GitLab OAuth Issues

I have configured GitLab authentication with a brand new Taiga instance. The instance itself comes up just fine, but when I click to register with GitLab, and it goes to GitLab successfully, I get redirected back to Taiga (expected) and get this (unexpected):

Oops, something went wrong…
Our Oompa Loompas have not been able to get you credentials from GitLab.

Consulting with the browser console, I’m getting this:

[HTTP/1.1 400 Bad Request 398ms]


Worth mentioning, I’m able to use my GitLab instance to authenticate a few other apps over OAuth2. However, oddly, I’ve been having a similar inexplicable failure at this same step with Mattermost…it may be unrelated, or it may not.

Hi @CodeMouse92

Apparently, the functionality works perfectly (tested on Can you check the logs to see if there is any more information about the error?

Best regards

I have posted everything I know to look for. Is there another location I should be checking? (Finding the logs is not straightforward here.)

Well. How did you install Taiga: with docker or directly from source code?

From Docker. I’ve checked the few logs I know about, butnn9thing is evident.

There is no log messages related to github auth at docker compose logs taiga-back? You can check logs messages from your gitlab instance too, maybe you can find something.

Without logs it is very difficult to know what might be happening. I have tested the functionality against gitlab SaaS and against an on premise instance and it works perfectly. Maybe there is something misconfigured in gitlab that prevents authentication to third party applications?

There is actually nothing in the logs for taiga-back. As for GitLab configuration per se being the problem, that’s not really possible, I’m currently using that GitLab instance as the OAuth2 provider for Nextcloud and Discourse, successfully. There is only one other app having problems with authenticating, so either something is subtly wrong in GitLab (outside of configuration), or there are parallel but separate bugs in Mattermost and Taiga. (Incidentally, now I’m curious if they share an OAuth2 dependency.)

However, just in case it is misconfiguration, would you be able/willing to test OAuth2 authentication against my (publicly accessible) GitLab? I can provide the test account credentials and the OAuth2 configuration details via DM if you’re willing. If it works, we know the problem is my Taiga instance; if not, it’s probably the GitLab (even though it authenticates for other things).