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三、prometheus之relabel详解

作者:互联网

一、relabel简介

为了更好的识别监控指标,便于后期调用数据绘图、告警等需求,prometheus支持对发现的目标进行label修改,可以在目标被抓取之前动态重写目标的标签集。每个抓取配置可以配置多个重新标记步骤。它们按照它们在配置文件中出现的顺序应用于每个目标的标签集。

 

除了配置的每个目标标签之外,prometheus还会自动添加几个标签:

job标签:设置为job_name相应的抓取配置的值。

instance标签:__address__设置为目标的地址<host>:<port>。重新标记后,如果在重新标记期间未设置标签,则默认将__address__标签值赋值给instance。

__schema__:协议类型

__metrics_path:抓取指标数的url

__scrape_interval__:scrape抓取数据时间间隔(秒)

__scrape_timeout__:scrape超时时间(秒)

 

__meta_在重新标记阶段可能会提供带有前缀的附加标签。它们由提供目标的服务发现机制设置,并且因机制而异。

__目标重新标记完成后,将从标签集中删除以开头的标签。

如果重新标记步骤只需要临时存储标签值(作为后续重新标记步骤的输入),可以使用__tmp标签名称前缀。这个前缀保证不会被 Prometheus 本身使用。

 

常用的在以下两个阶段可以重新标记:

relabel_configs:在采集之前(比如在采集数据之前重新定义元标签),可以使用relabel_configs添加一些标签、也可以只采集特定目标或过滤目标

metric_relabel_configs:如果是已经抓取到指标数据时,可以使用metric_relabel_configs做最后的重新标记和过滤

 二、relabel_configs配置

source_labels:源标签,没有经过relabel处理之前的标签名字

target_labels:通过relabel处理之后的标签名字

separator:源标签的值的连接分隔符。默认是";"

module:取源标签值散列的模数

regex:正则表达式,匹配源标签的值。默认是(.*)

replacement:通过分组替换后标签(target_label)对应的值。默认是$1

action:根据正则表达式匹配执行的动作。默认是replace

 三、常用的action案例

在开始之前准备prometheus配置文件

scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: "prometheus"

    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.

    static_configs:
      - targets: ["localhost:9090"]

  - job_name: "nodes"
    static_configs:
      - targets:
        - 192.168.88.201:9100
        labels:
          __hostname__: node01
          __region_id__: "shanghai"
          __zone__: a
      - targets:
        - 192.168.88.202:9100
        labels:
          __hostname__: node02
          __region_id__: "beijing"
          __zone__: b

查看target

 因为我们的label都是以__开头的,目标重新标签之后,以__开头的标签将从标签集中删除的。

 3.1、replace

将labels中的__hostname__替换为node_name

scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: "prometheus"

    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.

    static_configs:
      - targets: ["localhost:9090"]

  - job_name: "nodes"
    static_configs:
      - targets:
        - 192.168.88.201:9100
        labels:
          __hostname__: node01
          __region_id__: "shanghai"
          __zone__: a
      - targets:
        - 192.168.88.202:9100
        labels:
          __hostname__: node02
          __region_id__: "beijing"
          __zone__: b
    relabel_configs:
    - source_labels:
      - "__hostname__"
      regex: "(.*)"
      target_label: "node_name"
      action: replace
      replacement: $1

重启服务查看target信息如下

说下上面的配置: source_labels指定我们需要处理的源标签, target_labels指定了我们要replace后的标签名字, action指定relabel动作,这里使用replace替换动作。 regex去匹配源标签(__hostname__)的值,"(.*)"代表__hostname__这个标签是什么值都匹配的,然后replacement指定的替换后的标签(target_label)对应的数值。采用正则引用方式获取的。

3.2、keep

只要source_labels的值匹配node01的实例才会被采集数据,其他实例不会采集

scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: "prometheus"

    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.

    static_configs:
      - targets: ["localhost:9090"]

