WUD Keeps an Eye on Your Containers So You Don't Have To
You've got containers running across Docker, maybe a Swarm cluster, perhaps some Kubernetes pods, and that one Nomad job you set up months ago and forgot about. Keeping track of which images have updates—and which of those updates actually matter—is a chore. WUD (What's Up Docker?) is a lightweight tool that watches your container environments, checks for image updates, and lets you know when something's changed.
What It Does
WUD is a proactive container update monitoring and automation tool. It continuously scans your container environments—whether that's standalone Docker daemons, Docker Swarm, Kubernetes, Docker Compose, or Nomad—and detects when image updates are available across both public and private registries.
The architecture is straightforward. Watchers discover your running containers across whatever orchestrator you're using. The WUD engine then compares versions and digests, pulling information from registries like Docker Hub, GHCR, and private OCI registries. It performs semantic version analysis to figure out what's actually changed. From there, triggers kick in—either notifying you through channels like Discord, Slack, or MQTT, or automatically updating your containers via Compose or other mechanisms.
The whole thing runs as a container itself (the Docker Hub badge suggests you can pull it from getwud/wud), and there's a web dashboard UI for seeing what's going on. Configuration covers registries, triggers, and general settings, all documented on the project's website.
Why It's Cool
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It works across multiple orchestrators. A lot of update tools assume you're all-in on one platform. WUD doesn't care—it'll watch Docker, Swarm, Kubernetes, Compose, and Nomad simultaneously. If you've got a heterogeneous setup (and plenty of us do), that's genuinely useful.
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Semantic version analysis means fewer false alarms. Just knowing a tag changed isn't enough—you want to know if it's a patch, a minor bump, or a major version jump that might break things. WUD does that analysis for you, which makes triage a lot easier.
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Notification channels you probably already use. Discord, Slack, MQTT—these aren't exotic integrations. If you're already piping alerts somewhere, WUD can probably fit into that workflow without much fuss.
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Automatic updates are optional, not mandatory. Some tools want to take over your update process entirely. WUD lets you decide: do you want to be notified and handle it yourself, or do you want it to trigger updates automatically? Both paths are supported.
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Private registries are first-class citizens. Not everyone pulls from Docker Hub. WUD handles private OCI registries, which matters if you're running internal images or using a registry that isn't public.
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The dashboard gives you a quick overview. Instead of parsing logs or checking multiple systems, you get a web UI that shows what's running and what's outdated. Sometimes you just want to glance at something.
How to Try It
The quickest way to get started is to pull the image and run it. Since WUD itself is containerized, you'll want to give it access to your Docker socket (or whatever orchestrator API it needs to watch).
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Head to the repository and check out the Quick Start guide linked in the README.
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Pull the image from Docker Hub:
docker pull getwud/wud -
Configure your watchers and registries. The documentation covers configuration in detail—you'll want to set up which orchestrators to monitor and which registries to check against.
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Set up your triggers. If you want notifications, configure Discord, Slack, or MQTT. If you want automatic updates, configure the Compose trigger or whatever update mechanism fits your setup.
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Run WUD and check the dashboard to see what it finds.
The project has a dedicated documentation site at getwud.app with sections on configuration, triggers, and registries. There's also a contributing guide if you want to get involved, and the issue tracker is the place to go for support.
Final Thoughts
WUD fills a gap that a lot of us have patched together with cron jobs and shell scripts over the years. It's not trying to be a full orchestration platform or a CI/CD system—it's focused on one thing: telling you when your container images have updates and optionally doing something about it. If you're running containers across more than one orchestrator, or if you just want a cleaner way to track image updates than manually checking registries, it's worth a look. The fact that it supports automatic updates but doesn't force them on you is a nice touch—sometimes you want a heads-up, not a surprise deployment.
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