Bad Gateway at the end of OIDC flow with Microsoft Entra and no Dex

[NiklasRosenstein]

I'm trying to enable Microsoft Entra as SSO for our ArgoCD instance installed from the Helm chart (v7.7.6) using OIDC (not SAML). I've followed the guide here: https://argo-cd.readthedocs.io/en/stable/operator-manual/user-management/microsoft/#entra-id-app-registration-auth-using-oidc

The relevant Helm values I use are:

    dex:
      enabled: false
    configs:
      cm:
        url: https://{{ .Values.ingress.host }}/
        oidc.config: |
          name: AzureAD
          issuer: '{{ required ".oidc.issuer missing" .Values.oidc.issuer }}'
          clientID: '{{ required ".oidc.clientID missing" .Values.oidc.clientID }}'
          clientSecret: $oidc.azure.clientSecret
          requestedIDTokenClaims:
            groups:
              essential: true
              value: "SecurityGroup"
          requestedScopes:
          - openid
          - profile
          - email
      secret:
        extra:
          oidc.azure.clientSecret: '{{ required ".oidc.clientSecret missing" .Values.oidc.clientSecret }}'

When I log in via SSO in ArgoCD, I get directed through Entra and back to ArgoCD, but then the Ingress returns a 502 😕 We're using ingress-nginx

From the argocd-server logs, it seems the login succeeds:

The ingress-nginx logs are not much more helpful:

Any idea what's going on? Thank you!

Edit: I get the same behavior on ArgoCD 2.12.4 (Helm Chart 7.6.10).