logstash常见的几种过滤器

logstash简介

logstash项目是2009年8月2日诞生，作者是著名运维工程师乔丹西塞，后被Elasticsearch公司收购。
logstash 是一个具有实时渠道的数据收集引擎。使用JRuby 语言编写。
logstash提供很多功能强大的滤网以满足各种应用场景

logstash过滤器插件filter详解及实例

1.1、grok正则捕获

grok是一个十分强大的logstash filter插件，他可以通过正则解析任意文本，将非结构化日志数据弄成结构化和方便查询的结构。他是目前logstash 中解析非结构化日志数据最好的方式
grok的语法规则是 

%{语法：语义}

“语法”指的是匹配的模式。例如使用NUMBER模式可以匹配出数字，IP模式则会匹配出127.0.0.1这样的IP地址。


172.16.213.132 [07/Feb/2018:16:24:19 +0800] "GET /HTTP/1.1" 403 5039

**1过滤IP **


input {
        stdin {
filter{
        grok{
                match => {"message" => "%{IPV4:ip}"}
output {
                stdout {

启动logstash可以得到


172.16.213.132 [07/Feb/2018:16:24:19 +0800]"GET /HTTP/1.1" 403 5039　#手动输入此行信息
       "message" => "172.16.213.132 [07/Feb/2018:16:24:19 +0800]\"GET /HTTP/1.1\" 403 5039",
            "ip" => "172.16.213.132",
      "@version" => "1",
          "host" => "ip-172-31-22-29.ec2.internal",
    "@timestamp" => 2019-01-22T09:48:15.354Z

结果中有IP

2）举个例子来讲解过滤时间戳


filter{
        grok{
                match => {"message" => "%{IPV4:ip}\ \[%{HTTPDATE:timestamp}\]"}

172.16.213.132 [07/Feb/2018:16:24:19 +0800]"GET /HTTP/1.1" 403 5039　手动输入此行信息
      "@version" => "1",
     "timestamp" => "07/Feb/2018:16:24:19 +0800",
    "@timestamp" => 2019-01-22T10:16:14.205Z,
       "message" => "172.16.213.132 [07/Feb/2018:16:24:19 +0800]\"GET /HTTP/1.1\" 403 5039",
            "ip" => "172.16.213.132",
          "host" => "ip-172-31-22-29.ec2.internal"

3）过滤出报文头信息


filter{
        grok{
                match => {"message" => "\ %{QS:referrer}\ "}

172.16.213.132 - - [07/Feb/2018:16:24:19 +0800] "GET /HTTP/1.1" 403 5039
    "@timestamp" => 2019-01-22T10:47:37.127Z,
       "message" => "172.16.213.132 - - [07/Feb/2018:16:24:19 +0800] \"GET /HTTP/1.1\" 403 5039",
      "@version" => "1",
          "host" => "ip-172-31-22-29.ec2.internal",
      "referrer" => "\"GET /HTTP/1.1\""

1.2、date插件


在上面我们有个例子是讲解timestamp字段，表示取出日志中的时间。但是在显示的时候除了显示你指定的timestamp外，还有一行是@timestamp信息，这两个时间是不一样的，@timestamp表示系统当前时间。两个时间并不是一回事，在ELK的日志处理系统中，@timestamp字段会被elasticsearch用到，用来标注日志的生产时间，如此一来，日志生成时间就会发生混乱，要解决这个问题，需要用到另一个插件，即date插件，这个时间插件用来转换日志记录中的时间字符串，变成Logstash::Timestamp对象，然后转存到@timestamp字段里面


filter{
        grok{
                match => {"message" => "\ -\ -\ \[%{HTTPDATE:timestamp}\]"}
        date{
                match => ["timestamp","dd/MMM/yyyy:HH:mm:ss Z"]

注意：时区偏移量需要用一个字母Z来转换。还有这里的“dd/MMM/yyyy”，你发现中间是三个大写的M，没错，这里确实是三个大写的M，我尝试只写两个M的话，转换失败


