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Self-Hosting Diun: Docker Image Update Notifications

Diun monitors your Docker images for updates. Get notified when new versions are available so you can update on your schedule.

diundockerupdatesmonitoring

The Update Problem


Your self-hosted apps run on container images. These images get updated with bug fixes, security patches, and new features. But how do you know when updates are available?


What Diun Does


Diun (Docker Image Update Notifier) monitors your running containers and checks their image registries for newer versions. When an update is available, you get notified.


How It Works


1. Diun scans your running containers

2. Checks the registry for each image

3. Compares local digest with remote digest

4. If different, sends a notification


Notification Channels


  • Email
  • Slack
  • Discord
  • Telegram
  • Gotify / Ntfy
  • Webhooks
  • Matrix

    • Configuration


    Diun can discover containers automatically:

    watch:

    workers: 10

    schedule: "0 6 * * *" # Check daily at 6 AM


    providers:

    docker:

    watchByDefault: true


    All running containers are monitored. Daily check for updates.


    Why Not Auto-Update?


    Diun notifies but doesn't update. This is intentional:

  • Updates can break things
  • You should test before updating
  • Review changelogs for breaking changes
  • Control when downtime happens

    • Update Workflow


    1. Diun notifies: "Nextcloud 28.0.1 → 28.0.2 available"

    2. Check the changelog for breaking changes

    3. Back up your data

    4. Pull the new image: podman pull nextcloud:28.0.2

    5. Restart the container

    6. Verify everything works


    Deployment


    1. Deploy Diun on TinyPod

    2. Configure notification channel

    3. Let it discover your containers

    4. Receive update notifications


    Resources: 1 CPU, 128 MB RAM. Very lightweight.