OH3 where is the log viewer (with docker Container on Synology)

I now have a well running OH3 container on my Synology NAS (here’s my way). During the installation, I was a bit quick and unconcentrated in not paying attention to the port settings - in other words, my container looks like this:


So i’ve no idea where the logviewer (which i know from oh2) is … on my old raspy-oh2.5 it was found in Port 9001:

Can anyone help?
Thanks in advantage

openHAB has never contained a log viewer.

openHABian (the easy system for the Raspberry Pi) has the option to install the frontail log viewer but that is a separate application. Some people have configured frontail to work with OH3.

oh, o.k. … you never stop learning …
the log-viewer or any log is sure very helpful … is there a “cookbook” how to get a log running in an “OH3-on-Docker (running on Synology)” environment?

There is a docker image available for frontail which is the software used for the log viewer in openhabian.

You have to mount the log directory from your oh container into the frontail container to give frontail access to the logs.

I have this running on Synology for years without any issues.

Maybe I can share my docker compose later when I’m back home


thanks for your offer, Sebastian.
At the moment I just found a smaller, simple solution with the Developer Sidebar - maybe interesting for some of you:


That would be useful for troubleshooting.

@ysc A good enhancement to that might be a way to set DEBUG logging for some bundles ( for a certain period of time?) Hey. If I dream I might as well dream big LOL.

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There’s no API for it, and I doubt it’s on the roadmap, but-
You might or might know it, and I don’t know if it’s safe to tell, but you can easily install the Karaf web console with:

feature:install webconsole

Then if you go to http://instance:8080/system/console (the user/pwd is the same as SSH) ou have a lot of geeky management options, I wouldn’t be surprised if you found an option to change the log level there.
There’s even a terminal emulator (in the Main > Gogo menu I think) to type your commands.
Obviously it’s way less safe than SSH but if you want to take the risk…


Not that much different if you use https & authentication / authorization :wink:

Yes but I doubt many will bother changing the default password, and as opposed to SSH this listens on all interfaces, not only localhost.

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Sadly that is not complete. It’s a perfect replacement for watching events.log but most of the really interesting bits are in openhab.log.

I wonder what it will do if you have the console to only allow certificate authentication.

If it’s the full console (IIRC it is) you can do anything through the web console that can be done in the main console which includes tailing and changing the logging level.

Ah, Thanks - this helps much! I’ve found the openhab.log and events.log easily by File Station …
what confuses me are the other files in the folder … if I understand it correctly, a new log file is started when the old one exceeds .16mb. … so i could remove the .log.1 - log.7, couldn’t i?

Then something else I don’t understand: in all logs are timestamps of (my) things from the beginning of the year - but I installed Openhab for the first time on Synology via docker just last month…(?).

You can remove the other files but anything beyond the 10th file gets deleted automatically anyway.

You probably are reusing the same folders as was used for OH 2 so OH 3 is just continuing the log.

In OH2 frontail was offered my means of a link in the homepage, is it possibile in MainUI ? (I am talking about Openhabian setup where frontail is already there)
I also see that frontail is Node.js as MainUI, is maybe possibile to integrate the 2 ?
I would be super and help users a lot (and thus devs life) to provide feedbacks if a log is integrated in MainUI, possibly with option to set DEBUG loglevel for a specific binding

Frontail works by directly accessing the log files. MainUI works by interacting with the openHAB REST API,. The logs are not exposed through the REST API so MainUI does not have access to them.

Installing Frontail or the webconsole yourself is certainly an option. Also, there are lots of people asking for it, but has anyone gone to the openhab-core repo and opened a feature request?

the link solution (as in OH2): is it an issue for openhab-core, openhab-distro or more probably for openhab-webui ?

openhab-core needs to implement a REST API to expose the logs. Once that is implemented the webui’s can use that REST API to show you the logs. If you just want a link to the logs as served up by Frontail, I believe M5 has the ability to put a webview onto a Page now. You can put Frontail into a widget on a Page.

I don’t know if there is a way to add to the list of applications in the upper right hand corner menus where BasicUI and HABPanel are listed.

There is a way to add to the left menu though that was shown at the meeting. I just do not know the mechanism behind that.

For that you just need to create a new Page.

From “settings -> Pages” click on the + icon and select Layout (or one of the other page types you might want to create).

Give it an ID and a nice Name, open up the “Sidebar and Visibility” and toggle on “Show on Sidebar”.

From there I don’t know what to say. I’m not even certain that the webview widget has been merged into the baseline yet. I remember seeing the PR scroll by my feed but that’s about it. I don’t have a need for a Webview so I didn’t look any closer.

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In response to the OP, @welteki has created a docker image that even has the OpenHab theme! You can find it on Docker hub - ’ welteki/frontail-openhab’. I have created a docker-compose file, which I run from an SSH shell on my Synology NAS. You will need to change the file path to match your Synology setup. Note: Also change the file extension to ‘yml’
docker-compose.txt (265 Bytes)

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@ysc openHAB is using Karaf. Karaf is using PAX-LOGGING.
It is pretty easy to add self-written log appender to PAX-LOGGING.
I have written some time already an appender that inspect the log messages and send mails if a log message contains an exception.
We could think about an appender that writes all log messages using SSE.
A SSE client could use a filter expression to get only informed about a specific log level (similar as the filters for the SSE that published the event stream).
The SSE resource itself could be “admin only” or we consider if an admin enabled the appender he knows it will be not secured.