SSO HTTP Authentication

Here are some different ways. Note using module and then passing HTTP Header values/cookies to backend is usually the easiest. You can write your own LUA integration too.

https://developers.shopware.com/blog/2015/03/02/sso-with-nginx-authrequest-module/

https://github.com/nginx-shib/nginx-http-shibboleth

https://www.haproxy.com/blog/haproxy-enterprise-offers-saml-based-single-sign-on/

https://techdocs.f5.com/en-us/bigip-14-1-0/big-ip-access-policy-manager-saml-configuration-14-1-0/introducing-access-policy-manager-saml-support.html#GUID-28F26377-6E10-42C9-883A-3AC65EAB9092