  - job_name: "nodes"
    static_configs:
      - targets:
        - 192.168.88.201:9100
        labels:
          __hostname__: node01
          __region_id__: "shanghai"
          __zone__: a
      - targets:
        - 192.168.88.202:9100
        labels:
          __hostname__: node02
          __region_id__: "beijing"
          __zone__: b
    relabel_configs:
    - source_labels:
      - "__hostname__"
      regex: "node01"
      action: keep

target如下图

 3.3、drop

在keep的基础上把action修改为drop

target如下图

 action为drop,其实和keep是相似的, 不过是相反的, 只要source_labels的值匹配regex(node01)的实例不会被采集。 其他的实例会被采集。

3.4、labelmap

 所有被regex __(.*)__匹配到的标签名,复制匹配到的标签的值,通过replacement分组引用$1,然后创建匹配到的标签集

修改配置如下:

scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: "prometheus"

    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.

    static_configs:
      - targets: ["localhost:9090"]

  - job_name: "nodes"
    static_configs:
      - targets:
        - 192.168.88.201:9100
        labels:
          __hostname__: node01
          __region_id__: "shanghai"
          __zone__: a
      - targets:
        - 192.168.88.202:9100
        labels:
          __hostname__: node02
          __region_id__: "beijing"
          __zone__: b
    relabel_configs:
    - regex: "__(.*)__"
      action: labelmap

查看target

 3.5、labelkeep

先给每个实例打上几个label,配置文件如下:

scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: "prometheus"

    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.

    static_configs:
      - targets: ["localhost:9090"]

  - job_name: "nodes"
    static_configs:
      - targets:
        - 192.168.88.201:9100
        labels:
          __hostname__: node01
          __region_id__: "shanghai"
          __zone__: a
      - targets:
        - 192.168.88.202:9100
        labels:
          __hostname__: node02
          __region_id__: "beijing"
          __zone__: b
    relabel_configs:
    - source_labels:
      - "__hostname__"
      regex: (.*)
      target_label: hostname
      action: replace
      replacement: $1
    - source_labels:
      - "__region_id__"
      regex: (.*)
      target_label: region_id
      action: replace
      replacement: $1
    - source_labels:
      - "__zone__"
      regex: (.*)
      target_label: zone
      action: replace
      replacement: $1

查看target如下

添加labelkeep配置,保留正则__.*__|job匹配到的标签,没有匹配到的则删除

scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: "prometheus"

    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.

    static_configs:
      - targets: ["localhost:9090"]

  - job_name: "nodes"
    static_configs:
      - targets:
        - 192.168.88.201:9100
        labels:
          __hostname__: node01
          __region_id__: "shanghai"
          __zone__: a
      - targets:
        - 192.168.88.202:9100
        labels:
          __hostname__: node02
          __region_id__: "beijing"
          __zone__: b
    relabel_configs:
    - source_labels:
      - "__hostname__"
      regex: (.*)
      target_label: hostname
      action: replace
      replacement: $1
    - source_labels:
      - "__region_id__"
      regex: (.*)
      target_label: region_id
      action: replace
      replacement: $1
    - source_labels:
      - "__zone__"
      regex: (.*)
      target_label: zone
      action: replace
      replacement: $1
    - action: labelkeep
      regex: "__.*__|job"

查看target,只有instance和job标签,instance标签是prometheus自动生成的

 3.6、labeldrop

修改labeldrop配置,删除正则region|zone 匹配到的标签,不匹配的保留

scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: "prometheus"

    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.

    static_configs:
      - targets: ["localhost:9090"]

  - job_name: "nodes"
    static_configs:
      - targets:
        - 192.168.88.201:9100
        labels:
          __hostname__: node01
          __region_id__: "shanghai"
          __zone__: a
      - targets:
        - 192.168.88.202:9100
        labels:
          __hostname__: node02
          __region_id__: "beijing"
          __zone__: b
    relabel_configs:
    - source_labels:
      - "__hostname__"
      regex: (.*)
      target_label: hostname
      action: replace
      replacement: $1
    - source_labels:
      - "__region_id__"
      regex: (.*)
      target_label: region_id
      action: replace
      replacement: $1
    - source_labels:
      - "__zone__"
      regex: (.*)
      target_label: zone
      action: replace
      replacement: $1
    - action: labeldrop
      regex: "region_id|zone"

查看target,region和zone标签已被删除,但hostname标签还在

 

标签:__,regex,标签,labels,relabel,job,prometheus,详解,configs
来源: https://www.cnblogs.com/zhrx/p/15978104.html