Installing the OMV ImageCheck Plugin: A Beginner’s Guide

This guide installs openmediavault-imagecheck, the small server-side add-on that checks whether your Docker containers have newer images available and reports the count to the OMV Companion app. It never pulls, updates, or changes your containers — it only looks and reports.

You’ll do everything by connecting to your OpenMediaVault (OMV) server’s command line from your own computer and downloading the plugin from GitHub. No coding required — you copy and paste a handful of commands.

• Time needed: about 10 minutes
• Difficulty: beginner (every step is spelled out)
• You will need: your OMV server powered on, the password for it, and any computer (Windows, Mac, or Linux) on the same network

Before you start — a quick checklist

You need three things. Don’t worry, the steps below show you how to get each one.

1. SSH turned on in OMV (Step 1).
2. Your server’s IP address — something like 192.168.1.100 (Step 2).
3. The server’s login — usually the username root and the password you set when you installed OMV.

Your server should already be running Docker with some containers, since that’s what the plugin checks. If Docker isn’t set up yet, do that first.

Step 1 — Turn on SSH in OMV

SSH is usually off by default. Turn it on from the OMV web page:

1. Open OMV in your web browser (the address you normally use to manage it, e.g. http://192.168.1.100) and log in.
2. In the left menu go to Services → SSH.
3. Tick Enabled.
4. Tick Permit root login (this lets you log in as root, which we’ll use below).
5. Click Save, then click the yellow Apply banner that appears at the top.

That’s the only thing you need to do in the web page. Leave the browser open — you’ll use it again at the end to check things worked.

Step 2 — Find your server’s IP address

If you don’t already know it, the OMV web page shows it: go to the OMV Dashboard and look for the network/IP widget, or check Network → Interfaces. Write down the address that looks like 192.168.x.x. We’ll call it YOUR-SERVER-IP from here on.

Step 3 — Open a terminal and connect to the server

A “terminal” is the plain text window where you type commands. Open it based on your computer:

• Windows: click Start, type PowerShell, and open Windows PowerShell.
• Mac: press Cmd+Space, type Terminal, and press Enter.
• Linux: open your Terminal app.

Now connect. Type this (replace YOUR-SERVER-IP with the address from Step 2) and press Enter:

ssh root@YOUR-SERVER-IP

Example: ssh root@192.168.1.100

• The first time you connect, it asks something like “Are you sure you want to continue connecting (yes/no)?” — type yes and press Enter. (This is normal; it’s just remembering your server.)
• It then asks for a password. Type your OMV root password and press Enter. Note: the password is invisible as you type — no dots or stars appear. That’s normal. Just type it and press Enter.

When you see the prompt change to something ending in # (for example root@omv:~#), you’re connected to the server. Everything you type now runs on the server.

Step 4 — Make sure git is installed

git is the tool that downloads code from GitHub. Most systems have it; this installs it if it’s missing. Copy-paste the whole line and press Enter:

apt-get update && apt-get install -y git

If it was already installed, this just finishes quickly. If it installs it, that’s fine too.

Step 5 — Download the plugin from GitHub

This copies the plugin’s files onto your server. Paste and press Enter:

git clone https://github.com/hackitz/openmediavault-imagecheck.git

You’ll see a few lines about “Cloning into…” and it finishes in a second or two. Now move into the folder it created:

cd openmediavault-imagecheck

Step 6 — Run the installer

This puts the plugin into place, does a first check to warm up the data, and restarts the OMV engine so the app can talk to it. Paste and press Enter:

sudo bash install.sh

(You’re logged in as root, so it won’t ask for a password again.) Let it finish — it prints its progress and ends when it’s done. This can take a minute the first time because it checks each of your containers’ images.

Step 7 — Check that it worked

Run the plugin’s own status command:

omv-imagecheck --print

You should see some output listing your containers and how many have updates available (for example a line with "updateCount"). If you see that, the plugin is installed and working. 🎉

You can also confirm the app-facing service responds:

omv-rpc -u admin 'ImageCheck' 'getStatus'

That prints a short summary the OMV Companion app reads.

When you’re done, you can close the connection by typing exit and pressing Enter.

What happens now

• The plugin checks your images once a day automatically (early morning) and saves the result. It doesn’t hammer your network or Docker Hub.
• The OMV Companion app reads that saved result and shows the “updates available” count next to your other server info — no extra setup in the app.
• It only reports. It never pulls or changes a container. You stay in control of when to actually update anything.

Updating the plugin later

If a newer version of the plugin is released on GitHub, connect again (Step 3) and run:

cd openmediavault-imagecheck
git pull
sudo bash install.sh

git pull grabs the latest files; re-running the installer applies them.

Uninstalling

If you ever want to remove it, connect again and run:

cd openmediavault-imagecheck
sudo bash uninstall.sh

Troubleshooting

“Connection refused” or “Connection timed out” when you run ssh
SSH probably isn’t enabled yet, or the IP is wrong. Recheck Step 1 (and that you clicked Apply) and Step 2. Make sure your computer is on the same network as the server.

“Permission denied” after typing your password
The password was mistyped (remember, it’s invisible as you type — that’s normal), or root login isn’t allowed. Recheck the Permit root login box in Step 1, and try again. If you normally use a different username, log in with ssh yourname@YOUR-SERVER-IP instead, and put the word sudo in front of the install/uninstall commands.

git: command not found
Run Step 4 again to install it: apt-get update && apt-get install -y git.

fatal: repository not found when cloning
Double-check the web address in Step 5 is typed exactly. The repository must be public and pushed to GitHub first — if you just created it, make sure it finished uploading.

The installer complains about docker or docker buildx
The plugin needs Docker to be installed and reachable as root, and it uses docker buildx (which comes with modern Docker). If Docker isn’t set up on this server yet, set that up first, then re-run sudo bash install.sh.

omv-imagecheck --print shows errors on some containers
That’s usually fine. Containers built locally or pinned to an exact digest have nothing to compare against, and a private registry needs the host to be logged in (docker login). Those show as per-item notes and are not counted as false “updates.”

Optional (advanced): download using GitHub over SSH

You don’t need this — the public HTTPS download in Step 5 is simpler and works for everyone. Use this only if you already have SSH keys set up with your GitHub account. In that case, replace the Step 5 clone command with:

git clone git@github.com:hackitz/openmediavault-imagecheck.git

Everything else in the guide is exactly the same.