backmon watches backup files in filesystems and S3-compatible object storage and turns them into Prometheus metrics you can graph and alert on.
Features
Watch backup files on local disks, in S3-compatible storage like AWS S3 and MinIO, or in Google Cloud Storage.
mysql/2026-10-13.sql.gz 1.8 GB
mysql/2026-10-12.sql.gz 1.8 GB
photos/2026-w41.tar 48.2 GBGet notified when a backup is missing, too small or too old.
One instance, many storages, each with its own rules.
Presence, size, age and duration of every backup, ready for Prometheus and Grafana.
Remove outdated backup files automatically so storage does not fill up.
Download backup files from one place instead of logging into every storage.
How it works
Tell backmon which disks to watch and what a healthy backup group looks like.
environments:
aws-test-environment:
disks:
include:
- s3-photos
region: eu-central-1
On every interval it inspects your storages and exposes the result for Prometheus.
backmon_backup_file_count{disk="mysql-dumps"} 7
backmon_backup_file_count_max{disk="mysql-dumps"} 7
backmon_backup_file_count{disk="s3-photos"} 0
backmon_backup_file_count_max{disk="s3-photos"} 4
A Prometheus rule on those metrics notifies your team before you ever need the backup.
- alert: BackupMissing
expr: backmon_backup_file_count
< backmon_backup_file_count_max
for: 15m
FIRING disk="s3-photos"
Install
docker run -p 8000:8000 \
-v "$PWD/config.yaml:/etc/backmon/config.yaml" \
dreitier/backmonhelm repo add dreitier https://dreitier.github.io/helm-charts/
helm repo update
helm install backmon dreitier/backmonThe presence, size and timestamps of recurring backup files in a filesystem, an S3-compatible object storage or Google Cloud Storage. It does not create backups.
Yes. Any S3-compatible storage works, including AWS S3 and MinIO.
backmon exports Prometheus metrics. Use Alertmanager rules on those metrics to notify your team.