Update discovery config for all instances.

    :param opts:
    :return:

def _update_discovery_config(opts):
    '''
    Update discovery config for all instances.

    :param opts:
    :return:
    '''
    if opts.get('discovery') not in (None, False):
        if opts['discovery'] is True:
            opts['discovery'] = {}
        discovery_config = {'attempts': 3, 'pause': 5, 'port': 4520, 'match': 'any', 'mapping': {}, 'multimaster': False}
        for key in opts['discovery']:
            if key not in discovery_config:
                raise salt.exceptions.SaltConfigurationError('Unknown discovery option: {0}'.format(key))
        if opts.get('__role') != 'minion':
            for key in ['attempts', 'pause', 'match']:
                del discovery_config[key]
        opts['discovery'] = salt.utils.dictupdate.update(discovery_config, opts['discovery'], True, True)