relabel_config重新标记是一个功能强大的工具，可以在目标的标签集被抓取之前重写它，每个采集配置可以配置多个重写标签设置，并按照配置的顺序来应用于每个目标的标签集。
目标重新标签之后，以__开头的标签将从标签集中删除的。
如果使用只需要临时的存储临时标签值的，可以使用_tmp作为前缀标识。
在测试前，同步下配置文件如下。
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: "node"
file_sd_configs:
- refresh_interval: 1m
files:
- "/usr/local/prometheus/prometheus/conf/node*.yml"
[root@node00 prometheus]# cat conf/node-dis.yml
- targets:
- "192.168.100.10:20001"
labels:
__hostname__: node00
__businees_line__: "line_a"
__region_id__: "cn-beijing"
__availability_zone__: "a"
- targets:
- "192.168.100.11:20001"
labels:
__hostname__: node01
__businees_line__: "line_a"
__region_id__: "cn-beijing"
__availability_zone__: "a"
- targets:
- "192.168.100.12:20001"
labels:
__hostname__: node02
__businees_line__: "line_c"
__region_id__: "cn-beijing"
__availability_zone__: "b"
此时如果查看target信息，如下图。
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。
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: "node"
file_sd_configs:
- refresh_interval: 1m
files:
- "/usr/local/prometheus/prometheus/conf/node*.yml"
relabel_configs:
- source_labels:
- "__hostname__"
regex: "(.*)"
target_label: "nodename"
action: replace
replacement: "$1"
重启服务查看target信息如下图：
说下上面的配置： source_labels指定我们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。
这里修改下上面的正则表达式为 ‘’regex: "(node00)"‘的时候可以看到如下图。
修改配置文件
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: "node"
file_sd_configs:
- refresh_interval: 1m
files:
- "/usr/local/prometheus/prometheus/conf/node*.yml"
target如下图
修改配置文件如下
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: "node"
file_sd_configs:
- refresh_interval: 1m
files:
- "/usr/local/prometheus/prometheus/conf/node*.yml"
relabel_configs:
- source_labels:
- "__hostname__"
regex: "node00"
action: keep
target如下图
action为keep，只要source_labels的值匹配regex（node00）的实例才能会被采集。 其他的实例不会被采集。
在上面的基础上，修改action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（node00）的实例不会被采集。 其他的实例会被采集。
我们的基础信息里面有__region_id__和__availability_zone__，但是我想融合2个字段在一起，可以通过replace来实现。
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: "node"
file_sd_configs:
- refresh_interval: 1m
files:
- "/usr/local/prometheus/prometheus/conf/node*.yml"
relabel_configs:
- source_labels:
- "__region_id__"
- "__availability_zone__"
separator: "-"
regex: "(.*)"
target_label: "region_zone"
action: replace
replacement: "$1"
target如下图：
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: "node"
file_sd_configs:
- refresh_interval: 1m
files:
- "/usr/local/prometheus/prometheus/conf/node*.yml"
relabel_configs:
- source_labels:
- "__hostname__"
regex: "(.*)"
target_label: "nodename"
action: replace
replacement: "$1"
- source_labels:
- "__businees_line__"
regex: "(.*)"
target_label: "businees_line"
action: replace
replacement: "$1"
- source_labels:
- "__datacenter__"
regex: "(.*)"
target_label: "datacenter"
action: replace
replacement: "$1"
target如下图
修改配置文件如下
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: "node"
file_sd_configs:
- refresh_interval: 1m
files:
- "/usr/local/prometheus/prometheus/conf/node*.yml"
relabel_configs:
- source_labels:
- "__hostname__"
regex: "(.*)"
target_label: "nodename"
action: replace
replacement: "$1"
- source_labels:
- "__businees_line__"
regex: "(.*)"
target_label: "businees_line"
action: replace
replacement: "$1"
- source_labels:
- "__datacenter__"
regex: "(.*)"
target_label: "datacenter"
action: replace
replacement: "$1"
- regex: "(nodename|datacenter)"
action: labeldrop
target如下图
prometheus学习系列六： Prometheus relabel配置
原文：https://www.cnblogs.com/zhaojiedi1992/p/zhaojiedi_liunx_61_prometheus_relabel.html