字段选择器是基于字段来筛选资源的，平时用的很少，且支持的字段类型很少，目前仅支持：metadata.name, metadata.namespace, status.phase。操作符支持 =, ==, != 三种。

[root@hdss7-21 ~]# kubectl get pod -A --field-selector metadata.namespace!=app,status.phase=Running
NAMESPACE     NAME                                    READY   STATUS             RESTARTS   AGE
default       nginx-ds-7cs4q                          0/1     ImagePullBackOff   2          7d17h
default       nginx-ds-jdp7q                          0/1     ImagePullBackOff   2          7d17h
kube-system   coredns-6b6c4f9648-nmc9v                1/1     Running            1          18h
kube-system   kubernetes-dashboard-76dcdb4677-z46pd   1/1     Running            3          6d4h
kube-system   traefik-ingress-h5pvj                   1/1     Running            3          6d5h
kube-system   traefik-ingress-vtlch                   1/1     Running            3          6d5h