DIUN Viewer

DIUN Viewer is a lightweight web dashboard for DIUN (Docker Image Update Notifier).
It provides a simple UI to inspect images, view update events, and correlate image digests with DIUN webhook notifications.

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Features

• Web UI for DIUN images and events
• Status badge per image (up to date / outdated)
• Persistent event storage in a JSON file
• DIUN webhook ingestion
• Automatic cleanup of obsolete events based on current digests
• Auto‑refresh of data every few minutes
• No external database, no build step, no heavy frameworks

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Architecture

• Backend: Go HTTP server

  • Serves static frontend
  • Uses Docker SDK (ImageList) to list local Docker images
  • Uses Diun image list -raw to list Diun image list
  • Receives DIUN webhook events
  • Stores events in events.json
  • Exposes a small JSON REST API (/api/images, /api/events, etc.)

• Frontend: Static HTML + JS

  • Bootstrap 5 + AdminLTE 4 layout
  • jQuery + DataTables for tables
  • FontAwesome + Bootstrap Icons for icons
  • Vanilla JS (app.js) for logic

High‑level flow:

1. DIUN sends webhook events to /api/diun-webhook
2. Go server appends events to events.json
3. Frontend calls /api/events , /api/images and /api/diunImages
4. Frontend correlates Docker image with Diun Images and renders status badges

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Backend

API Endpoints

• GET /api/images
  Returns Docker SDK (ImageList) to list local Docker images.

• GET /api/diunImages
  Returns Diun images by diun image list -raw .

• GET /api/events
  Returns stored events after cleaning out entries whose digest is no longer present in DIUN’s current image list.

• POST /api/events/delete
  Deletes events:

  • Empty array [] → delete all events
  • Array of IDs [1, 2, 3] → delete only those events

• POST /api/diun-webhook
  Receives DIUN webhook JSON and appends it to the event store.

Configuration

The server reads a simple key/value config file diunViewer.cfg, for example:

PUBLIC_DIR=/tools/public
LISTEN_PORT=80
EVENTS_FILE=/data/events.json
DIUN_BINARY=diun
LOG_LEVEL=debug

Configuration Keys

• PUBLIC_DIR – directory containing static frontend files
• LISTEN_PORT – port for the HTTP server (e.g. 80)
• EVENTS_FILE – path to the JSON file used to persist events
• DIUN_BINARY – path or name of the DIUN binary
• LOG_LEVEL – info or debug

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Frontend

Technologies

• Bootstrap 5 – layout and components
• AdminLTE 4 – sidebar and dashboard styling
• jQuery 3.6 – DOM helpers
• DataTables 1.13 – sortable/searchable tables
• FontAwesome 5 and Bootstrap Icons – icons
• Vanilla JavaScript – application logic (app.js)

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Installation

Build and run (Go)

go build -o diunViewer
./diunViewer

Ensure:

• The config file (e.g. /tools/diunViewer.cfg) exists and is valid
• PUBLIC_DIR points to the directory containing index.html, app.js, CSS, etc.
• DIUN_BINARY is reachable (in PATH or full path)

DIUN Webhook Configuration

webhook only if you want to have it in Diun Viewer

- DIUN_NOTIF_WEBHOOK_ENDPOINT=http://192.168.1.26/api/diun-webhook
- DIUN_NOTIF_WEBHOOK_METHOD=POST
- DIUN_NOTIF_WEBHOOK_TIMEOUT=10s

Docker Example

services:
  diun:
    image: crazymax/diun:latest
    container_name: diun
    restart: always

    networks:
      qnet-static-eth0-79e6cc:
        ipv4_address: 192.168.1.26

    mac_address: 02:42:17:48:85:49

    volumes:
      - /share/Container/Diun/data:/data
      - /var/run/docker.sock:/var/run/docker.sock
      - /share/Container/Diun/tools:/tools

    ports:
      - "80:80"

    dns:
      - 192.168.1.53
      - 8.8.8.8

    environment:
      - TZ=Europe/Zagreb
      - DIUN_PROVIDERS_DOCKER=true
      - DIUN_PROVIDERS_DOCKER_WATCHBYDEFAULT=true
      - DIUN_PROVIDERS_DOCKER_WATCHSTOPPED=true
      - DIUN_WATCH_SCHEDULE=0 */6 * * *
      - DIUN_NOTIF_WEBHOOK_ENDPOINT=http://192.168.1.26/api/diun-webhook
      - DIUN_NOTIF_WEBHOOK_METHOD=POST
      - DIUN_NOTIF_WEBHOOK_TIMEOUT=10s

    entrypoint: ["/tools/entrypoint.sh"]

networks:
  qnet-static-eth0-79e6cc:
    external: true

Injecting DIUN Viewer Into the DIUN Docker Image

DIUN Viewer is not baked into the crazymax/diun image.
Instead, it is injected at runtime using a bind-mounted /tools directory and a custom entrypoint.sh.

This approach allows the DIUN container to be updated freely while keeping:

• The DIUN Viewer binary
• The configuration file
• The event storage
• The custom entrypoint script

fully persistent and untouched.

How It Works

1. A host directory is mounted into the container at /tools:

/share/Container/Diun/tools:/tools

This directory contains:

• diunViewer — the Go DIUN Viewer server binary
• diunViewer.cfg — configuration file
• entrypoint.sh — custom startup script

The container’s entrypoint is overridden:

entrypoint: ["/tools/entrypoint.sh"]

The custom entrypoint:

• Starts the DIUN Viewer webserver in the background
• Starts the official DIUN binary normally

Result

• The DIUN container runs normally.
• DIUN Viewer runs alongside it inside the same container.
• Updates to the DIUN image do not affect the Viewer.
• All Viewer files remain persistent on the host.
• No modification of the DIUN image is required.

This method keeps the DIUN container stateless while allowing DIUN Viewer to coexist safely and survive upgrades.

License

MIT License
See LICENSE for details.

Images	Events

Image Details