ELK logstash 配置语法

数据类型

logstash支持的数据类型有：

• array
  数组能够是单个或者多个字符串值。
  path => [ "/var/log/messages", "/var/log/*.log" ]
  path => "/data/mysql/mysql.log"
  若是指定了屡次，追加数组。此实例path数组包含三个字符串元素。
• boolean
  布尔值必须是TRUE或者false。true和false不能有引号。
  ssl_enable => true
• bytes
  指定字节单位。支持的单位有SI (k M G T P E Z Y) 和 Binary (Ki Mi Gi Ti Pi Ei Zi Yi)。Binary单位基于1024，SI单位基于1000。不区分大小写和忽略值与单位之间的空格。若是没有指定单位，默认是byte。
  my_bytes => "1113" # 1113 bytes
  my_bytes => "10MiB" # 10485760 bytes
  my_bytes => "100kib" # 102400 bytes
  my_bytes => "180 mb" # 180000000 bytes
• Codec
  logstash编码名称用来表示数据编码。用于input和output段。便于数据的处理。若是input和output使用合适的编码，就无需单独的filter对数据进行处理。
  codec => "json"
• hash
  键值对，注意多个键值对用空格分隔，而不是逗号。
  match => {
  "field1" => "value1"
  "field2" => "value2"
  ... }
• number
  必须是有效的数值，浮点数或者整数。
  port => 33
• password
  一个单独的字符串。
  my_password => "password"
• path
  一个表明有效的操做系统路径。
  my_path => "/tmp/logstash"
• string
  name => "Hello world"
  name => 'It\'s a beautiful day'

字段引用

logstash字段引用语法。要在 Logstash 配置中使用字段的值，只须要把字段的名字写在中括号 [] 里就好了，这就叫字段引用。还需注意字段层次。若是引用的是一个顶级字段，能够省略[]，直接指定字段名。要引用嵌套的字段，须要指定完整的路径，如[top-level field][nested field]。

下面有五个顶级字段(agent, ip, request, response, ua) 和三个嵌套字段 (status, bytes, os)。

{ "agent": "Mozilla/5.0 (compatible; MSIE 9.0)", "ip": "192.168.24.44", "request": "/index.html" "response": { "status": 200, "bytes": 52353 }, "ua": { "os": "<a href="http://www.ttlsa.com/windows/" title="windows"target="_blank">Windows</a> 7" } }

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{   "agent": "Mozilla/5.0 (compatible; MSIE 9.0)",   "ip": "192.168.24.44",   "request": "/index.html"   "response": {     "status": 200,     "bytes": 52353   },   "ua": {     "os": "Windows 7"   } }

为了引用os字段，需指定[ua][os]。引用顶级字段如request，能够简单指定request便可。

sprintf格式

字段引用格式也能够用于logstash调用sprintf格式。这种格式能够从其余字符串中引用字段值。如：

output { statsd { increment => "apache.%{[response][status]}" } }

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output {   statsd {     increment => "apache.%{[response][status]}"   } }

也能够格式化时间。如：

output { file { path => "/var/log/%{type}.%{+yyyy.MM.dd.HH}" } }

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output {   file {     path => "/var/log/%{type}.%{+yyyy.MM.dd.HH}"   } }

 

条件判断

使用条件来决定filter和output处理特定的事件。

logstash条件相似于编程语言。条件支持if、else if、else语句，能够嵌套。

条件语法以下：

if EXPRESSION { ... } else if EXPRESSION { ... } else { ... }

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if EXPRESSION {   ... } else if EXPRESSION {   ... } else {   ... }

比较操做有：

• 相等: ==, !=, <, >, <=, >=
• 正则: =~(匹配正则), !~(不匹配正则)
• 包含: in(包含), not in(不包含)

布尔操做：

• and(与), or(或), nand(非与), xor(非或)

一元运算符：

• !(取反)
• ()(复合表达式), !()(对复合表达式结果取反)

如mutate filter删除secret字段对于action是login的：

filter { if [action] == "login" { mutate { remove => "secret" } } }

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filter {   if [action] == "login" {     mutate { remove => "secret" }   } }

在一个条件里指定多个表达式：

output { # Send production errors to pagerduty if [loglevel] == "ERROR" and [deployment] == "production" { pagerduty { ... } } }

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output {   # Send production errors to pagerduty   if [loglevel] == "ERROR" and [deployment] == "production" {     pagerduty {     ...     }   } }

在in条件，能够比较字段值：

filter { if [foo] in [foobar] { mutate { add_tag => "field in field" } } if [foo] in "foo" { mutate { add_tag => "field in string" } } if "hello" in [greeting] { mutate { add_tag => "string in field" } } if [foo] in ["hello", "world", "foo"] { mutate { add_tag => "field in list" } } if [missing] in [alsomissing] { mutate { add_tag => "shouldnotexist" } } if !("foo" in ["hello", "world"]) { mutate { add_tag => "shouldexist" } } }

