https://prometheus.io/docs/prometheus/latest/configuration/configuration/#file_sd_config
File-based service discovery provides a more generic way to configure static targets and serves as an interface to plug in custom service discovery mechanisms.

It reads a set of files containing a list of zero or more  static_config s. 
Changes to all defined files are detected via disk watches and applied immediately. 
Files may be provided in YAML or JSON format. 
Only changes resulting in well-formed target groups are applied.




[
  {
    "targets": [ "host", ... ],
    "labels": {
      "labelname": "labelvalue", ...
    }
  },
  ...
]

- targets:
  [ - 'host' ]
  labels:
    [ labelname: labelvalue ... ]




# Patterns for files from which target groups are extracted.
files:
  [ -  filename_pattern ... ]

# Refresh interval to re-read the files.
[ refresh_interval:  duration | default = 5m ]

filename_pattern  may be a path ending in .json, .yml or .yaml

The last path segment may contain a single * that matches any character sequence, e.g. my/path/tg_*.json.





./promtool check config prometheus.yml


  - job_name: 'nodes'
    file_sd_configs:
    - files:                                               
      - targets/nodes-*.yaml  
      refresh_interval: 2m 
    scrape_interval: 15s
  - job_name: 'elasticsearch'
    scrape_interval: 15s
    scrape_timeout:  10s
    metrics_path: "/metrics"
    file_sd_configs:
    - files:                                               
      - targets/elasticsearch.yml  
      refresh_interval: 2m 
  - job_name: 'kafka'
    scrape_interval: 15s
    scrape_timeout:  10s
    file_sd_configs:
    - files:                                               
      - targets/kafka.yml  
      refresh_interval: 2m 


  - job_name: 'nacos'
    scrape_interval: 15s
    scrape_timeout:  10s
    metrics_path: "/nacos/actuator/prometheus"
    file_sd_configs:
    - files:                                               
      - targets/nacos.yml  
      refresh_interval: 2m




elasticsearch.yml 
- targets:
  - 192.168.1.10:9114
  - 192.168.1.11:9114
  - 192.168.1.12:9114
  labels:
    app: elasticsearch




elasticsearch_cluster_health_up

elasticsearch_cluster_health_up{app="elasticsearch",instance="192.168.1.10:9114",job="elasticsearch"}	1
elasticsearch_cluster_health_up{app="elasticsearch",instance="192.168.1.11:9114",job="elasticsearch"}	1
elasticsearch_cluster_health_up{app="elasticsearch",instance="192.168.1.12:9114",job="elasticsearch"}	1


app="elasticsearch"
job="elasticsearch"





  - job_name: 'file_sd_demo'
    # metrics_path: '/actuator/prometheus'
    file_sd_configs:
    - files:                                               
      - targets/app-*.json  
      refresh_interval: 5s


app-1.json
[{"targets":["codefun007.xyz"],"labels":{"app":"web1"}}]

app-2.json
[{"targets":["codefun007.xyz"],"labels":{"app":"web2"}}]

app-3.json
[{"targets":["codefun007.xyz"],"labels":{"app":"web3","job":"web3"}}]

注意 json 数组 格式 

labels 的标签会覆盖 外面的配置

total_pv
total_pv{app="web1", instance="codefun007.xyz:80", job="file_sd_demo"} 3884967
total_pv{app="web2", instance="codefun007.xyz:80", job="file_sd_demo"} 3884966
total_pv{app="web3", instance="codefun007.xyz:80", job="web3"} 3884967