Good point. I checked the services and some of them are yellow (without error, but stalled in loading). I've restarted one app that uses mongodb and now the backup works. But it's very close to the memory limit. If this happens again, I'll increase the memory assigned.
@nebulon I was having a similar issue with Mongodb since a few days, I backuped the mongodb folder, created a new one, restarted the mongodb service, restarted the apps and the problem is solved 🙂
I am trying to only do this from the Cloudron hosted versions of Metabase/Grafana.
I followed your instructions and this worked perfectly, took the username, password, port, host, and database name from the environment variables within the Wekan web console, entered them in Metabase, and was able to connect and see the data.
Crux of the issue is that the indices name generated are too long. @alex-adestech pointed out to me that this issue only sorted out in MongoDB 4.4 and not even MongoDB 4.2. Searching through the rocket.chat issue tracker I saw only person hit this and nobody replied. Search further, I found that Rocket.Chat doesn't even support MongoDB 4.2. The releases page mentions the versions they test with - https://github.com/RocketChat/Rocket.Chat/releases. This got me wondering why we hit this issue. Well, the answer it turns out is that Cloudron generates 32 byte mongodb database names for apps. This in turn ends up affecting the length of the index.
I have made a fix now for Cloudron 5.6 that generates shorter names. (We have had to do something similar for apps using MySQL as well in the past).