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filter {   if [foo] in [foobar] {     mutate { add_tag => "field in field" }   }   if [foo] in "foo" {     mutate { add_tag => "field in string" }   }   if "hello" in [greeting] {     mutate { add_tag => "string in field" }   }   if [foo] in ["hello", "world", "foo"] {     mutate { add_tag => "field in list" }   }   if [missing] in [alsomissing] {     mutate { add_tag => "shouldnotexist" }   }   if !("foo" in ["hello", "world"]) {     mutate { add_tag => "shouldexist" }   } }

 

output { if "_grokparsefailure" not in [tags] { elasticsearch { ... } } }

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output {   if "_grokparsefailure" not in [tags] {     elasticsearch { ... }   } }

字段引用、sprintf格式、条件判断只能用于filter和output，不能用于input。

@metadata字段

在logstash1.5版本开始，有一个特殊的字段，叫作@metadata。@metadata包含的内容不会做为事件的一部分输出。

input { stdin { } } filter { mutate { add_field => { "show" => "This data will be in the output" } } mutate { add_field => { "[@metadata][test]" => "Hello" } } mutate { add_field => { "[@metadata][no_show]" => "This data will not be in the output" } } } output { if [@metadata][test] == "Hello" { stdout { codec => rubydebug } } }

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input { stdin { } }   filter {   mutate { add_field => { "show" => "This data will be in the output" } }   mutate { add_field => { "[@metadata][test]" => "Hello" } }   mutate { add_field => { "[@metadata][no_show]" => "This data will not be in the output" } } }   output {   if [@metadata][test] == "Hello" {     stdout { codec => rubydebug }   } }

查看输出：

$ bin/logstash -f ../test.conf Logstash startup completed asdf { "message" => "asdf", "@version" => "1", "@timestamp" => "2015-03-18T23:09:29.595Z", "host" => "www.ttlsa.com", "show" => "This data will be in the output" }

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$ bin/logstash -f ../test.conf Logstash startup completed asdf {        "message" => "asdf",       "@version" => "1",     "@timestamp" => "2015-03-18T23:09:29.595Z",           "host" => "www.ttlsa.com",           "show" => "This data will be in the output" }

"asdf"变成message字段内容。条件与@metadata内嵌的test字段内容判断成功，可是输出并无展现@metadata字段和其内容。

不过，若是指定了metadata => true，rubydebug codec容许显示@metadata字段的内容。

stdout { codec => rubydebug { metadata => true } }

1	stdout { codec => rubydebug { metadata => true } }

下面是输出的内容：

$ bin/logstash -f ../test.conf Logstash startup completed asdf { "message" => "asdf", "@version" => "1", "@timestamp" => "2015-03-18T23:10:19.859Z", "host" => "www.ttlsa.com", "show" => "This data will be in the output", "@metadata" => { "test" => "Hello", "no_show" => "This data will not be in the output" } }

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$ bin/logstash -f ../test.conf Logstash startup completed asdf {        "message" => "asdf",       "@version" => "1",     "@timestamp" => "2015-03-18T23:10:19.859Z",           "host" => "www.ttlsa.com",           "show" => "This data will be in the output",      "@metadata" => {            "test" => "Hello",         "no_show" => "This data will not be in the output"     } }

能够看到@metadata字段及其子字段内容。

注意：只有rubydebug codec能够显示@metadata字段内容。

确保@metadata字段临时须要，不但愿最终输出。最多见的情景是filter的时间字段，须要一临时的时间戳。如：

input { stdin { } } filter { grok { match => [ "message", "%{HTTPDATE:[@metadata][timestamp]}" ] } date { match => [ "[@metadata][timestamp]", "dd/MMM/yyyy:HH:mm:ss Z" ] } } output { stdout { codec => rubydebug } }

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input { stdin { } }   filter {   grok { match => [ "message", "%{HTTPDATE:[@metadata][timestamp]}" ] }   date { match => [ "[@metadata][timestamp]", "dd/MMM/yyyy:HH:mm:ss Z" ] } }   output {   stdout { codec => rubydebug } }

输出结果：

$ bin/logstash -f ../test.conf Logstash startup completed 02/Mar/2014:15:36:43 +0100 { "message" => "02/Mar/2014:15:36:43 +0100", "@version" => "1", "@timestamp" => "2014-03-02T14:36:43.000Z", "host" => "example.com" }

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$ bin/logstash -f ../test.conf Logstash startup completed 02/Mar/2014:15:36:43 +0100 {        "message" => "02/Mar/2014:15:36:43 +0100",       "@version" => "1",     "@timestamp" => "2014-03-02T14:36:43.000Z",           "host" => "example.com" }