[elk]logstash grok原理

logstash语法

http://www.ttlsa.com/elk/elk-logstash-configuration-syntax/
https://www.elastic.co/guide/en/logstash/current/event-dependent-configuration.html

logstash grok原理

参考:
https://www.kancloud.cn/hanxt/elk/155901
https://www.elastic.co/guide/en/logstash/current/plugins-filters-grok.html

正则表达式参考:
https://github.com/kkos/oniguruma/blob/master/doc/RE

grok的意思: (用感觉感知,而非动脑思考)to understand sth completely using your feelings rather than considering the facts

• 这个目录下有各种定义好的正则字段

/usr/local/logstash/vendor/bundle/jruby/1.9/gems/logstash-patterns-core-4.1.2/patterns

或者直接访问这个:
https://github.com/elastic/logstash/blob/v1.4.2/patterns/grok-patterns


$  ls /usr/local/logstash/vendor/bundle/jruby/1.9/gems/logstash-patterns-core-4.1.2/patterns/
aws     bind  exim       grok-patterns  httpd  junos         maven        mcollective-patterns  nagios      rails  ruby
bacula  bro   firewalls  haproxy        java   linux-syslog  mcollective  mongodb               postgresql  redis  squid

如apache日志解析: logstash过滤解析apache日志

filter {
    grok {
        match => { "message" => "%{COMBINEDAPACHELOG}"}
    }
}

logstash内置的pattern的定义(嵌套调用)

再举个例子
%{IP:client} 这里意思是: 用IP正则去匹配日志内容,匹配到的内容存储在key client里.

input {
  file {
    path => "/var/log/http.log"
  }
}
filter {
  grok {
    match => { "message" => "%{IP:client} %{WORD:method} %{URIPATHPARAM:request} %{NUMBER:bytes} %{NUMBER:duration}" }
  }
}
output {
    stdout { codec => rubydebug }
}

grok的remove_field

参考:
https://www.elastic.co/guide/en/logstash/current/plugins-filters-grok.html
https://doc.yonyoucloud.com/doc/logstash-best-practice-cn/filter/grok.html

我们只需要request_time字段,默认仅match会读取message某字段赋给新字段,这样就造成了数据重复,为了解决这个问题,干掉message字段

input {stdin{}}
filter {
    grok {
        match => {
            "message" => "s+(?<request_time>d+(?:.d+)?)s+"
        }
    }
}
output {stdout{ codec => rubydebug }}

begin 123.456 end
{
        "@version" => "1",
            "host" => "ip-70.32.1.32.hosted.by.gigenet.com",
      "@timestamp" => 2017-11-29T03:47:15.377Z,
    "request_time" => "123.456",
         "message" => "begin 123.456 end"
}

input {stdin{}}
filter {
    grok {
        match => {
            "message" => "s+(?<request_time>d+(?:.d+)?)s+"
        }
        remove_field => ["message"]
    }
}
output {stdout{ codec => rubydebug }}




begin 123.456 end
{
        "@version" => "1",
            "host" => "ip-70.32.1.32.hosted.by.gigenet.com",
      "@timestamp" => 2017-11-29T03:51:01.135Z,
    "request_time" => "123.456"
}

自定义pattern

参考: https://www.elastic.co/guide/en/logstash/current/plugins-filters-grok.html
可以写文件里,也可以直接指定,如上一个例子.

$ cat /var/sample.log
Jan  1 06:25:43 mailserver14 postfix/cleanup[21403]: BEF25A72965: message-id=<20130101142543.5828399CCAF@mailserver14.example.com>

$ cat ./patterns/postfix:
POSTFIX_QUEUEID [0-9A-F]{10,11}

input {
  file {
    path => "/var/sample.log"
  }
}
filter {
  grok {
    patterns_dir => ["./patterns"]
    match => { "message" => "%{SYSLOGBASE} %{POSTFIX_QUEUEID:queue_id}: %{GREEDYDATA:syslog_message}" }
  }
}
output {
    stdout { codec => rubydebug }
}

grok解析apache日志,并修改date格式

参考:http://blog.51cto.com/irow10/1828077 这里格式有问题,我修复了.

input {
  stdin {}
}
filter {
    grok {
      match => { "message" => "%{IPORHOST:addre} %{USER:ident} %{USER:auth} [%{HTTPDATE:timestamp}] "%{WORD:http_method} %{NOTSPACE:request} HTTP/%{NUMBER:httpversion}" %{NUMBER:status} (?:%{NUMBER:bytes}|-) "(?:%{URI:http_referer}|-)" "%{GREEDYDATA:User_Agent}"" }
      remove_field => ["message"]
    }
    date {
      match => [ "timestamp", "dd/MMM/YYYY:HH:mm:ss Z" ]
    }
}

output {
    stdout { codec => rubydebug }
}

192.168.10.97 - - [19/Jul/2016:16:28:52 +0800] "GET / HTTP/1.1" 200 23 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36"
{
        "request" => "/",
           "auth" => "-",
          "ident" => "-",
     "User_Agent" => "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36",
          "addre" => "192.168.10.97",
     "@timestamp" => 2016-07-19T08:28:52.000Z,
    "http_method" => "GET",
          "bytes" => "23",
       "@version" => "1",
           "host" => "no190.pp100.net",
    "httpversion" => "1.1",
      "timestamp" => "19/Jul/2016:16:28:52 +0800",
         "status" => "200"
}

grok在线检测
参考: http://grokdebug.herokuapp.com/

192.168.10.97 - - [19/Jul/2016:16:28:52 +0800] "GET / HTTP/1.1" 200 23 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36"

%{IPORHOST:addre} %{USER:ident} %{USER:auth} [%{HTTPDATE:timestamp}] "%{WORD:http_method} %{NOTSPACE:request} HTTP/%{NUMBER:httpversion}" %{NUMBER:status} (?:%{NUMBER:bytes}|-) "(?:%{URI:http_referer}|-)" "%{GREEDYDATA:User_Agent}"

logstash mutate插件-给整个条目添加个字段

参考: https://www.elastic.co/guide/en/logstash/current/event-dependent-configuration.html

input { stdin { } }

filter {
  mutate { add_field => { "show" => "This data will be in the output" } }
}

output {
  if [@metadata][test] == "Hello" {
    stdout { codec => rubydebug }
  }
}

sdf
{
      "@version" => "1",
          "host" => "ip-70.32.1.32.hosted.by.gigenet.com",
          "show" => "This data will be in the output",
    "@timestamp" => 2017-11-29T09:23:44.160Z,
       "message" => "sdf"
}

logstash input添加字段-add_field

参考: http://www.21yunwei.com/archives/5296

input {
  file {
        path => "/logs/nginx/access.log"
        type => "nginx"
        start_position => "beginning"
        add_field => { "key"=>"value"}
        codec => "json"
}
 
}
output {
stdout{
        codec => rubydebug{ }
}
}

logstash 5大插件--待了解

参考:
http://blog.51cto.com/irow10/1828077
https://segmentfault.com/a/1190000011721483
https://www.elastic.co/guide/en/logstash/current/plugins-filters-kv.html

date插件可以对日期格式定义
mutate插件可以增删字段,可以改写字段格式
kv插件可...

使用上面的日志作为示例，使用 mutate 插件的 lowercase 配置选项，我们可以将“log-level”字段转换为小写：

filter { 
    grok {...}
    mutate {   lowercase => [ "log-level" ]  }
}

kv filter 来指示 Logstash 如何处理它
kv插件可以拆解

filter {  
kv {
source => "metadata"
trim => """
include_keys => [ "level","service","customerid",”queryid” ]
target => "kv"
    }
}