Quartz 4

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Config File

2 min read

How to write the config file

/etc/prometheus/prometheus.yml

Main Sections

1. global

Applies to all jobs unless overridden:

global:   scrape_interval: 15s       # How often Prometheus pulls metrics   evaluation_interval: 15s   # How often rules/alerts are checked   
scrape_timeout: 10s        # How long to wait before a scrape is considered failed external_labels:       
	monitor: 'example'     # Extra label(s) added to every metric

Key setting: scrape_interval — shorter means fresher data but more load.

2. alerting

Tells Prometheus where your Alertmanager is:

alerting:
  alertmanagers:
  - static_configs:
    - targets: ['localhost:9093']

If you’re not using Alertmanager, you can remove or ignore this section.

3. rule_files

Lists files that contain recording rules or alerting rules:

rule_files:
  - "first_rules.yml"

Rules are YAML files that define conditions and create new metrics or alerts.

4. scrape_configs

Defines what targets Prometheus scrapes:

scrape_configs:
  - job_name: 'prometheus'
    scrape_interval: 5s       # Overrides global for this job
    scrape_timeout: 5s
    static_configs:
      - targets: ['localhost:9090']

Important keys:

  • job_name → Logical label grouping (appears as job= in metrics)

  • targets → List of host:port where metrics live

  • metrics_path (default /metrics) → Path to scrape

  • scheme (default http) → Change to https if needed

You can add more jobs for other exporters, e.g.:

  - job_name: 'proxmox-node'
    static_configs:
      - targets: ['192.168.1.10:9100']

The “prometheus” job is only for showing the scrape performance, target health etc, not CPU and RAM. You need to install node_exporter and use port 9100 for that.

How to define your own config

  1. Set global settings for scrape/evaluation intervals.

  2. List each target (exporter) under scrape_configs with a job_name.

  3. (Optional) Override intervals per job if you want more or less frequent scrapes.

  4. (Optional) Add rules via rule_files.

  5. If using Alertmanager, add it under alerting.

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