172.16.213.132 - - [07/Feb/2018:16:24:19 +0800] "GET /HTTP/1.1" 403 5039  #手动输入此行信息
          "host" => "ip-172-31-22-29.ec2.internal",
     "timestamp" => "07/Feb/2018:16:24:19 +0800",
    "@timestamp" => 2018-02-07T08:24:19.000Z,
       "message" => "172.16.213.132 - - [07/Feb/2018:16:24:19 +0800] \"GET /HTTP/1.1\" 403 5039",
      "@version" => "1"

1.3、数据修改mutate插件


mutate插件是logstash另一个非常重要的插件，它提供了丰富的基础类型数据处理能力，包括重命名、删除、替换、修改日志事件中的字段。我们这里举几个常用的mutate插件：字段类型转换功能covert、正则表达式替换字段功能gsub、分隔符分隔字符串为数值功能split、重命名字段功能rename、删除字段功能remove_field

1)   remove_field的用法

remove_field的用法也是很常见的，他的作用就是去重，在前面的例子中你也看到了，不管是我们要输出什么样子的信息，都是有两份数据，即message里面是一份，HTTPDATE或者IP里面也有一份，这样子就造成了重复，过滤的目的就是筛选出有用的信息，重复的不要，因此我们看看如何去重呢？

我们还是以输出IP为例：


filter{
        grok{
                match => {"message" => "%{IP:ip_address}"}
                remove_field => ["message"]

172.16.213.132 - - [07/Feb/2018:16:24:19 +0800] "GET /HTTP/1.1" 403 5039　#手动输入此行内容并按enter键
    "ip_address" => "172.16.213.132",
          "host" => "ip-172-31-22-29.ec2.internal",
      "@version" => "1",
    "@timestamp" => 2019-01-22T12:16:58.918Z

这时候你会发现没有之前显示的那个message的那一行信息了。因为我们使用remove_field把他移除了，这样的好处显而易见，我们只需要日志中特定的信息而已。


  • 字段类型转换convert
    • 

    filter{
        grok{
                match => {"message" => "%{IPV4:ip}"}
                remove_field => ["message"]
        mutate{
                convert => ["ip","string"]

    172.16.213.132 - - [07/Feb/2018:16:24:9 +0800] "GET /HTTP/1.1" 403 5039
    "@timestamp" => 2019-01-23T04:13:55.261Z,
            "ip" => "172.16.213.132",
          "host" => "ip-172-31-22-29.ec2.internal",
      "@version" => "1"

    3）正则表达式替换匹配字段
    
gsub可以通过正则表达式替换字段中匹配到的值，但是这本身只对字符串字段有效。
    

    filter{
        grok{
                match => {"message" => "%{QS:referrer}"}
                remove_field => ["message"]
        mutate{
                gsub => ["referrer","/","-"]
     "host" => "ip-172-31-22-29.ec2.internal",
     "@timestamp" => 2019-01-23T05:51:30.786Z,
     "@version" => "1",
     "referrer" => "\"GET -HTTP-1.1\""

    4）分隔符分隔字符串为数组
    
split可以通过指定的分隔符分隔字段中的字符串为数组
    

    filter{
        mutate{
                split => ["message","-"]
                add_field => ["A is lower case :","%{[message][0]}"]

    a-b-c-d-e-f-g　　　　　　　　　　　　#手动输入此行内容，并按下enter键。
        [0] "a",
        [1] "b",
        [2] "c",
        [3] "d",
        [4] "e",
        [5] "f",
        [6] "g"
     "host" => "ip-172-31-22-29.ec2.internal",
     "@version" => "1",
     "@timestamp" => 2019-01-23T06:07:18.062Z

    5）重命名字段
    
rename可以实现重命名某个字段的功能。
    

    filter{
        grok{
                match => {"message" => "%{IPV4:ip}"}
                remove_field => ["message"]
        mutate{
                convert => {
                        "ip" => "string"
                rename => {
                        "ip"=>"IP"

    rename字段使用大括号{}括起来，其实我们也可以使用中括号达到同样的目的
    

    mutate{
                convert => {
                        "ip" => "string"
                rename => ["ip","IP"]

