I'm trying to enable OIDC federation in the horizon-operator by using the customServiceConfig options but these changes do not seem to be used by the dashboard:

oc get cm horizon-config-data -o jsonpath={.data} | jq '."9999_custom_settings.py"'
"WEBSSO_ENABLED = True\nWEBSSO_INITIAL_CHOICE = \"OIDC\"\n\nWEBSSO_CHOICES = (\n  (\"credentials\", _(\"Keystone Credentials\")),\n  (\"OIDC\", _(\"OpenID Connect\")),\n)\n\nWEBSSO_IDP_MAPPING = {\n  \"OIDC\": (\"kcipaIDP\", \"openid\"),\n}\n"

oc exec horizon-64cd548c4d-5v9z4 – cat /etc/openstack-dashboard/local_settings.d/9999_custom_settings.py
WEBSSO_ENABLED = True
WEBSSO_INITIAL_CHOICE = "OIDC"

WEBSSO_CHOICES = (
  ("credentials", _("Keystone Credentials")),
  ("OIDC", _("OpenID Connect")),
)

WEBSSO_IDP_MAPPING = {
  "OIDC": ("kcipaIDP", "openid"),
}

The addition of this block should add the OIDC option to the Horizon login page but it does not.  I have verified, by using a custom horizon-operator image, that modifying the local_settings template with these values does add the OIDC option to the login page.

Please let me know if you need more information, or an environment to test on.

Thanks,

/Dave