I wanted to disable the admin user in Argo, primarily because I wanted to have all logins go through my OIDC provider.

With ArgoCD you have the ability to use local users, external users (via OIDC) or both.

I wanted to force all logins through the OIDC provider and remove the username/password text boxes from the login screen.

To do this, modify the argocd-cm config map and add a new entry, admin.enabled. Set it to false and apply it.

Below is the relevant parts of the config map.

apiVersion: v1
kind: ConfigMap
  name: argocd-cm
  admin.enabled: "false"

After applying the configuration map on the login screen, leave only the button to log in through the SSO provider.