Relabel of Prometheus_ Configs and metric_ relabel_ Configs explanation and usage examples

Configuration definition

First look at the location of the two configurations ： 

global:
    ......
# A list of scrape configurations.
scrape_configs:
  # The job name assigned to scraped metrics by default.
  - job_name: <job_name>
    ........
    # List of target relabel configurations.
    relabel_configs:
      [ - <relabel_config> ... ]

    # List of metric relabel configurations.
    metric_relabel_configs:
      [ - <relabel_config> ... ]

<relabel_config> relabel_config | Prometheus

# The source labels select values from existing labels. Their content is concatenated
# using the configured separator and matched against the configured regular expression
# for the replace, keep, and drop actions.
[ source_labels: '[' <labelname> [, ...] ']' ]

# Separator placed between concatenated source label values.
[ separator: <string> | default = ; ]

# Label to which the resulting value is written in a replace action.
# It is mandatory for replace actions. Regex capture groups are available.
[ target_label: <labelname> ]

# Regular expression against which the extracted value is matched.
[ regex: <regex> | default = (.*) ]

# Modulus to take of the hash of the source label values.
[ modulus: <int> ]

# Replacement value against which a regex replace is performed if the
# regular expression matches. Regex capture groups are available.
[ replacement: <string> | default = $1 ]

# Action to perform based on regex matching.
[ action: <relabel_action> | default = replace ]

difference ：relabel_configs Used to grab metrics Modified before target Existing labels for , Existing tags, that is, in the configuration source_labels Include （ Can be obtained from Prometheus UI Of target Page view ）__address__、__meta_filepath、__metrics_path__、__scheme__、job as well as target Other labels added manually in .

metric_relabel_configs Used to modify the... Obtained after grabbing metric The label of , Usable source_labels Include instance、job already target Other labels added manually in .

Usage examples

Create a new label using an existing label

For example, add a... To the indicator IP label , Use the following configuration to achieve ：

# relabel_config
  - job_name: 'node'
    file_sd_configs:
    - refresh_interval: 1m
      files:
      - node_targets.yml
    relabel_configs:
      - source_labels: ['__address__']
        regex: (.*):.*
        target_label: 'IP'

Or use metric_relabel_configs, Note that the configuration is incorrect up Indicator effectiveness .

# metric_relabel_config
  - job_name: 'node'
    file_sd_configs:
    - refresh_interval: 1m
      files:
      - node_targets.yml
    metric_relabel_configs:
      - source_labels: ['instance']
        regex: (.*):.*
        target_label: 'IP'

To a group job Add a new label to the indicator

For example, add a public tag env=“test”：

  - job_name: 'node'
    file_sd_configs:
    - refresh_interval: 1m
      files:
      - config/node_targets.yml
    relabel_configs:
      - target_label: 'env'
        replacement: 'test'

Use here relabel_configs perhaps metric_relabel_configs All possible , Because it doesn't involve source_labels The string is directly used instead of .