I’m currently setting up Discourse for my community and I’ve encountered a strange issue that isn’t directly related to Discourse itself.
I have a blog, and I want to create a topic for each blog post via the API to enable discussions about the posts. This part works fine. However, the onebox preview for my blog posts isn’t generated:
But: The onebox preview doesn’t work only on my Discourse instance. It works perfectly on other Discourse instances, like here (this isn’t an ad for my blog; it just shows that it generally works):
The blog is a Ghost blog running on my internal Docker host. I’ve already tested a ping
and nslookup
to my blog domain, and even a curl
works fine in the console of the Discourse Docker container.
Now, I want to track down the issue. I’ve studied the Ruby code for Onebox, but since I’m not an expert in Ruby, it’s a bit of a “black box” for me.
I suspect the issue might be related to my internal network and DNS structure. I use AdGuard Home as my primary DNS, and I can see in the DNS logs that external links are correctly resolved, but my internal links aren’t.
I understand this isn’t a Discourse problem, but I need some hints to track this issue down. What would you recommend I double-check?