日志服务：通过Syslog投递日志到SIEM

推荐使用日志服务消费组构建程序来进行实时消费，然后通过Syslog over TCP/TLS来发送日志给SIEM。

如下代码展示主程序控制逻辑。

def main():
    option, settings = get_monitor_option()

    logger.info("*** start to consume data...")
    worker = ConsumerWorker(SyncData, option, args=(settings,) )
    worker.start(join=True)

if __name__ == '__main__':
    main()

如下代码展示如何从日志服务获取数据投递到SIEM Syslog服务器。请仔细阅读代码中相关注释并根据需求调整格式。

from syslogclient import SyslogClientRFC5424 as SyslogClient

class SyncData(ConsumerProcessorBase):
    """
    消费者从日志服务消费数据并发送给Syslog server。
    """
    def __init__(self, splunk_setting):
      """初始化并验证Syslog server连通性。"""
        super(SyncData, self).__init__()   # remember to call base's init

        assert target_setting, ValueError("You need to configure settings of remote target")
        assert isinstance(target_setting, dict), ValueError("The settings should be dict to include necessary address and confidentials.")

        self.option = target_setting
        self.protocol = self.option['protocol']
        self.timeout = int(self.option.get('timeout', 120))
        self.sep = self.option.get('sep', "||")
        self.host = self.option["host"]
        self.port = int(self.option.get('port', 514))
        self.cert_path=self.option.get('cert_path', None)

        # try connection
        with SyslogClient(self.host, self.port, proto=self.protocol, timeout=self.timeout, cert_path=self.cert_path) as client:
            pass

    def process(self, log_groups, check_point_tracker):
        logs = PullLogResponse.loggroups_to_flattern_list(log_groups, time_as_str=True, decode_bytes=True)
        logger.info("Get data from shard {0}, log count: {1}".format(self.shard_id, len(logs)))
        try:
            with SyslogClient(self.host, self.port, proto=self.protocol, timeout=self.timeout, cert_path=self.cert_path) as client:
                for log in logs:
                    # Put your sync code here to send to remote.
                    # the format of log is just a dict with example as below (Note, all strings are unicode):
                    #    Python2: {"__time__": "12312312", "__topic__": "topic", u"field1": u"value1", u"field2": u"value2"}
                    #    Python3: {"__time__": "12312312", "__topic__": "topic", "field1": "value1", "field2": "value2"}
                    # suppose we only care about audit log
                    timestamp = datetime.fromtimestamp(int(log[u'__time__']))
                    del log['__time__']

                    io = six.StringIO()
                    first = True
          # 可以根据需要修改格式化内容，这里使用Key=Value传输，并使用默认的双竖线（||）进行分割。
                    for k, v in six.iteritems(log):
                        io.write("{0}{1}={2}".format(self.sep, k, v))

                    data = io.getvalue()

          # 可以根据需要修改facility或者severity。
                    client.log(data, facility=self.option.get("facility", None), severity=self.option.get("severity", None), timestamp=timestamp, program=self.option.get("tag", None), hostname=self.option.get("hostname", None))

        except Exception as err:
            logger.debug("Failed to connect to remote syslog server ({0}). Exception: {1}".format(self.option, err))

            # 需要添加一些错误处理的代码，例如重试或者通知等。
            raise err

        logger.info("Complete send data to remote")

        self.save_checkpoint(check_point_tracker)

例如程序命名为sync_data.py，启动程序示例如下所示。

export SLS_ENDPOINT=<Endpoint of your region>
export SLS_AK_ID=<YOUR AK ID>
export SLS_AK_KEY=<YOUR AK KEY>
export SLS_PROJECT=<SLS Project Name>
export SLS_LOGSTORE=<SLS Logstore Name>
export SLS_CG=<消费组名，可以简单命名为"syc_data">

python3 sync_data.py

基于消费组的程序，可以直接启动多次程序以实现并发效果。

nohup python3 sync_data.py &
nohup python3 sync_data.py &
nohup python3 sync_data.py &
...