How to set hostNetwork:true for k8s 1.21 and up

[mrolmedo]

Summary:
In K8s 1.21 and up, the ingress controller no longer runs in hostnetwork:true. The docs for RKE and [Rancher] outlines that. Based on #378, and (rancher/rancher#35943 (comment)), IMHO, the docs should include the steps on how to set up or how to modify this parameter in Rancher Custom cluster or clusters launched with rke up. I´d also include more details about the tcp udp services impacted. For instance, For Kubernetes v1.21 and up, all services exposed via TCP or UDP, set up in ConfigMap tcp-services or udp-services in the ingres-nginx namespace, will stop working if the hostnetwork:true is not set.
Thanks for your attention.

SURE-6006

[martyav]

@snasovich would you be able to assist with instructions on how to set hostNetwork:true for k8s 1.21 and up (or ping somebody who can)?

[snasovich]

@martyav , hopefully @kinarashah can help with this.

[kinarashah]

@martyav HostNetwork can be configured by setting network options in the cluster.yml https://rke.docs.rancher.com/config-options/add-ons/ingress-controllers#configuring-network-options

ingress:
  provider: nginx
  network_mode: hostNetwork
  // other fields

[martyav]

@kinarashah is there a way to do this through the Rancher UI, or do you have to edit the cluster yaml?

[martyav]

@kinarashah Just following up with the last question. See above. Thank you!

[kinarashah]

@martyav Apologies for missing the earlier ping, we do not expose this field in UI so it'll have to be via Edit as Yaml option. There are only few things that can be changed in UI for ingress, like enabling/disabling nginx ingress and default backend.