Conteinerized Keycloak behind Nginx reverse proxy requests localhost

Question

Working setup

I have a configuration of

• external VPS with public IP that has Nginx reverse proxy (A)
• internal server with Nginx (B)
• standalone application (not containerized) Keycloak 17.0.1

Which looks like this. I had a domain registrered for that server which is (let's say) auth.example.com

When I go to https://auth.example.com I can see regular keycloak page with link to admin console.

By clicking on the administration console I can properly login to manage master realm.

The problem

As soon as I containerize keycloak all links for administration console and some scripts are no longer working as they are changed from https://auth.example.com to https://localhost

Configs

By containerizing keycloak I did not modify any of the nginx configs.

Nginx A

        location /
        {
                proxy_set_header Host $host;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header X-Forwarded-Host $host;
                proxy_set_header X-Forwarded-Server $host;
                proxy_set_header X-Forwarded-Port $server_port;
                proxy_set_header X-Forwarded-Proto $scheme;
                proxy_pass http://[nginx b ip];
        }

Nginx B

server
{
        server_name auth.example.com;
        location /
        {
            proxy_pass http://localhost:[exposed docker port];
        }
        listen 80;
}

Standalone keycloak (working command)

/usr/bin/bash bin/kc.sh start --proxy edge --hostname=auth.example.com --db-url-host localhost --db-username keycloak --db-password password

Dockerized keycloak (docker-compose)

  keycloak:
    image: quay.io/keycloak/keycloak:latest
    command: start --auto-build --features=token-exchange --hostname-strict-backchannel=true --hostname=auth.example.com
    depends_on:
      - db
    environment:
      KC_METRICS_ENABLED: "true"
      DB_VENDOR: [somedbvendor]
      DB_ADDR: db
      DB_DATABASE: keycloak
      DB_USER: keycloak
      DB_PASSWORD: password
      KEYCLOAK_ADMIN: admin
      KEYCLOAK_ADMIN_PASSWORD: admin
      KC_PROXY: edge
      PROXY_ADDRESS_FORWARDING: "true"
    ports:
      - "8081:8080"
    networks:
      - net

I would like to containerize whole application I have and their dependencies and keycloak is a first step that I cannot complete.