DEFAULT_MASTER_OPTS = {    ‘interface‘: ‘0.0.0.0‘,    ‘publish_port‘: ‘4505‘,    ‘pub_hwm‘: 1000,    ‘auth_mode‘: 1,    ‘user‘: ‘root‘,    ‘worker_threads‘: 5,    ‘sock_dir‘: os.path.join(salt.syspaths.SOCK_DIR, ‘master‘),    ‘ret_port‘: ‘4506‘,    ‘timeout‘: 5,    ‘keep_jobs‘: 24,    ‘root_dir‘: salt.syspaths.ROOT_DIR,    ‘pki_dir‘: os.path.join(salt.syspaths.CONFIG_DIR, ‘pki‘, ‘master‘),    ‘cachedir‘: os.path.join(salt.syspaths.CACHE_DIR, ‘master‘),    ‘file_roots‘: {        ‘base‘: [salt.syspaths.BASE_FILE_ROOTS_DIR],    },    ‘master_roots‘: {        ‘base‘: [salt.syspaths.BASE_MASTER_ROOTS_DIR],    },    ‘pillar_roots‘: {        ‘base‘: [salt.syspaths.BASE_PILLAR_ROOTS_DIR],    },    ‘gitfs_remotes‘: [],    ‘gitfs_root‘: ‘‘,    ‘gitfs_base‘: ‘master‘,    ‘hgfs_remotes‘: [],    ‘hgfs_root‘: ‘‘,    ‘hgfs_base‘: ‘default‘,    ‘hgfs_branch_method‘: ‘branches‘,    ‘svnfs_remotes‘: [],    ‘svnfs_root‘: ‘‘,    ‘ext_pillar‘: [],    ‘pillar_version‘: 2,    ‘pillar_opts‘: True,    ‘peer‘: {},    ‘syndic_master‘: ‘‘,    ‘runner_dirs‘: [],    ‘outputter_dirs‘: [],    ‘client_acl‘: {},    ‘client_acl_blacklist‘: {},    ‘external_auth‘: {},    ‘token_expire‘: 43200,    ‘file_recv‘: False,    ‘file_buffer_size‘: 1048576,    ‘file_ignore_regex‘: None,    ‘file_ignore_glob‘: None,    ‘fileserver_backend‘: [‘roots‘],    ‘fileserver_followsymlinks‘: True,    ‘fileserver_ignoresymlinks‘: False,    ‘fileserver_limit_traversal‘: False,    ‘max_open_files‘: 100000,    ‘hash_type‘: ‘md5‘,    ‘conf_file‘: os.path.join(salt.syspaths.CONFIG_DIR, ‘master‘),    ‘open_mode‘: False,    ‘auto_accept‘: False,    ‘renderer‘: ‘yaml_jinja‘,    ‘failhard‘: False,    ‘state_top‘: ‘top.sls‘,    ‘master_tops‘: {},    ‘external_nodes‘: ‘‘,    ‘order_masters‘: False,    ‘job_cache‘: True,    ‘ext_job_cache‘: ‘‘,    ‘master_ext_job_cache‘: ‘‘,    ‘minion_data_cache‘: True,    ‘enforce_mine_cache‘: False,    ‘ipv6‘: False,    ‘log_file‘: os.path.join(salt.syspaths.LOGS_DIR, ‘master‘),    ‘log_level‘: None,    ‘log_level_logfile‘: None,    ‘log_datefmt‘: _DFLT_LOG_DATEFMT,    ‘log_datefmt_logfile‘: _DFLT_LOG_DATEFMT_LOGFILE,    ‘log_fmt_console‘: _DFLT_LOG_FMT_CONSOLE,    ‘log_fmt_logfile‘: _DFLT_LOG_FMT_LOGFILE,    ‘log_granular_levels‘: {},    ‘pidfile‘: os.path.join(salt.syspaths.PIDFILE_DIR, ‘salt-master.pid‘),    ‘publish_session‘: 86400,    ‘cluster_masters‘: [],    ‘cluster_mode‘: ‘paranoid‘,    ‘range_server‘: ‘range:80‘,    ‘reactor‘: [],    ‘serial‘: ‘msgpack‘,    ‘state_verbose‘: True,    ‘state_output‘: ‘full‘,    ‘state_auto_order‘: True,    ‘state_events‘: False,    ‘search‘: ‘‘,    ‘search_index_interval‘: 3600,    ‘loop_interval‘: 60,    ‘nodegroups‘: {},    ‘cython_enable‘: False,    ‘enable_gpu_grains‘: False,    # XXX: Remove ‘key_logfile‘ support in 2014.1.0    ‘key_logfile‘: os.path.join(salt.syspaths.LOGS_DIR, ‘key‘),    ‘verify_env‘: True,    ‘permissive_pki_access‘: False,    ‘default_include‘: ‘master.d/*.conf‘,    ‘win_repo‘: os.path.join(salt.syspaths.BASE_FILE_ROOTS_DIR, ‘win‘, ‘repo‘),    ‘win_repo_mastercachefile‘: os.path.join(salt.syspaths.BASE_FILE_ROOTS_DIR,                                             ‘win‘, ‘repo‘, ‘winrepo.p‘),    ‘win_gitrepos‘: [‘https://github.com/saltstack/salt-winrepo.git‘],    ‘syndic_wait‘: 1,    ‘jinja_lstrip_blocks‘: False,    ‘jinja_trim_blocks‘: False,    ‘sign_pub_messages‘: False,    ‘keysize‘: 4096,    ‘salt_transport‘: ‘zeromq‘,    ‘gather_job_timeout‘: 2,    ‘enumerate_proxy_minions‘: False,    ‘ssh_passwd‘: ‘‘,    ‘ssh_port‘: ‘22‘,    ‘ssh_sudo‘: False,    ‘ssh_timeout‘: 60,    ‘ssh_user‘: ‘root‘,}

