ = type作为类的metaclass。
mcs代表调用__new__函数的class，name代表对象的__name__值，也就是名称，bases代表对象的父类元组，attrs代表类的属性字典.

class MixInMeta(type):
    # This attribute here won't actually do anything. But, if you need to
    # specify an order or a dependency within the mix-ins, please define the
    # attribute on your own MixIn
    _mixin_prio_ = 0

    def __new__(mcs, name, bases, attrs):
        instance = super(MixInMeta, mcs).__new__(mcs, name, bases, attrs)
        if not hasattr(instance, '_mixin_setup'):
            raise RuntimeError(
                'Don\'t subclass {0} in {1} if you\'re not going to use it '
                'as a salt parser mix-in.'.format(mcs.__name__, name)
            )
        return instance

class OptionParserMeta(MixInMeta):
    def __new__(mcs, name, bases, attrs):
        instance = super(OptionParserMeta, mcs).__new__(mcs,
                                                        name,
                                                        bases,
                                                        attrs)
        #上面调用父类的MinInMeta.__new__方法
    if not hasattr(instance, '_mixin_setup_funcs'):
            instance._mixin_setup_funcs = []
        if not hasattr(instance, '_mixin_process_funcs'):
            instance._mixin_process_funcs = []
        if not hasattr(instance, '_mixin_after_parsed_funcs'):
            instance._mixin_after_parsed_funcs = []
        #这条语句分别创建了3个空列表

        for base in _sorted(bases + (instance,)):
        #这里是把基类和子类进行排序
            func = getattr(base, '_mixin_setup', None)#得到所有类_mixin_setup属性方法,没有就赋值为None
            if func is not None and func not in instance._mixin_setup_funcs:
                instance._mixin_setup_funcs.append(func)
                #for循环过后得到的列表 _mixin_setup_funcs[ConfigDirMixIn._mixin_setup,
                #                                          LogLevelMixIn._mixin_setup,
                #                                         RunUserMixin._mixin_setup,
                #                                         DaemonMixIn_mixin_setup,
                #                                         PidfileMixin._mixin_setup,
                #                                         ]
                #这些类方法是初始化salt的选项命令

            func = getattr(base, '_mixin_after_parsed', None)##得到所有类_mixin_after_parsed属性方法,没有就赋值为None
            if func is not None and func not in \
                    instance._mixin_after_parsed_funcs:
                instance._mixin_after_parsed_funcs.append(func)
            #这个列表如果是启动的话在这是空列表，不过会在OptionParser的parse_args方法里面实现添加

            # Mark process_<opt> functions with the base priority for sorting
            for func in dir(base):
                if not func.startswith('process_'):
                    continue

                func = getattr(base, func)
                if getattr(func, '_mixin_prio_', None) is not None:
                    # Function already has the attribute set, don't override it
                    continue

                func.__func__._mixin_prio_ = getattr(
                    base, '_mixin_prio_', 1000
                )
            #这个for循环把所有没_mixin_prio属性的基类 设置属性值1000

        return instance #返回实例 

接下来就是调用OptionParser的__init__()方法来初始化了
接着调用的OptionParser的parse_args方法

    def parse_args(self, args=None, values=None):
        options, args = optparse.OptionParser.parse_args(self, args, values)
＃上面这句options的值是{'daemon': False, 'log_level': None, 'versions_report': None, 'user': None, 'log_file': None, 'config_dir': '/etc/salt', 'pidfile': '/var/run/salt.pid', 'log_level_logfile': None}
＃惭愧　到现在都还没找到这些值是怎么来的，找了好久都没找到，后来干脆就不找了，现往下看完再说，别吊死在这
        if options.versions_report:
            self.print_versions_report()

        self.options, self.args = options, args

        # Let's get some proper sys.stderr logging as soon as possible!!!
        # This logging handler will be removed once the proper console or
        # logfile logging is setup.
        log.setup_temp_logger(
            getattr(self.options, 'log_level', 'error')
        )

        # Gather and run the process_<option> functions in the proper order
        process_option_funcs = []
        for option_key in options.__dict__.keys():
            process_option_func = getattr(
                self, 'process_{0}'.format(option_key), None
            )
            if process_option_func is not None:
                process_option_funcs.append(process_option_func)
＃下面分别执行这３个方法process_config_dir　　process_log_level　　　　process_log_file

        for process_option_func in _sorted(process_option_funcs):
            try:
                process_option_func()
            except Exception as err:
                logging.getLogger(__name__).exception(err)
                self.error(
                    'Error while processing {0}: {1}'.format(
                        process_option_func, traceback.format_exc(err)
                    )
                )
＃首先看一下ConfigDirMixIn．process_config_dir 方法
    def process_config_dir(self):
        if not os.path.isdir(self.options.config_dir):
            # No logging is configured yet
            sys.stderr.write(
                'WARNING: {0!r} directory does not exist.\n'.format(
                    self.options.config_dir
                )
            )

        # Make sure we have an absolute path
        self.options.config_dir = os.path.abspath(self.options.config_dir)

        if hasattr(self, 'setup_config'):
            try:
                self.config = self.setup_config()
                #这里调用子类的MasterOptionParser.setup_config 方法，其方法原型如下：
                ＃def setup_config(self):
                 ＃   return config.master_config(self.get_config_file_path())
            except (IOError, OSError) as exc:
                self.error(
                    'Failed to load configuration: {0}'.format(exc)
                )

那个get_config_file_path()返回配置文件的绝对路径然后作为参数传至config.py里面的master_config()方法
草！又调到config.py了，４个编辑器完全不够我用的．．．妈的继续往下去看