1.k8s常用的資源

k8s yaml的主要組成

apiVersion: v1  api版本
kind: pod   資源類型
metadata:   屬性
spec:       詳細(xì)

k8s_pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: nginx
  labels:
    app: web
spec:
  containers:
    - name: nginx
      image: 10.0.0.11:5000/nginx:1.13
      ports:
        - containerPort: 80

1.構(gòu)建命令
kubectl create -f k8s_pod.yaml
2.查看狀態(tài)
kubectl get pod nginx -o wide
3.描述pod狀態(tài)
kubectl  describe  pod  nginx
4.刪除pod
kubectl  delete   pod  nginx   或者kubectl delete  -f  xxx.yaml
5.編輯pod的配置
kubectl  edit  pod   nginx

這里需要注意的是構(gòu)建會(huì)失敗，因?yàn)閺墓?jié)點(diǎn)下載pod-infrastructure鏡像是從官網(wǎng)衡便，需要紅帽證書，所以我們用下載好的上傳到本地自己的鏡像倉(cāng)庫(kù)谁撼。

改變兩個(gè)從節(jié)點(diǎn)
vim /etc/kubernetes/kubelet
# pod infrastructure container
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-i
mage=10.0.0.11:5000/pod-infrastructure:latest"

systemctl restart kubelet

pod資源:至少由兩個(gè)容器組成,pod基礎(chǔ)容器和業(yè)務(wù)容器組成

pod配置文件2：

apiVersion: v1
kind: Pod
metadata:
  name: test
  labels:
    app: web
spec:
  containers:
    - name: nginx
      image: 10.0.0.11:5000/nginx:1.13
      ports:
        - containerPort: 80
    - name: busybox
      image: 10.0.0.11:5000/busybox:latest
      command: ["sleep","10000"]

pod是k8s最小的資源單位

2.ReplicationController資源

rc:保證指定數(shù)量的pod始終存活,rc通過(guò)標(biāo)簽選擇器來(lái)關(guān)聯(lián)pod
創(chuàng)建一個(gè)rc.yaml文件

apiVersion: v1
kind: ReplicationController
metadata:
  name: nginx
spec:
  replicas: 5
  selector:
    app: myweb
  template:
    metadata:
      labels:
        app: myweb
    spec:
      containers:
      - name: myweb
        image: 10.0.0.11:5000/nginx:1.13
        ports:
        - containerPort: 80

rc的滾動(dòng)升級(jí) 新建一個(gè)nginx-rc1.15.yaml

image.png

升級(jí)
kubectl rolling-update nginx -f nginx-rc1.15.yaml --update-period=10s

回滾
kubectl rolling-update nginx2 -f nginx-rc.yaml --update-period=1s

3. service資源

image.png

service幫助pod暴露端口

創(chuàng)建一個(gè)service

apiVersion: v1
kind: Service
metadata:
  name: myweb
spec:
  type: NodePort  #ClusterIP
  ports:
    - port: 80          #clusterIP
      nodePort: 30000   #nodeport
      targetPort: 80    #podport
  selector:
    app: myweb

#生成svc
kubectl create -f k8s_svc.yaml 

#查看svc的兩種方法
kubectl get svc 
kubectl get service

#查看所有資源類型
kubectl get all -o wide

#確保標(biāo)簽一樣避咆，修改為myweb
kubectl edit svc myweb
    app: myweb
標(biāo)簽需要確保一樣，必須包竹，很重要Ｑ嗫帷＜！
#查看端口是否暴露成功
kubectl describe svc myweb

如何驗(yàn)證它的負(fù)載均衡呢苗缩？

方法一：
#修改副本數(shù)
kubectl scale rc nginx --replicas=2
方法二：
#進(jìn)入容器
kubectl exec -it pod_name /bin/bash
#k8s進(jìn)入容器的方法
[root@k8s-master svc]# kubectl exec -it nginx-5mf4r /bin/bash
root@nginx-5mf4r:/# echo '11111' >/usr/share/nginx/html/index.html 
root@nginx-5mf4r:/# exit

[root@k8s-master svc]# kubectl exec -it nginx-ppjb3 /bin/bash
root@nginx-ppjb3:/# echo '2222' >/usr/share/nginx/html/index.html 
root@nginx-ppjb3:/# exit

添加隨機(jī)端口
[root@k8s-master svc]# vim /etc/kubernetes/apiserver
KUBE_API_ARGS="--service-node-port-range=3000-50000"
[root@k8s-master svc]# systemctl restart kube-apiserver.service

service默認(rèn)使用iptables來(lái)實(shí)現(xiàn)負(fù)載均衡, k8s 1.8新版本中推薦使用lvs(四層負(fù)載均衡)

4.deployment資源

有rc在滾動(dòng)升級(jí)之后,會(huì)造成服務(wù)訪問(wèn)中斷,于是k8s引入了deployment資源

創(chuàng)建deployment

1饵蒂、編輯deploy的yaml文件
cat k8s_deploy.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: 3
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: 10.0.0.11:5000/nginx:1.13
        ports:
        - containerPort: 80
        resources:
          limits:
            cpu: 100m
          requests:
            cpu: 100m
2.編輯實(shí)現(xiàn)負(fù)載的yaml文件
cat k8s_svc.yaml
apiVersion: v1
kind: Service
metadata:
  name: nginx-deployment 
spec:
  type: NodePort  #ClusterIP
  ports:
    - port: 80          #clusterIP
      nodePort: 30001   #nodeport
      targetPort: 80    #podport
  selector:
    app: nginx

方法一：
deployment升級(jí)和回滾

命令行創(chuàng)建deployment

kubectl run   nginx  --image=10.0.0.11:5000/nginx:1.13 --replicas=3 --record

命令行升級(jí)版本

kubectl set image deploy nginx nginx=10.0.0.11:5000/nginx:1.15

查看deployment所有歷史版本

kubectl rollout history deployment nginx

deployment回滾到上一個(gè)版本

kubectl rollout undo deployment nginx

deployment回滾到指定版本

kubectl rollout undo deployment nginx --to-revision=2
方法二：
#修改配置文件中的此行改為nginx 1.15
[root@k8s-master deploy]# kubectl edit deployment nginx-deployment
      - image: 10.0.0.11:5000/nginx:1.15

5.tomcat+mysql練習(xí)

在k8s中容器之間相互訪問(wèn),通過(guò)VIP地址!

1.上傳配置
[root@k8s-master tomcat_demo]# ll
total 16
-rw-r--r-- 1 root root 416 Jan 13 22:46 mysql-rc.yml
-rw-r--r-- 1 root root 145 Jan 13 22:29 mysql-svc.yml
-rw-r--r-- 1 root root 492 Jan 13 23:37 tomcat-rc.yml
-rw-r--r-- 1 root root 162 Jan 13 22:17 tomcat-svc.yml
2.創(chuàng)建
先創(chuàng)建mysql
kubectl create -f mysql-rc.yml
kubectl create -f mysql-svc.yml
kubectl get all -o wide查看mysql虛擬ip
vim tomcat-rc.yml
          - name: MYSQL_SERVICE_HOST
            value: '10.254.146.149'
更改ip
kubectl create -f  tomcat-rc.yml
kubectl create -f tomcat-svc.yml
kubectl get all -o wide
啟動(dòng)成功后登陸

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