Inability to generate link previews, serious bug


Didn’t find where it was previously discussed, but on this forum for some time the Onebox functionality of Discourse no longer works and this means when dropping in a link to some external website we do not get a nice preview generated from OpenGraph metadata on that page.

I recently spun up a Discourse forum myself using Yunohost at and just now observed that I have the exact same problem.

Nowhere in the logs (at least the ones available in the UI’s) of both Yunohost or Discourse can I find any error relating to this problem. Also, since I installed the forum I haven’t updated anything, and I don’t see anything about an auto-update. And Onebox used to work on the fresh install. It is a mystery why now it doesn’t.

So I expect there’s more nasty deep digging to be done to find and solve this problem, and that likely we face a Yunohost-related issue. Personally I find the generation of those oneboxes very useful and would hate it if I didn’t get it to work. On the whole I am not really satisfied how Yunohost has disabled the native update functionality in Discourse.

I’ll keep you posted if I find anything more related to this problem.

I filed an issue on Github in the Yunohost-Discourse repository:

Onebox link preview generation suddenly stops working #108

I posted to Yunohost forum the suggestion to have the option to leave upgrade to the app (Discourse in our case) if the app has a good upgrade UX from itself. See: Ability to skip Yunohost update process and leave it to the App - Discuss - YunoHost Forum

Update: I also created a feature request on the Issue tracker:

I thought there were no error logs, but I was wrong and just updated that to the Github issue:

And I just verified that the same error also occurs on this forum.

Update: There is a related issue where fetching images from an external URL to store locally also results in failure. I have updated the Github issue. Testing if the issue also occurs here (this depends on a forum admin setting to cache images locally) → Nope… not witnessed here.