k8s常用命令

节点加入集群生成新的token:

kubeadm token create --print-join-command

 

查询资源的描述信息，也就是yaml的字段意思(这里以deployment为例子)：
kubectl explain deployment
kubectl explain deployment.spc

 

1.命名空间 namespace /ns

方式：1

创建：kubectl create ns hello-ns
删除：kubectl delete ns hello-ns
查询：kubectl get ns

   方式2：万能通用方式：通过yaml模板创建 : 创建ns-ceate.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: hello

创建： kubectl apply -f ns-create.yaml
删除：kubectl delete -f ns-create.yaml

 2.pod相关命令

  方式1：命令行创建

创建：kubectl run nginx --image=nginx
查看：kubectl get pods -A -o wide
查询详情：kubectl describe pod pod名称
删除： kubectl delete pod nginx
查询容器日志： kubectl logs -c 容器名称 pod名称 
进入pod的某个容器：kubectl exec -it pod名称 -c 容器名称 -- 命令：如  kubectl exec -it nginx -c nginx -- /bin/bash

 方式2：万能方式： 创建：kubectl apply -f xxx.yaml  删除 kubectl delete -f xxx.yaml

apiVersion: v1
kind: Pod
metadata:
  name: nignx_tomcat
  labels:
    app: nignx_tomcat
  namespace: hello
spec:
  containers:
    - name: nginx
      image: nginx
      imagePullPolicy: IfNotPresent
    - name: tomcat
      image: tomcat:8.5.68
      imagePullPolicy: IfNotPresent
  restartPolicy: Always

 3.deployment部署相关

方式1.：

创建部署 kubectl -n hello create deploy my-first-deploy --image=nginx --replicas=3
删除部署：kubectl delete deploy my-first-deploy -n hello
扩容和缩容：kubectl scale deploy --current-replicas=3 --replicas=4 my-first-deploy -n hello
滚动更新：kubectl set image deploy mydeployment ngnix-deplyment=nginx:1.9.1 -n hello
查询滚动更新的状态： kubectl rollout status deploy mydeployment -n hello
查询滚动更新的历史记录： kubectl rollout history deploy mydeployment -n hello
回滚到某一个版本： kubectl rollout undo deployment mydeployment --to-revision=1 -n hello

 

  方式2：万能方式： 创建：kubectl apply -f xxx.yaml  删除 kubectl delete -f xxx.yaml    扩容缩容 kubectl edit deployment xxx -n hello

apiVersion: apps/v1
kind: Deployment
metadata:
  name: mydeployment
  namespace: hello
  labels:
    app: mydeployment
spec:
  replicas: 3
  template:
    metadata:
      name: mydeply
      labels:
        app: mydeply
    spec:
      containers:
        - name: ngnix-deplyment
          image: nginx
          imagePullPolicy: IfNotPresent
        - name: tomcat-deplayment
          image: tomcat:8.5.68
          imagePullPolicy: IfNotPresent
      restartPolicy: Always
  selector:
    matchLabels:
      app: mydeply

　3.服务service的创建

    方式1.通过命令行方式创建：

创建service: 将一个deployment暴露成一组服务
1.默认模式基于clusterIp
   先查询deployment的标签
   kubectl get deploy --show-labels -A
   找到对应的标签名称开始创建(-n hello表示命名空间为hello)：
   kubectl expose deployment my-nginx --port=8088 --target-port=80 --type=ClusterIp -n hello
   集群内才能访问(查询服务的IP) 
   kubectl get svc -n hello
   最后访问：http://服务的ip:8088
   其他pod内部访问：服务名称.命名空间:8088 如这里的是 http://my-nginx.hello:8088
2. 基于NodePort (比clusterIp方式多了一种访问方式节点Ip:端口)
   创建方式：kubectl expose deployment my-nginx --port=8088 --target-port=80 --type=NodePort -n hello

