diff --git a/dev_guide/getting_traffic_into_cluster.adoc b/dev_guide/getting_traffic_into_cluster.adoc index a3c3d09acbdb..c5d7731a1271 100644 --- a/dev_guide/getting_traffic_into_cluster.adoc +++ b/dev_guide/getting_traffic_into_cluster.adoc @@ -445,6 +445,25 @@ down, the virtual IP address is automatically transferred to another host in the pool. +[[host-network]] +== Using Host Networking + +You can choose to let the pods use the networking of the host that +they are on rather than containerizing the networking and using +the SDN. This is how the router works, and it can be a useful +technique when you have to proxy a Layer 7 protocol that is not +http/https/or TLS with SNI. You can look at the way the router is +configured to see how to set it up, but basically you need to set +`hostNetwork: true` in the pod definition, and then run the router +with a service account that has the `hostnetwork` permission. You can +grant the permission with `oc adm policy add-scc-to-user hostnetwork +system:serviceaccount:default:someserviceaccountname`. + +Once configured, the pod can access all of the network interfaces on +the node that it is running on, including the host's SDN interface. +This allows you to make your own proxy, or allows you to run a program +directly on the host interfaces directly. + [[ingress-load-balancer]] == Non-Cloud Edge Router Load Balancer