kube-vip shoud fail if kube_proxy_strict_arp is false in arp mod (#9223)

* fix-kube-vip-strict-arp

* fix-kube-vip-strict-arp

docs/kube-vip.md

@@ -2,6 +2,14 @@
 
 kube-vip provides Kubernetes clusters with a virtual IP and load balancer for both the control plane (for building a highly-available cluster) and Kubernetes Services of type LoadBalancer without relying on any external hardware or software.
 
+## Prerequisites
+
+You have to configure `kube_proxy_strict_arp` when the kube_proxy_mode is `ipvs` and kube-vip ARP is enabled.
+
+```yaml
+kube_proxy_strict_arp: true
+```
+
 ## Install
 
 You have to explicitly enable the kube-vip extension:

inventory/sample/group_vars/k8s_cluster/k8s-cluster.yml

@@ -125,7 +125,7 @@ kube_apiserver_port: 6443  # (https)
 kube_proxy_mode: ipvs
 
 # configure arp_ignore and arp_announce to avoid answering ARP queries from kube-ipvs0 interface
-# must be set to true for MetalLB to work
+# must be set to true for MetalLB, kube-vip(ARP enabled) to work
 kube_proxy_strict_arp: false
 
 # A string slice of values which specify the addresses to use for NodePorts.

roles/kubernetes/control-plane/defaults/main/kube-proxy.yml

@@ -77,7 +77,7 @@ kube_proxy_exclude_cidrs: []
 kube_proxy_scheduler: rr
 
 # configure arp_ignore and arp_announce to avoid answering ARP queries from kube-ipvs0 interface
-# must be set to true for MetalLB to work
+# must be set to true for MetalLB, kube-vip(ARP enabled) to work
 kube_proxy_strict_arp: false
 
 # kube_proxy_tcp_timeout is the timeout value used for idle IPVS TCP sessions.

roles/kubernetes/node/tasks/loadbalancer/kube-vip.yml

@@ -1,4 +1,11 @@
 ---
+- name: kube-vip  | Check cluster settings for kube-vip
+  fail:
+    msg: "kube-vip require kube_proxy_strict_arp = true, see https://github.com/kube-vip/kube-vip/blob/main/docs/kubernetes/arp/index.md"
+  when:
+    - kube_proxy_mode == 'ipvs' and not kube_proxy_strict_arp
+    - kube_vip_arp_enabled
+
 - name: kube-vip | Write static pod
   template:
     src: manifests/kube-vip.manifest.j2