日志分析平台ELK之日志收集器filebeat

　　前面我們了解了elk集群中的logstash的用法，使用logstash處理日志挺好的，但是有一個缺陷，就是太慢了；當然logstash慢的原因是它依賴jruby虛擬機，jruby虛擬機就是用java語言開發的ruby虛擬機，本身java程序運行在jvm上就已經很慢了，而logstash還要運行在用java語言開發的ruby虛擬機上，就相當於虛擬機上跑一個虛擬機，可想而知；如果我們只需要收集和處理日志，在agent端如果運行logstash，顯得格外的消耗資源；為了解決這種問題，elastic開發了一款更加輕量級的日志收集器beats；而filebeat只是其中的一種，它是基於收集本地日志文件中的內容，然后輸出到某個地方；中間不會對日志做過多的處理；有點類似rsyslog，只做日志轉發；如果我們需要對日志做處理，我們可以把filebeat的輸出源配置成logstash，讓logstash運行在一個獨立的服務器上，專門做日志處理；

　　filebeat收集日志過程

　　提示：以上是filebeat收集日志，然后把日志轉發給logstash進行分析，然后logstash把filebeat發送過來的日志，做切詞，分析，處理以后，然后在把日志發送給elasticsearch存儲；

　　提示：如果后端的filebeat一旦增多，logstash的壓力會非常大，為了解決這樣的問題，我們可在中間加redis是做臨時緩存；然后logstash就到redis里讀日志；然后再把讀到的日志存儲到elasticsearch中；當然filebeat也是可以直接將日志數據發送給elasticsearch進行存儲；

　　filebeat安裝

　　下載同elasticsearch版本的filebeat rpm包

[root@node03 ~]# wget https://artifacts.elastic.co/downloads/beats/filebeat/filebeat-6.8.12-x86_64.rpm
--2020-10-04 14:03:03--  https://artifacts.elastic.co/downloads/beats/filebeat/filebeat-6.8.12-x86_64.rpm
Resolving artifacts.elastic.co (artifacts.elastic.co)... 151.101.230.222, 2a04:4e42:36::734
Connecting to artifacts.elastic.co (artifacts.elastic.co)|151.101.230.222|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 11904164 (11M) [application/octet-stream]
Saving to: ‘filebeat-6.8.12-x86_64.rpm’

100%[================================================================================>] 11,904,164  9.76KB/s   in 16m 35s

2020-10-04 14:19:41 (11.7 KB/s) - ‘filebeat-6.8.12-x86_64.rpm’ saved [11904164/11904164]

[root@node03 ~]# ll
total 184540
-rw-r--r-- 1 root root  11904164 Aug 18 19:35 filebeat-6.8.12-x86_64.rpm
-rw-r--r-- 1 root root 177059640 Aug 18 19:41 logstash-6.8.12.rpm
[root@node03 ~]# 

　　安裝filebeat-6.8.12.rpm包

[root@node03 ~]# yum install ./filebeat-6.8.12-x86_64.rpm -y
Loaded plugins: fastestmirror
Examining ./filebeat-6.8.12-x86_64.rpm: filebeat-6.8.12-1.x86_64
Marking ./filebeat-6.8.12-x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package filebeat.x86_64 0:6.8.12-1 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

==========================================================================================================================
 Package                  Arch                   Version                    Repository                               Size
==========================================================================================================================
Installing:
 filebeat                 x86_64                 6.8.12-1                   /filebeat-6.8.12-x86_64                  38 M

Transaction Summary
==========================================================================================================================
Install  1 Package

Total size: 38 M
Installed size: 38 M
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : filebeat-6.8.12-1.x86_64                                                                               1/1 
  Verifying  : filebeat-6.8.12-1.x86_64                                                                               1/1 

Installed:
  filebeat.x86_64 0:6.8.12-1                                                                                              

Complete!
[root@node03 ~]# 

　　示例：配置filebeat收集httpd的日志，然后將收集的日志輸出到logstash

　　提示：以上配置表示開啟filebeat插件收集/var/log/httpd/access_log中的日志；

　　提示：以上配置表示把filebeat收集的日志發送給node03：5044；

　　配置node03的logstash輸入數據監聽5044端口

　　提示：以上配置表示啟動logstash中的beats插件作為數據輸入，並監聽5044端口；然后logstash將處理后端日志數據輸出到標准輸出；

　　啟動filebeat和logstash

　　提示：可以看到logstash啟動時，它監聽5044端口；

　　用其他主機模擬互聯網用戶訪問node03的httpd提供的頁面

[root@node01 ~]# curl -H "X-Forwarded-For:$[$RANDOM%223+1].$[RANDOM%255].$[RANDOM%255].$[RANDOM%255]" http://node03/test$[$RANDOM%20+1].html
page 18
[root@node01 ~]# 