   方式2.万能公式，通过yaml模式创建 kubectl apply -f xxx.yaml  删除 kubectl delete -f xxx.yaml

apiVersion: v1
kind: Service
metadata:
  name: hello-service
  namespace: hello
spec:
  selector:
    app: mydeply     #这里的标签要跟deployment中的pod标签对应而不是跟deployment的标签对应，可以过kubectl get pod --show-labels -A 查询pod的标签
  ports:
    - port: 8089
      targetPort: 80
      nodePort: 30033
  type: NodePort

 4. ingress: 可以根据域名来对服务进行转发 下载进行安装： wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v0.47.0/deploy/static/provider/baremetal/deploy.yaml

 

 ingress也是一个服务，通过NodePort方式暴露，我这里暴露的短点是32721

 将服务暴露成ingress服务：

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: hello-ingress
  namespace: hello
  annotations:
    nginx.ingress.kubernetes.io/limit-rps: "1" #限流
spec:
  ingressClassName: nginx
  rules:
    - host: "hello.shop.com"
      http:
        paths:
          - path: "/"
            pathType: Prefix
            backend:
              service:
                name: hello-service
                port:
                  number: 8089
    - host: "hello.tom.com"
      http:
        paths:
          - path: "/kk"
            pathType: Prefix
            backend:
              service:
                name: tomcat-service
                port:
                  number: 8077  #如果service是使用NodePort方式，这里用的是集群内部的那个端口

上面例子：在windows配置域名跟linux其中一台服务器进行映射：

 之后在windows中访问 http://hello.shop.com:32721 就可以访问到hello-service对应的pod了，访问http://hello.tom.com:32721/kk就可以访问到tomcat-service对应的pod了

查询ingress服务：

 容易错的地方：service /deployment/pod/ingress要用相同的命名空间 

 4.存储

   a: nfs存储：原理

 

#所有机器安装
yum install -y nfs-utils

#nfs主节点
echo "/nfs/data/ *(insecure,rw,sync,no_root_squash)" > /etc/exports

mkdir -p /nfs/data
systemctl enable rpcbind --now
systemctl enable nfs-server --now
#配置生效
exportfs -r

#nfs从节点
showmount -e 172.31.0.4

#执行以下命令挂载 nfs 服务器上的共享目录到本机路径 /root/nfsmount
mkdir -p /nfs/data
#将主节点的目录跟从节点关联
mount -t nfs 172.31.0.4:/nfs/data /nfs/data
# 写入一个测试文件
echo "hello nfs server" > /nfs/data/test.txt

创建一个deployment测试：先在任意节点的 /nfs/data下创建一个nginx目录，然后再创建一个index.html

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx-nsf
  name: nginx-nsf
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx-nsf
  template:
    metadata:
      labels:
        app: nginx-nsf
    spec:
      containers:
        - image: nginx
          name: nginx
          volumeMounts:
            - mountPath: /usr/share/nginx/html
              name: index
      volumes:
        - name: index
          nfs:
            path: /nfs/data/nginx
            server: 192.168.233.10

运行后，访问nginx可以访问到你自己写的index.html.删除delpoy再创建，依然可以访问到

b:  PV和PVC的使用：原理：

 在/nfs/data/下创建三个文件夹：pv-01  pv-02  pv-03

#创建三个存储卷 分别是pv-01 pv-02 pv-03并声明大小
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv-01
spec:
  capacity:
    storage: 10M
  accessModes:
    - ReadWriteMany
  storageClassName: nfs
  nfs:
    path: /nfs/data/pv-01
    server: 192.168.233.10
---

apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv-02
spec:
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteMany
  storageClassName: nfs
  nfs:
    path: /nfs/data/pv-02
    server: 192.168.233.10
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv-03
spec:
  capacity:
    storage: 500M
  accessModes:
    - ReadWriteMany
  storageClassName: nfs
  nfs:
    path: /nfs/data/pv-03
    server: 192.168.233.10


