老师，部署ingress-nginx时候，用的是您的madatory.yaml文件，运行后nginx-ingress-controller处于CrashLoopBackOff状态，describe后的结果是

Events:
Type Reason Age From Message

Normal Scheduled 39m default-scheduler Successfully assigned ingress-nginx/nginx-ingress-controller-65ccbbc7bb-x5tnd to syq-g05-64.41-jiagou.cn
Normal Pulled 37m (x5 over 39m) kubelet, syq-g05-64.41-jiagou.cn Container image “quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.19.0” already present on machine
Normal Created 37m (x5 over 39m) kubelet, syq-g05-64.41-jiagou.cn Created container nginx-ingress-controller
Normal Started 37m (x5 over 39m) kubelet, syq-g05-64.41-jiagou.cn Started container nginx-ingress-controller
Warning BackOff 4m29s (x166 over 39m) kubelet, syq-g05-64.41-jiagou.cn Back-off restarting failed container

请问这是什么原因