　　在node03的logstash的標准輸出上，看看是否收集到httpd的訪問日志？

/usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/awesome_print-1.7.0/lib/awesome_print/formatters/base_formatter.rb:31: warning: constant ::Fixnum is deprecated
{
            "host" => {
                   "os" => {
            "platform" => "centos",
             "version" => "7 (Core)",
              "family" => "redhat",
                "name" => "CentOS Linux",
            "codename" => "Core"
        },
        "containerized" => false,
         "architecture" => "x86_64",
                 "name" => "node03.test.org",
                   "id" => "002f3e572e3e4886ac9e98db8584b467"
    },
      "prospector" => {
        "type" => "log"
    },
            "auth" => "-",
        "clientip" => "25.99.168.124",
           "agent" => "\"curl/7.29.0\"",
            "tags" => [
        [0] "beats_input_codec_plain_applied"
    ],
      "@timestamp" => 2020-10-04T06:49:34.000Z,
        "@version" => "1",
           "bytes" => "8",
          "offset" => 0,
            "verb" => "GET",
        "referrer" => "\"-\"",
          "source" => "/var/log/httpd/access_log",
             "log" => {
        "file" => {
            "path" => "/var/log/httpd/access_log"
        }
    },
    "clientipInfo" => {
        "continent_code" => "EU",
             "longitude" => -0.1224,
         "country_code2" => "GB",
                    "ip" => "25.99.168.124",
          "country_name" => "United Kingdom",
         "country_code3" => "GB",
              "location" => {
            "lat" => 51.4964,
            "lon" => -0.1224
        },
              "timezone" => "Europe/London",
              "latitude" => 51.4964
    },
            "beat" => {
        "hostname" => "node03.test.org",
         "version" => "6.8.12",
            "name" => "node03.test.org"
    },
         "request" => "/test18.html",
           "input" => {
        "type" => "log"
    },
           "ident" => "-",
        "response" => "200",
     "httpversion" => "1.1"
}

　　提示：在node03的標准輸出上能夠看到我們剛才訪問httpd的訪問日志；

　　示例：配置filebeat將日志輸出到elasticsearch

　　重啟filebeat

　　驗證：訪問httpd看看elasticsearch中是否有保存httpd的訪問日志？

　　在elasticsearch中查看是否有新的index生成？

　　提示：可以看到es上有一個新的index生成；

　　查看es上存儲的日志內容

　　提示：從上面的返回的日志，存放在es中的日志並沒有做拆分，說明filebeat只是把httpd的日志當作message字段的值處理，並沒有去把ip地址信息做拆分；所以要想實現把日志內容拆分成不同字段，我們可以借助logstash，當然也可以在httpd上直接將日志格式記錄為json格式，然后再由filebeat將日志信息傳給es存儲；

　　示例：配置filebeat將收集的日志信息輸出到redis

 

　　提示：以上配置是配置filebeat將收集到的日志輸出到redis；這里需要注意一點，這個配置文件是yml格式的文件，需要注意下面的縮進關系要對其；其次filebeat它不支持多路輸出，例如，配置filebeat 輸出到logstash，又配置filebeat輸出到redis，這個它不支持，它支持單路輸出；

 　　重新啟動filebeat

　　用其他主機模擬訪問httpd

　　驗證：去node04上的redis 3號庫查看是否有key生成？是否有數據？

　　提示：可以看到此時redis的3號庫有指定key生成，對應key里面也存了httpd的訪問日志；

　　配置logstash到redis上讀數據，並刪除filebeat的冗余字段

[root@node03 ~]# cat /etc/logstash/conf.d/httpd-es.conf
input {
    redis {
        host => ["node04"]
        port => 6379
        password => "admin"
        key => "filebeat-node03-httpd-access_log"
        db => 3
        data_type => "list"
    }
}

filter {
    grok {
        match => {"message" => "%{HTTPD_COMBINEDLOG}" }
        remove_field => "message"
    }
    date {
        match => ["timestamp","dd/MMM/YYYY:H:m:s Z"]
        remove_field => "timestamp"
    }
    geoip {
        source => "clientip"
        target => "geoip"
        database => "/etc/logstash/geoip/GeoLite2-City.mmdb"
    }
    mutate {
        rename => ["geoip", "clientipInfo" ]
        remove_field => ["@metadata","prospector","input","beat","host","id","containerized"]
    }
}

output {
#    elasticsearch {
#       hosts => ["http://node01:9200","http://node02:9200"]
#       index => "httpd.log"
#       codec => "rubydebug"
#    }
    stdout { codec => "rubydebug" }
}

[root@node03 ~]# 

　　測試語法

　　啟動logstash

　　查看輸出到標准輸出的日志信息是否還有filebeat生成的多余字段？

　　提示：現在從redis讀出來的數據，然后經由logstash處理以后，filebeat生成的多余字段就刪除了；后續我們就可以直接將這些日志數據放到es中存儲；