实践--pod污点+容忍+标签

落日映苍穹つ 2022-09-05 13:55 178阅读 0赞

1、了解k8s亲和性和反亲和性，以及污点和容忍的概念  
考虑以下场景：  
广州1，深圳2两个zone，现在我们只希望pod实例部署在广州可用区；  
创建一个pod，利用污点创建pod到master节点上。

# 一. 利用污点创建pod到master节点上 #

vim nginx-deployment.yaml

apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nginx-deployment
      labels:
        app: nginx
    spec:
      replicas: 3
      selector:
        matchLabels:
          app: nginx
      template:
        metadata:
          labels:
            app: nginx
        spec:
          containers:
          - name: pod
            image: nginx:1.7.9
            ports:
            - containerPort: 80
          tolerations:
          - key: "node-role.kubernetes.io/master"
            operator: "Exists"

kubectl taint nodes node2 xx1=yy1:NoSchedule  
kubectl taint nodes node3 xx1=yy1:NoSchedule  
给node节点都设置污点

## 使用pod的方式创建（二选一） ##

apiVersion: v1
    kind: Pod
    metadata:
      name: pod-3
      labels:
        app: pod-3
    spec:
      containers:
      - name: nginx-pod3
        image: nginx:1.7.9
        ports:
        - containerPort: 80
      tolerations:
      - key: "node-role.kubernetes.io/master"
        operator: "Equal"
        effect: "NoSchedule"

一样的效果

创建deployment看是不是都创建到node1 也就是master去了  
容忍是根据node1的污点设置的  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2FzdWZlaXlh_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2FzdWZlaXlh_size_16_color_FFFFFF_t_70 1]  
可以看到都创建到master节点了

删除污点

[root@node1 ~]# kubectl taint nodes node3 xx1=yy1:NoSchedule-
    node/node3 untainted
    [root@node1 ~]# kubectl taint nodes node2 xx1=yy1:NoSchedule-
    node/node2 untainted

删除创建的pod

重新get pod -o wide查看发现在node节点上创建出了新的pod  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2FzdWZlaXlh_size_16_color_FFFFFF_t_70 2]

## 补充： ##

如果将docker镜像从一台主机传输到另一台主机

[root@node1 nginx]# docker save -o nginx.tar nginx:1.7.9
    [root@node1 nginx]# scp nginx.tar root@node2:/root/
    [root@node2 ~]# docker load -i nginx.tar

> 如a服务器镜像迁移到b服务器：  
> a:docker save -o 自定义文件名 迁移镜像名:版本  
> b:scp root@a服务器ip:/自定义的文件名 /root/自定义文件名2  
> b:docker load -i 自定义文件名2

# 只希望pod实例部署在广州可用区 #

[root@node1 nginx]# kubectl label node node2 zone=guangzhou
    node/node2 labeled
    [root@node1 nginx]# kubectl get node --show-labels
    NAME    STATUS   ROLES    AGE   VERSION   LABELS
    node1   Ready    master   26d   v1.19.4   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=node1,kubernetes.io/os=linux,node-role.kubernetes.io/master=
    node2   Ready    <none>   26d   v1.19.4   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=node2,kubernetes.io/os=linux,zone=guangzhou
    node3   Ready    <none>   26d   v1.19.4   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=node3,kubernetes.io/os=linux

vim nginx-pod.yaml

apiVersion: v1
    kind: Pod
    metadata:
      name: affinity
      labels:
        app: node-affinity-pod
    spec:
      containers:
      - name: with-node-affinity
        image: nginx:1.7.9
        ports:
        - containerPort: 80
      affinity:
       nodeAffinity:
         requiredDuringSchedulingIgnoredDuringExecution:
              nodeSelectorTerms:
              - matchExpressions:
                - key: zone
                  operator: In
                  values:
                    - guangzhou

[root@node1 nginx]# kubectl apply -f nginx-pod.yml 
    [root@node1 nginx]# kubectl get pod -o wide
    NAME       READY   STATUS        RESTARTS   AGE     IP               NODE    NOMINATED NODE   READINESS GATES
    affinity   1/1     Running       0          3m21s   10.244.104.39    node2   <none>           <none>

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2FzdWZlaXlh_size_16_color_FFFFFF_t_70]: /images/20220829/203af098ef69445b91863339e441a32a.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2FzdWZlaXlh_size_16_color_FFFFFF_t_70 1]: /images/20220829/7de2719467cd427fa663b3aee7073818.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2FzdWZlaXlh_size_16_color_FFFFFF_t_70 2]: /images/20220829/9536efe0450e4b4d858b5612eff2696d.png