Kubectl 速查表

Node

查看 Node 资源使用情况

$ kubectl top node
NAME                    CPU(cores)   CPU%        MEMORY(bytes)   MEMORY%
172.16.192.36           1961m        12%         16885Mi         61%
172.16.193.199          839m         5%          8046Mi          27%
172.16.193.75           1915m        12%         10597Mi         38%

获取指定 Node 上的 pod 列表

$ kubectl get po -A -o wide --field-selector spec.nodeName=172.16.192.36
NAMESPACE     NAME                   READY    STATUS    RESTARTS   AGE     IP               NODE            NOMINATED NODE   READINESS GATES
kube-system   kube-proxy-6gbzq       1/1      Running   0          13d     172.16.192.36    172.16.192.36   <none>           <none>
kube-system   node-local-dns-tqpkz   1/1      Running   0          2d7h    172.16.192.36    172.16.192.36   <none>           <none>
kube-system   kube-proxy-6gbzq       1/1      Running   0          13d     172.16.192.36    172.16.192.36   <none>           <none>

获取节点总可用资源

$ kubectl get node -o=custom-columns="NODE:.metadata.name,ALLOCATABLE CPU:.status.allocatable.cpu,ALLOCATABLE MEMORY:.status.allocatable.memory"
NODE                    ALLOCATABLE CPU   ALLOCATABLE MEMORY
172.16.192.36           15600m            28262728Ki
172.16.193.199          15890m            30121540Ki
172.16.193.75           15600m            28262728Ki

节点更新维护

# 1. 标记节点不可被调度
$ kubectl cordon 172.16.192.36
 
# 2.驱逐节点上的所有 pod（除 daemonset），并删除临时盘
$ kubectl drain 172.16.192.36 --ignore-daemonsets --delete-emptydir-data
 
# 3. 重新标记节点为可调度
$ kubectl uncordon 172.16.192.36

Pod

设置 Pod 调度策略

硬亲和（requiredDuringSchedulingIngoredExecution）：

affinity:
  nodeAffinity:
    requiredDuringSchedulingIgnoredDuringExecution:
      nodeSelectorTerms:
      - matchExpressions:
          - key: foo
            operator: In
            values:
            - bar

软亲和（preferredDuringSchedulingIgnoredExecution）：

nodeAffinity:
  preferredDuringSchedulingIgnoredDuringExecution:
  - preference:
      matchExpressions:
      - key: foo
        operator: In
        values:
        - ""
    weight: 100