12. kubernetes调度——污点Taint和容忍Toleration

一、通过节点属性调度

1、节点名称

[root@k8s-master ~]# kubectl get nodes
NAME                   STATUS   ROLES           AGE    VERSION
k8s-master.linux.com   Ready    control-plane   127d   v1.29.1
k8s-node01.linux.com   Ready    <none>          127d   v1.29.1
k8s-node02.linux.com   Ready    <none>          127d   v1.29.1

apiVersion: apps/v1
kind: Deployment
metadata:name: test1
spec:replicas: 2selector:matchLabels:app: test1template:metadata:labels:app: test1spec:nodeName: k8s-node02.linux.com					// 指定工作节点名称containers:- name: test1image: centos:7imagePullPolicy: IfNotPresentcommand:- sleep- "3600"

[root@k8s-master schedulerTest]# kubectl create -f test1.yaml 
deployment.apps/test1 created
[root@k8s-master schedulerTest]# 
[root@k8s-master schedulerTest]# kubectl get pod -o wide
NAME                         READY   STATUS                   RESTARTS   AGE   IP              NODE                   NOMINATED NODE   READINESS GATES
test1-d69854cd5-jgpvm        1/1     Running                  0          7s    10.88.242.139   k8s-node02.linux.com   <none>           <none>
test1-d69854cd5-tzx6l        1/1     Running                  0          7s    10.88.242.138   k8s-node02.linux.com   <none>           <none>

2、节点标签

2.1 查看节点标签

[root@k8s-master schedulerTest]# kubectl get nodes --show-labels 
NAME                   STATUS   ROLES           AGE    VERSION   LABELS
k8s-master.linux.com   Ready    control-plane   127d   v1.29.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-master.linux.com,kubernetes.io/os=linux,node-role.kubernetes.io/control-plane=,node.kubernetes.io/exclude-from-external-load-balancers=
k8s-node01.linux.com   Ready    <none>          127d   v1.29.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node01.linux.com,kubernetes.io/os=linux
k8s-node02.linux.com   Ready    <none>          127d   v1.29.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node02.linux.com,kubernetes.io/os=linux

2.2 添加标签

[root@k8s-master schedulerTest]# kubectl label node k8s-node01.linux.com disk=ssd 
node/k8s-node01.linux.com labeled

[root@k8s-master schedulerTest]# kubectl get nodes --show-labels
NAME                   STATUS   ROLES           AGE    VERSION   LABELS
k8s-master.linux.com   Ready    control-plane   127d   v1.29.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-master.linux.com,kubernetes.io/os=linux,node-role.kubernetes.io/control-plane=,node.kubernetes.io/exclude-from-external-load-balancers=
k8s-node01.linux.com   Ready    <none>          127d   v1.29.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,disk=ssd,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node01.linux.com,kubernetes.io/os=linux
k8s-node02.linux.com   Ready    <none>          127d   v1.29.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node02.linux.com,kubernetes.io/os=linux

2.3 修改标签

[root@k8s-master schedulerTest]# kubectl label node k8s-node01.linux.com disk=full --overwrite 
node/k8s-node01.linux.com labeled

[root@k8s-master schedulerTest]# kubectl get node --show-labels
NAME                   STATUS   ROLES           AGE    VERSION   LABELS
k8s-master.linux.com   Ready    control-plane   127d   v1.29.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-master.linux.com,kubernetes.io/os=linux,node-role.kubernetes.io/control-plane=,node.kubernetes.io/exclude-from-external-load-balancers=
k8s-node01.linux.com   Ready    <none>          127d   v1.29.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,disk=full,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node01.linux.com,kubernetes.io/os=linux
k8s-node02.linux.com   Ready    <none>          127d   v1.29.1   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node02.linux.com,kubernetes.io/os=linux
[root@k8s-master schedulerTest]# 

2.4 删除标签

[root@k8s-master schedulerTest]# kubectl label node k8s-node01.linux.com disk-
node/k8s-node01.linux.com unlabeled

2.5 通过节点标签进行调度

apiVersion: apps/v1
kind: Deployment
metadata:name: test2
spec:replicas: 2selector:matchLabels:app: test2template:metadata:labels:app: test2spec:nodeSelector:								// 节点标签 ram: highercontainers:- name: test2image: centos:7imagePullPolicy: IfNotPresentcommand:- sleep- "3600"

二、污点Taint和容忍Toleration

污点、容忍配合使用，避免pod被分配不合适的机器

1、污点Taint

污点，本质上就是个key-value

1.1 查看Master节点的污点

[root@k8s-master schedulerTest]# kubectl describe node k8s-master.linux.com | grep -i taint
Taints:             node-role.kubernetes.io/control-plane:NoSchedule

1.2 添加污点

格式：# kubectl taint node <节点名称> key=value:{NoSchedule|NoExecute|PreferNoSchedule}

污点策略:

• NoSchedule
  新建的POD不会再向该节点调度
  已经运行在该节点的POD不会受影响

• NoExecute
  新建的POD不会再向该节点调度
  已经运行在该节点的POD同时也会被驱逐

• PreferNoSchedule
  尽量不向该节点调度新建的POD

[root@k8s-master schedulerTest]# kubectl taint node k8s-node02.linux.com fan=error:NoExecute 
node/k8s-node02.linux.com tainted[root@k8s-master schedulerTest]# kubectl describe node k8s-node02.linux.com | grep -i taint
Taints:             fan=error:NoExecute

1.3 删除污点

格式：# kubectl taint node <节点名称> key:{NoSchedule|NoExecute|PreferNoSchedule}-

2、容忍Toleration

apiVersion: apps/v1
kind: Deployment
metadata:name: test5
spec:replicas: 2selector:matchLabels:app: test5template:metadata:labels:app: test5spec:containers:- name: test5image: centos:7imagePullPolicy: IfNotPresentcommand:- sleep- "3600"tolerations:									// 容忍fan=error这个污点- key: "fan"operator: "Equal"value: "error"effect: NoExecute

[root@k8s-master ~]# kubectl get pod -o wide
NAME                         READY   STATUS                   RESTARTS   AGE         IP              NODE                   NOMINATED NODE   READINESS GATES
test5-7575ffc867-hs9hf       1/1     Running                  0          2m1s        10.88.242.129   k8s-node02.linux.com   <none>           <none>
test5-7575ffc867-lp4k2       1/1     Running                  0          2m1s        10.88.201.193   k8s-node01.linux.com   <none>           <none>