    172.16.213.132 - - [07/Feb/2018:16:24:9 +0800] "GET /HTTP/1.1" 403 5039　　　　　　#手动输入此内容
      "@version" => "1",
    "@timestamp" => 2019-01-23T06:20:21.423Z,
          "host" => "ip-172-31-22-29.ec2.internal",
            "IP" => "172.16.213.132"

    6）添加字段add_field
    

    添加字段多用于split分隔中，主要是对split分隔后的字段中指定格式输出。
    

    filter {
  mutate {
    split => ["message", "|"]
      add_field => {
        "timestamp" => "%{[message][0]}"

    添加字段后，该字段会与@timestamp一样同等格式显示出来。
    

    1.4、geoip地址查询归类
    

    geoip是常见的免费的IP地址归类查询库，geoip可以根据IP地址提供对应的地域信息，包括国别，省市，经纬度等等，此插件对于可视化地图和区域统计非常有用。
    

    filter{
        grok {
                match => {
                        "message" => "%{IP:ip}"
                remove_field => ["message"]
        geoip {
                source => "ip"

    114.55.68.111 - - [07/Feb/2018:16:24:9 +0800] "GET /HTTP/1.1" 403 5039　　　　　　#手动输入此行信息
            "ip" => "114.55.68.111",
         "geoip" => {
             "city_name" => "Hangzhou",
           "region_code" => "33",
              "location" => {
            "lat" => 30.2936,
            "lon" => 120.1614
             "longitude" => 120.1614,
              "latitude" => 30.2936,
         "country_code2" => "CN",
              "timezone" => "Asia/Shanghai",
                    "ip" => "114.55.68.111",
         "country_code3" => "CN",
        "continent_code" => "AS",
          "country_name" => "China",
           "region_name" => "Zhejiang"
          "host" => "ip-172-31-22-29.ec2.internal",
      "@version" => "1",
    "@timestamp" => 2019-01-23T06:47:51.200Z

    但是上面的内容并不是每个都是我们想要的，因此我们可以选择性的输出。
    

    继续修改内容如下：
    

    filter{
        grok {
                match => ["message","%{IP:ip}"]
                remove_field => ["message"]
        geoip {
                source => ["ip"]
                target => ["geoip"]
                fields => ["city_name","region_name","country_name","ip"]

    filter{
        grok {
                match => ["message","%{IP:ip}"]
                remove_field => ["message"]
        geoip {
                source => ["ip"]
                target => ["geoip"]
                fields => ["city_name","region_name","country_name","ip"]

    1.5、filter插件综合应用。
    

    我们的业务例子如下所示：
    

    112.195.209.90 - - [20/Feb/2018:12:12:14 +0800] "GET / HTTP/1.1" 200 190 "-" "Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Mobile Safari/537.36" "-"

    日志中的双引号、单引号、中括号等不能被正则解析的都要加上转义符号，详情可见这里：https://www.cnblogs.com/ysk123/p/9858387.html
    

    现在我们修改配置文件进行匹配
    

    filter{
        grok {
                match => ["message","%{IPORHOST:client_ip}\ -\ -\ \[%{HTTPDATE:timestamp}\]\ %{QS:referrer}\ %{NUMBER:status}\ %{NUMBER:bytes}\ \"-\"\ \"%{DATA:browser_info}\ %{GREEDYDATA:extra_info}\"\ \"-\""]
        geoip {
                source => ["client_ip"]
                target => ["geoip"]
                fields => ["city_name","region_name","country_name","ip"]
        date {
                match => ["timestamp","dd/MMM/yyyy:HH:mm:ss Z"]
        mutate {
                remove_field => ["message","timestamp"]

    然后启动一下看看效果：
    
        "referrer" => "\"GET / HTTP/1.1\"",
           "bytes" => "190",
       "client_ip" => "112.195.209.90",
      "@timestamp" => 2018-02-20T04:12:14.000Z,
    "browser_info" => "Mozilla/5.0",
      "extra_info" => "(Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Mobile Safari/537.36",
          "status" => "200",
            "host" => "ip-172-31-22-29.ec2.internal",
        "@version" => "1",
           "geoip" => {
           "city_name" => "Chengdu",
         "region_name" => "Sichuan",
        "country_name" => "China",
                  "ip" => "112.195.209.90"