Clarify the configuration for external TLS termination with NGINX
v0.22, including:
- Instructions to enable the `use-forwarded-headers` option for
ingress in both RKE and RKE2 installations.
- A new section for RKE2 detailing how to create a custom
configuration file for this setting.
- Updates to the required headers section to include
`X-Forwarded-Proto` and `X-Forwarded-Port`.
John Carew
Billy Tat
hridyesh bisht