Git client requests forwarded to backend

[secinto]

Hi,

I have the situation that several gitlab instances are hosted behind the gatekeeper. The OpenID authentication using gatekeeper and keycloak and forwarding it then to gitlab, where the authentication from M365 is relayed already works. The issue now is that a git client which wants to clone (or perform any other operation) a repo has (obviously) the issue that no authentication is present and doesn't know how to handle the redirect to keycloak.

git clone https://app.example.com/gitlab/user/IOT-Test.git
fatal: unable to update url base from redirection:
asked for: https://app.example.com/gitlab/user/IOT-Test.git/info/refs?service=git-upload-pack
redirect: https://idp.example.com/realms/auth-proxy/protocol/openid-connect/auth?access_type=online&client_id=auth-proxy-gatekeeper-client&code_challenge=XzDiFqMQ1XB8Nu5ZfOu34fNCAf-V71Lvu9nnM8oSEVY&code_challenge_method=S256&redirect_uri=https%3A%2F%2Fapp.example.com%2Foauth%2Fcallback&response_type=code&scope=email+profile+openid&state=9e07d0e2-241d-43c4-95e7-c15511c78ec1

Has someone already done something like that?

Best regards,
Stefan