def master_config(path, env_var=‘SALT_MASTER_CONFIG‘, defaults=None):    ‘‘‘    Reads in the master configuration file and sets up default options    ‘‘‘    if defaults is None:        defaults = DEFAULT_MASTER_OPTS ＃默认配置选项     if not os.environ.get(env_var, None):＃这里取的是反值        # No valid setting was given using the configuration variable.        # Lets see is SALT_CONFIG_DIR is of any use        salt_config_dir = os.environ.get(‘SALT_CONFIG_DIR‘, None)        ＃启动初始化的时候是继承系统的环境变量，所以SALT_CONFIG_DIR变量是不存在的，　        if salt_config_dir:            env_config_file_path = os.path.join(salt_config_dir, ‘master‘)            if salt_config_dir and os.path.isfile(env_config_file_path):                # We can get a configuration file using SALT_CONFIG_DIR, let‘s                # update the environment with this information                os.environ[env_var] = env_config_file_path     overrides = load_config(path, env_var, DEFAULT_MASTER_OPTS[‘conf_file‘])    ＃load_config(path=‘/etc/salt/master‘,env_var=‘SALT_MASTER_CONFIG‘,default_path=/etc/salt/master‘‘)    ＃返回值和属性是配置文件的不是默认的    default_include = overrides.get(‘default_include‘,                                    defaults[‘default_include‘])    include = overrides.get(‘include‘, [])     overrides.update(include_config(default_include, path, verbose=False))    overrides.update(include_config(include, path, verbose=True))    #这２个update目前还没添加任何的配置属性和值    opts = apply_master_config(overrides, defaults) #这个把配置文件的选项和值覆盖掉默认的，顺便添加几个选项    _validate_opts(opts)　＃这个主要是验证，配置是否正确的类型    # If ‘nodegroups:‘ is uncommented in the master config file, and there are    # no nodegroups defined, opts[‘nodegroups‘] will be None. Fix this by    # reverting this value to the default, as if ‘nodegroups:‘ was commented    # out or not present.    if opts.get(‘nodegroups‘) is None:        opts[‘nodegroups‘] = DEFAULT_MASTER_OPTS.get(‘nodegroups‘, {})    return opts　　

def load_config(path, env_var, default_path=None):    ‘‘‘    Returns configuration dict from parsing either the file described by    ``path`` or the environment variable described by ``env_var`` as YAML.    ‘‘‘    if path is None:        # When the passed path is None, we just want the configuration        # defaults, not actually loading the whole configuration.        return {}     if default_path is None: #        # This is most likely not being used from salt, ie, could be salt-cloud        # or salt-api which have not yet migrated to the new default_path        # argument. Let‘s issue a warning message that the environ vars won‘t        # work.        import inspect        previous_frame = inspect.getframeinfo(inspect.currentframe().f_back)        log.warning(            ‘The function \‘{0}()\‘ defined in {1!r} is not yet using the ‘            ‘new \‘default_path\‘ argument to `salt.config.load_config()`. ‘            ‘As such, the {2!r} environment variable will be ignored‘.format(                previous_frame.function, previous_frame.filename, env_var            )        )        # In this case, maintain old behaviour        default_path = DEFAULT_MASTER_OPTS[‘conf_file‘]     # Default to the environment variable path, if it exists    env_path = os.environ.get(env_var, path) #这里把path的值赋予env_path    if not env_path or not os.path.isfile(env_path):        env_path = path    # If non-default path from `-c`, use that over the env variable    if path != default_path:        env_path = path     path = env_path     # If the configuration file is missing, attempt to copy the template,    # after removing the first header line.    if not os.path.isfile(path):        template = ‘{0}.template‘.format(path)        if os.path.isfile(template):            log.debug(‘Writing {0} based on {1}‘.format(path, template))            with salt.utils.fopen(path, ‘w‘) as out:                with salt.utils.fopen(template, ‘r‘) as ifile:                    ifile.readline()  # skip first line                    out.write(ifile.read())     if salt.utils.validate.path.is_readable(path):#这里调用的方法是判断是否为文件和可读的属性        opts = _read_conf_file(path)　　＃获得配置文件的属性和值        opts[‘conf_file‘] = path　　　　　＃这里是设置默认配置文件路径        return opts　　　　　　　　　　　＃返回配置文件的属性和值     log.debug(‘Missing configuration file: {0}‘.format(path))    return {}