---
#创建一个持久化请求，声明需要的内存大小
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nginx-pvc
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 200Mi
  storageClassName: nfs

---
#将pod和pvc进行绑定
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx-deploy-pvc
  name: nginx-deploy-pvc
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx-deploy-pvc
  template:
    metadata:
      labels:
        app: nginx-deploy-pvc
    spec:
      containers:
        - image: nginx
          name: nginx
          volumeMounts:
            - name: html
              mountPath: /usr/share/nginx/html
      volumes:
        - name: html
          persistentVolumeClaim:
            claimName: nginx-pvc

 

查询PV: kubectl get pv
查询PVC: kubectl get pvc

 c:  configMap的使用，一般用来指定配置文件

apiVersion: v1
kind: ConfigMap
metadata:
  name: redis-config
data:
  redis.conf: |
    appendonly yes
---
apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
    - name: redis
      image: redis
      command:
        - redis-server
        - "/redis-master/redis.conf"  #指的是redis容器内部的位置
      ports:
        - containerPort: 6379
      volumeMounts:
        - mountPath: /data
          name: data
        - mountPath: /redis-master
          name: config
  volumes:
    - name: data
      emptyDir: {}
    - name: config
      configMap:
        name: redis-config
        items:
          - key: redis.conf
            path: redis.conf

查询configMap: kubectl get cm
命令行创建configMap:  kubectl create cm redis-conf --from-file=redis.conf
上面创建容器的后，进入容器查询配置 
kubectl exec -it redis -c redis -- /bin/bash
redis-cli命令，然后config get appendonly查询结果是否正确

 d: secret的使用，当我们需要拉取私服镜像需要账号密码的时候，可以通过他来实现：

    创建secret:    kubectl create secret docker-registry my-dokcer-secrect --docker-username=user --docker-password=password --docker-email=email

应用：

apiVersion: v1
kind: Pod
metadata:
  name: private-nginx
spec:
  containers:
  - name: private-nginx
    image: yangxiaohui/nginx:v1.0
  imagePullSecrets:
  - name: my-docker-secret

 e.有状态服务创建：StatefulSet

 

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: statefulset-pvc
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 800M
  storageClassName: nfs
---


apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  ports:
    - port: 80
      name: web
  clusterIP: None
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  serviceName: "nginx"
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - name: nginx
          image: nginx
          ports:
            - containerPort: 80
              name: web
          volumeMounts:
            - name: www
              mountPath: /usr/share/nginx/html
      volumes:
        - name: www
          persistentVolumeClaim:
            claimName: statefulset-pvc

在其他pod中，可以通过域名访问：web-0.nginx.default.svc.cluster.local 或者 web-1.nginx.default.svc.cluster.local，因为statefulset创建的pod,命名都是statefulset的name-0或n

 f: DaemonSet 守护进程，一般用于收集日志用

 

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: fluentd-elasticsearch
  namespace: kube-system
  labels:
    k8s-app: fluentd-logging
spec:
  selector:
    matchLabels:
      name: fluentd-elasticsearch
  template:
    metadata:
      labels:
        name: fluentd-elasticsearch
    spec:
      tolerations:
        # 这些容忍度设置是为了让该守护进程集在控制平面节点上运行
        # 如果你不希望自己的控制平面节点运行 Pod，可以删除它们
        - key: node-role.kubernetes.io/control-plane
          operator: Exists
          effect: NoSchedule
        - key: node-role.kubernetes.io/master
          operator: Exists
          effect: NoSchedule
      containers:
        - name: fluentd-elasticsearch
          image: quay.io/fluentd_elasticsearch/fluentd:v2.5.2
          resources:
            limits:
              memory: 200Mi
            requests:
              cpu: 100m
              memory: 200Mi
          volumeMounts:
            - name: varlog
              mountPath: /var/log
      terminationGracePeriodSeconds: 30
      volumes:
        - name: varlog
          hostPath:
            path: /var/log