kubectl 常用命令

kubectl get cs

[root@master ~]# kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-0               Healthy   {"health":"true"}   

kubectl get deploymen

kubectl get pods --all-namespaces

[root@master ~]# kubectl get pods --all-namespaces
NAMESPACE     NAME                             READY   STATUS    RESTARTS   AGE
kube-system   coredns-f9fd979d6-8bqmr          0/1     Pending   0          75m
kube-system   coredns-f9fd979d6-9hgs9          0/1     Pending   0          75m
kube-system   etcd-master                      1/1     Running   3          75m
kube-system   kube-apiserver-master            1/1     Running   3          75m
kube-system   kube-controller-manager-master   1/1     Running   0          30m
kube-system   kube-proxy-7k5wr                 1/1     Running   0          75m
kube-system   kube-proxy-9m8jq                 1/1     Running   0          72m
kube-system   kube-proxy-bjhk9                 1/1     Running   2          75m
kube-system   kube-scheduler-master            1/1     Running   0          31m
ns-elastic    elasticsearch-data-0             0/1     Pending   0          65m
ns-elastic    elasticsearch-master-0           0/1     Pending   0          65m

kubectl delete pods elasticsearch-data-0

kubectl get namespace kube-system -o yaml

只查看kube-system的名称空间信息并以yaml格式显式

[root@master ~]# kubectl get namespace kube-system -o yaml 
apiVersion: v1
kind: Namespace
metadata:
  creationTimestamp: "2020-10-01T22:32:28Z"
  managedFields:
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:status:
        f:phase: {}
    manager: kube-apiserver
    operation: Update
    time: "2020-10-01T22:32:28Z"
  name: kube-system
  resourceVersion: "4"
  selfLink: /api/v1/namespaces/kube-system
  uid: 58592158-9fcd-41f7-9305-c79ee1161468
spec:
  finalizers:
  - kubernetes
status:
  phase: Active

只查看kube-system的名称空间信息并以json格式显式

[root@master ~]# kubectl get namespace kube-system -o json 
{
    "apiVersion": "v1",
    "kind": "Namespace",
    "metadata": {
        "creationTimestamp": "2020-10-01T22:32:28Z",
        "managedFields": [
            {
                "apiVersion": "v1",
                "fieldsType": "FieldsV1",
                "fieldsV1": {
                    "f:status": {
                        "f:phase": {}
                    }
                },
                "manager": "kube-apiserver",
                "operation": "Update",
                "time": "2020-10-01T22:32:28Z"
            }
        ],
        "name": "kube-system",
        "resourceVersion": "4",
        "selfLink": "/api/v1/namespaces/kube-system",
        "uid": "58592158-9fcd-41f7-9305-c79ee1161468"
    },
    "spec": {
        "finalizers": [
            "kubernetes"
        ]
    },
    "status": {
        "phase": "Active"
    }
}

查看指定名称空间的pod(在k8s中容器被封装成pod)

[root@master ~]# kubectl get pods --all-namespaces
NAMESPACE     NAME                             READY   STATUS    RESTARTS   AGE
kube-system   coredns-f9fd979d6-8bqmr          0/1     Pending   0          87m
kube-system   coredns-f9fd979d6-9hgs9          0/1     Pending   0          87m
kube-system   etcd-master                      1/1     Running   3          87m
kube-system   kube-apiserver-master            1/1     Running   3          87m
kube-system   kube-controller-manager-master   1/1     Running   0          41m
kube-system   kube-proxy-7k5wr                 1/1     Running   0          86m
kube-system   kube-proxy-9m8jq                 1/1     Running   0          84m
kube-system   kube-proxy-bjhk9                 1/1     Running   2          87m
kube-system   kube-scheduler-master            1/1     Running   0          42m
ns-elastic    elasticsearch-data-0             0/1     Pending   0          77m
ns-elastic    elasticsearch-master-0           0/1     Pending   0          77m
[root@master ~]# kubectl get pods -n ns-elastic
NAME                     READY   STATUS    RESTARTS   AGE
elasticsearch-data-0     0/1     Pending   0          77m
elasticsearch-master-0   0/1     Pending   0          77m
[root@master ~]# 

查看当前集群的deployments控制器

[root@master ~]# kubectl get deploy -n kube-system -o wide
NAME      READY   UP-TO-DATE   AVAILABLE   AGE    CONTAINERS   IMAGES                     SELECTOR
coredns   0/2     2            0           100m   coredns      k8s.gcr.io/coredns:1.7.0   k8s-app=kube-dns

查看名称空间，namespace简写形式

[root@master ~]# kubectl get ns 
NAME              STATUS   AGE
default           Active   101m
kube-node-lease   Active   101m
kube-public       Active   101m
kube-system       Active   101m
ns-elastic        Active   94m

删除资源

删除名称为"ns-elastic"名称空间,如果想要删除多个名称空间使用空格隔开即可，删除资源时会删除该名称空间下的所有pods资源,因此删除名称空间是很危险的操作，生产环境要谨慎操作

[root@master ~]# kubectl get ns 
NAME              STATUS   AGE
default           Active   104m
kube-node-lease   Active   104m
kube-public       Active   104m
kube-system       Active   104m
ns-elastic        Active   97m
[root@master ~]# kubectl delete ns ns-elastic
namespace "ns-elastic" deleted
[root@master ~]# kubectl get ns 
NAME              STATUS   AGE
default           Active   105m
kube-node-lease   Active   105m
kube-public       Active   105m
kube-system       Active   105m