Kubernetes k8s学习命令
Kubernetes_k8s视频教程_带你从基础入门到精通k8s集群视频链接
1. 安装 kubeadm，kubelet 和 kubectl
yum install kubelet-1.19.4 kubeadm-1.19.4 kubectl-1.19.4 -y
2. 查看系统的pods
kubectl get pods -n kube-system
[root@k8smaster ~]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-6d56c8448f-ftw5w 1/1 Running 2 8d
coredns-6d56c8448f-q9bm4 1/1 Running 2 8d
etcd-k8smaster 1/1 Running 3 8d
kube-apiserver-k8smaster 1/1 Running 3 8d
kube-controller-manager-k8smaster 1/1 Running 3 8d
kube-flannel-ds-dmq5n 1/1 Running 2 8d
kube-flannel-ds-mwpk2 1/1 Running 2 8d
kube-proxy-428jk 1/1 Running 3 8d
kube-proxy-cm629 1/1 Running 3 8d
kube-scheduler-k8smaster 1/1 Running 3 8d
3. 在Kubernetes集群中部署一个Nginx，并暴露端口
kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --type=NodePort
kubectl get pod,svc
4. 查看所有的deployments
kubectl get deployment
[root@k8smaster ~]# kubectl get deployment
NAME READY UP-TO-DATE AVAILABLE AGE
nginx 1/1 1 1 7d17h
tomcat 1/1 1 1 7d19h
5. 查看非系统外的所有pods
kubectl get pods
[root@k8smaster ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-6799fc88d8-fkc62 1/1 Running 1 7d17h
tomcat-7d987c7694-g2zmd 1/1 Running 1 7d19h
6. 查看所有的services
查看所有的services。查看所有的services就可以看到所有端口的暴露情况。
kubectl get service
[root@k8smaster ~]# kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 8d
tomcat NodePort 10.96.208.117 <none> 8080:31317/TCP 7d19h
7. 删除一个deployment
deployment删除完以后，对应的pods都会跟着删除。
kubectl delete deployment nginx
[root@k8smaster ~]# kubectl delete deployment nginx
deployment.apps "nginx" deleted
8. 空运行一遍部署并生成yaml文件
kubectl create deployment nginx --image=nginx --dry-run=client -o yaml
kubectl create deployment nginx --image=nginx --dry-run=client -o yaml > depoly.yaml
9. 通过ymal文件来部署
kubectl apply -f depoly.yaml
10. 常见概念关系
Master控制Node --> service --> deployment(控制器) --> pod --> docker
11. 一个完整的deploy.yaml文件
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: springboot-k8s
name: springboot-k8s
spec:
replicas: 1
selector:
matchLabels:
app: springboot-k8s
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: springboot-k8s
spec:
containers:
- image: 38-springboot-k8s-1.0.0-jar
name: 38-springboot-k8s-1-0-0-jar-4b7hj
imagePullPolicy: Never
resources: {}
status: {}
imagePullPolicy: Never代表不去远程仓库拉取
12. 部署k8s控制台
kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.4/aio/deploy/recommended.yaml
查看命名空间
kubectl get pod -n kubernetes-dashboard
13. 三种端口说明
ports:
- name: http
port: 80
targetPort: 80
nodePort: 30008
protocol: TCP
nodePort
nodePort
外部机器（在windows浏览器）可以访问的端口；
比如一个Web应用需要被其他用户访问，那么需要配置type=NodePort，而且配置nodePort=30001，那么其他机器就可以通过浏览器访问scheme://node:30001访问到该服务；
targetPort
容器的端口，与制作容器时暴露的端口一致（Dockerfile中EXPOSE），例如docker.io官方的nginx暴露的是80端口；
port
Kubernetes集群中的各个服务之间访问的端口，虽然mysql容器暴露了3306端口，但外部机器不能访问到mysql服务，因为他没有配置NodePort类型，该3306端口是集群内其他容器需要通过3306端口访问该服务；
14. 查看Ingress转发规则
kubectl get ingress
[root@k8smaster file]# kubectl get ingress
Warning: extensions/v1beta1 Ingress is deprecated in v1.14+, unavailable in v1.22+; use networking.k8s.io/v1 Ingress
NAME CLASS HOSTS ADDRESS PORTS AGE
k8s-ingress <none> www.abc.com 192.168.2.160 80 15h
k8s-ingress-cloud <none> www.cloud.com 192.168.2.160 80 3m19s
15. 查看pods的log
kubectl logs -f spring-cloud-alibaba-provider-5db86d4cc7-p29qb
16. pods的缩放
kubectl scale -n default deployment nginx --replicas=1
16. 生成暴露端口的yaml文件
kubectl expose deploy nginx --port=80 --dry-run=client -o yaml > nginx_service.yaml
生成的暴露端口service文件：
apiVersion: v1
kind: Service
metadata:
creationTimestamp: null
labels:
app: nginx
name: nginx
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: nginx
status:
loadBalancer: {}
应用配置文件：
kubectl apply -f nginx_service.yaml