I have two AKS K8s clusters (ver 1.11.1 in West and North Europe) with http-application-routing addon enabled. Suddenly today pod named addon-http-application-routing-nginx-ingress-controller-xxxx crashed and showed the state:

  State:        Waiting
  Reason:       CrashLoopBackOff
  Last State:   Terminated
  Reason:       Error
  Exit Code:    255

kubectl logs addon-http-application-routing-nginx-ingress-controller-xxxx shows:

I1003 20:21:21.129694       7 flags.go:162] Watching for ingress class: addon-http-application-routing
W1003 20:21:21.129745       7 flags.go:165] only Ingress with class "addon-http-application-routing" will be processed by this ingress controller
F1003 20:21:21.129819       7 main.go:59] Port 80 is already in use. Please check the flag --http-port

If I connect to any node on any cluster and check opened ports with netstat -latun it shows no service on 80 port. Node restart didn't help.