AWS ELB access log 的logstash Grok终极匹配pattern 和 grok替代思路

grok {
  match => { "message" => "%{TIMESTAMP_ISO8601:timestamp} %{NOTSPACE:elb_name} %{IP:elb_client_ip}:%{INT:elb_client_port:int} (?:%{IP:elb_backend_ip}:%{NUMBER:elb_backend_port:int}|-) (?:%{NUMBER:request_processing_time:float}|-1) (?:%{NUMBER:backend_processing_time:float}|-1) (?:%{NUMBER:requestresponse_processing_time:float}|-1) %{INT:elb_status_code:int} %{INT:backend_status_code:int} %{INT:elb_received_bytes:int} %{INT:elb_sent_bytes:int} \"%{GREEDYDATA:elb_request}\" \"%{GREEDYDATA:userAgent}\" (?:%{NOTSPACE:elb_sslcipher}|-) (?:%{NOTSPACE:elb_sslprotocol}|-)"}

  }

官方给的没有考虑到-1和-这种特殊情况（为什么有这种特殊，请见aws官方 说明)。

测试样本如下，

2017-03-01T02:20:13.897023Z cf 88.99.90.240:56230 - -1 -1 -1 504 0 0 0 "GET HTTP/1.1" "Mozilla/4.0 (compatible; cron-job.org; )" ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2

2017-03-01T02:24:06.194449Z cf 167.89.125.231:61926 10.10.81.5:80 0.000049 0.000447 0.000026 400 400 522 15 "POST HTTP/1.1" "SendGrid Event API" ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2

2017-03-01T02:14:34.610166Z cf 54.87.226.214:32068 - -1 -1 -1 504 0 0 0 "GET HTTP/1.1" "-" - -

此外ruby code和event结合在某些情况下可以结合使用替代grok,grok比较耗费资源。

https://www.elastic.co/blog/do-you-grok-grok


多说一个经验，

> name = ['client','servername','url']


name.zip(("chrome web ").split())
=> [["client", "chrome"], ["servername", "web"], ["url", ""]]


> Hash[name.zip(("chrome web ").split())]
=> {"client"=>"chrome", "servername"=>"web", "url"=>""}


结合https://www.elastic.co/guide/en/logstash/current/event-api.html 
可以用ruby这个filter来get 某个filed然后分割，再set回去，适用于grok的pattern非常难的情况。示例如下


filter {
  
 ruby {


     init =>"key = ['x','y'......]"
    code =>"
     new_event = Hash[key.zip(event.get('YOUR_FIELD').split(' '))]
     event.set(new_event)
     " 
 }


}