def _read_conf_file(path):    log.debug(‘Reading configuration from {0}‘.format(path))    with salt.utils.fopen(path, ‘r‘) as conf_file:        try:            conf_opts = yaml.safe_load(conf_file.read()) or {}　＃读取配置文件的属性和值        except yaml.YAMLError as err:            log.error(                ‘Error parsing configuration file: {0} - {1}‘.format(path, err)            )            conf_opts = {}        # only interpret documents as a valid conf, not things like strings,        # which might have been caused by invalid yaml syntax        if not isinstance(conf_opts, dict):            log.error(                ‘Error parsing configuration file: {0} - conf should be a ‘                ‘document, not {1}.‘.format(path, type(conf_opts))            )            conf_opts = {}        # allow using numeric ids: convert int to string        if ‘id‘ in conf_opts:　　＃这条判断语句目前暂时只有minion会用的，master配置文件暂时还没用到ｉｄ选项            conf_opts[‘id‘] = str(conf_opts[‘id‘])        for key, value in conf_opts.copy().iteritems():            if isinstance(value, unicode):　　＃判断属性值是否为unicode类型                # We do not want unicode settings                conf_opts[key] = value.encode(‘utf-8‘)        return conf_opts　　＃返回配置文件的属性和值的字典

def apply_master_config(overrides=None, defaults=None):    ‘‘‘    Returns master configurations dict.    ‘‘‘    if defaults is None:        defaults = DEFAULT_MASTER_OPTS     opts = defaults.copy()    if overrides:        opts.update(overrides)　　＃使用配置文件选项覆字典盖掉默认的选项     if len(opts[‘sock_dir‘]) > len(opts[‘cachedir‘]) + 10:        opts[‘sock_dir‘] = os.path.join(opts[‘cachedir‘], ‘.salt-unix‘)     opts[‘aes‘] = salt.crypt.Crypticle.generate_key_string()      #这里是添加一个aes键作为配置选项，它的默认值默认是随机返回一个56位byte值的base64解码表示    ＃一看就知道是加密用的    opts[‘extension_modules‘] = (        opts.get(‘extension_modules‘) or        os.path.join(opts[‘cachedir‘], ‘extmods‘)    )    #添加一个extension_modules键　值是/var/cache/salt/extmods    opts[‘token_dir‘] = os.path.join(opts[‘cachedir‘], ‘tokens‘)    #添加一个token_dir键　值是/var/cache/salt/tokens     # Prepend root_dir to other paths    prepend_root_dirs = [        ‘pki_dir‘, ‘cachedir‘, ‘pidfile‘, ‘sock_dir‘, ‘extension_modules‘,        ‘autosign_file‘, ‘autoreject_file‘, ‘token_dir‘    ]     # These can be set to syslog, so, not actual paths on the system    for config_key in (‘log_file‘, ‘key_logfile‘):        log_setting = opts.get(config_key, ‘‘)        if log_setting is None:            continue         if urlparse.urlparse(log_setting).scheme == ‘‘:            prepend_root_dirs.append(config_key)    #向列表里面再添加２个元素　‘log_file‘,‘key_logfile‘      prepend_root_dir(opts, prepend_root_dirs)    #这个函数只要是起规范路径的作用..    # Enabling open mode requires that the value be set to True, and    # nothing else!    opts[‘open_mode‘] = opts[‘open_mode‘] is True    opts[‘auto_accept‘] = opts[‘auto_accept‘] is True    opts[‘file_roots‘] = _validate_file_roots(opts)     if opts[‘file_ignore_regex‘]:        # If file_ignore_regex was given, make sure it‘s wrapped in a list.        # Only keep valid regex entries for improved performance later on.        if isinstance(opts[‘file_ignore_regex‘], str):            ignore_regex = [opts[‘file_ignore_regex‘]]        elif isinstance(opts[‘file_ignore_regex‘], list):            ignore_regex = opts[‘file_ignore_regex‘]         opts[‘file_ignore_regex‘] = []        for regex in ignore_regex:            try:                # Can‘t store compiled regex itself in opts (breaks                # serialization)                re.compile(regex)                opts[‘file_ignore_regex‘].append(regex)            except Exception:                log.warning(                    ‘Unable to parse file_ignore_regex. Skipping: {0}‘.format(                        regex                    )                )     if opts[‘file_ignore_glob‘]:        # If file_ignore_glob was given, make sure it‘s wrapped in a list.        if isinstance(opts[‘file_ignore_glob‘], str):            opts[‘file_ignore_glob‘] = [opts[‘file_ignore_glob‘]]     # Let‘s make sure `worker_threads` does not drop bellow 3 which has proven    # to make `salt.modules.publish` not work under the test-suite.    if opts[‘worker_threads‘] < 3 and opts.get(‘peer‘, None):        log.warning(            ‘The \‘worker_threads\‘ setting on {0!r} cannot be lower than 3. ‘            ‘Resetting it to the default value of 3.‘.format(                opts[‘conf_file‘]            )        )        opts[‘worker_threads‘] = 3    return opts