Restic snapshot metrics to Prometheus Pushgateway

Simple script to push metrics of the latest restic backup snapshot to Prometheus Pushgateway.

There are also Prometheus exporters for restic, but the underlying restic stats command they use comes with high CPU and memory consumption (#2126). Since I'm only interested in the last snapshot for alerting rather than creating detailed dashboards, regularly pushing the latest snapshot infos seemed to be the easier route.

Usage

The scripts expects environment variables to access the restic repository, and the Pushgateway URL as parameter:

usage: restic_metrics_to_pushgateway.py [-h] [--loglevel] --pushgateway_url URL [--tls_skip_verify]

Send metrics of latest restic snapshot to Prometheus Pushgateway.

options:
  -h, --help            show this help message and exit
  --loglevel LEVEL      log level ({CRITICAL,ERROR,WARNING,INFO,DEBUG}, default: INFO)
  --pushgateway_url URL Prometheus Pushgateway URL
                        (e.g. "http://pushgateway.example.org:9091/metrics/job/some_job/instance/some_instance")
  --tls_skip_verify     Skip TLS certificate verification.

Example Prometheus alerting rule

groups:
  - name: restic
    rules:
      - alert: ResticOutdatedBackup
        annotations:
          summary: Restic backup on {{ $labels.hostname }} is outdated
          description: |
            Restic backup on {{ $labels.hostname }} is outdated:
            Last backup: {{ $value | humanizeTimestamp }}
            User: {{ $labels.username }}
            Paths: {{ $labels.paths }}
            Tags: {{ $labels.tags }}
        # 86400 = 24 hours
        expr: time() - restic_last_snapshot{hostname!="ares"} > 86400
        for: 24h
        labels:
          severity: critical

License

MIT