k8s 标签

一、标签是k8s特色的管理方式，便于分类管理资源对象。一个标签可以对应多个资源，一个资源也可以有多个标签，它们是多对多的关系。 一个资源拥有多个标签，可以实现不同维度的管理。

1.查看标签

[root@k8s-master1 demo]# kubectl get pods --show-labels
NAME                                      READY   STATUS    RESTARTS   AGE   LABELS
centos-78656cf799-g5zl7                   1/1     Running   3          39h   pod-template-hash=78656cf799,run=centos
jenkins-0                                 0/1     Running   3          39h   controller-revision-hash=jenkins-5969f94b88,name=jenkins,statefulset.kubernetes.io/pod-name=jenkins-0
nfs-client-provisioner-6998d9d457-jdmdf   1/1     Running   4          40h   app=nfs-client-provisioner,pod-template-hash=6998d9d457
[root@k8s-master1 demo]# kubectl  get node --show-labels
NAME            STATUS   ROLES    AGE   VERSION   LABELS
192.168.1.112   Ready    <none>   13d   v1.12.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/hostname=192.168.1.112
192.168.1.113   Ready    <none>   13d   v1.12.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/hostname=192.168.1.113

 2.过滤标签

[root@k8s-master1 demo]# kubectl get pods -l app
NAME                                      READY   STATUS    RESTARTS   AGE
nfs-client-provisioner-6998d9d457-jdmdf   1/1     Running   4          40h
[root@k8s-master1 demo]# kubectl get pods -L app
NAME                                      READY   STATUS    RESTARTS   AGE   APP
centos-78656cf799-g5zl7                   1/1     Running   3          39h   
jenkins-0                                 0/1     Running   3          39h   
nfs-client-provisioner-6998d9d457-jdmdf   1/1     Running   4          40h   nfs-client-provisioner

 3.增加标签，修改标签

[root@k8s-master1 demo]# kubectl label pod  jenkins-0  app=jenkins-0 --overwrite
pod/jenkins-0 labeled
[root@k8s-master1 demo]# kubectl get pods -L app
NAME                                      READY   STATUS    RESTARTS   AGE   APP
centos-78656cf799-g5zl7                   1/1     Running   3          39h   
jenkins-0                                 0/1     Running   3          39h   jenkins-0
nfs-client-provisioner-6998d9d457-jdmdf   1/1     Running   4          40h   nfs-client-provisioner