K8S集群操作

部署一个容器

创建tomcat容器
kubectl create deployment tomcat6 --image=tomcat:6.0.53-jre8

[root@master k8s]# kubectl get svc
NAME         TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP        9m7s
tomcat6      NodePort    10.96.74.175   <none>        80:32059/TCP   18s

创建成功
deployment.apps/tomcat6 created

开放服务

kubectl expose deployment tomcat6 --port=80 --target-port=8080 --type=NodePort
查看
kubectl get svc
查看更多
kubectl get svc -o wide

查看部署状态

kubectl get all
NAME                           READY   STATUS              RESTARTS   AGE     部署的pod
pod/tomcat6-5f7ccf4cb9-s8p2m   0/1     ContainerCreating   0          28s

NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE     服务
service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   15h

NAME                      READY   UP-TO-DATE   AVAILABLE   AGE            本次部署
deployment.apps/tomcat6   0/1     1            0           28s

NAME                                 DESIRED   CURRENT   READY   AGE        应用复制
replicaset.apps/tomcat6-5f7ccf4cb9   1         1         0       28s

查看pod部署在哪个节点

[root@kmaster ~]# kubectl get all -o wide
NAME                           READY   STATUS              RESTARTS   AGE     IP       NODE   NOMINATED NODE   READINESS GATES
pod/tomcat6-5f7ccf4cb9-s8p2m   0/1     ContainerCreating   0          4m52s   <none>   n1     <none>           <none>

NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE   SELECTOR
service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   15h   <none>

NAME                      READY   UP-TO-DATE   AVAILABLE   AGE     CONTAINERS   IMAGES               SELECTOR
deployment.apps/tomcat6   0/1     1            0           4m52s   tomcat       tomcat:6.0.53-jre8   app=tomcat6

NAME                                 DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES               SELECTOR
replicaset.apps/tomcat6-5f7ccf4cb9   1         1         0       4m52s   tomcat       tomcat:6.0.53-jre8   app=tomcat6,pod-template-hash=5f7ccf4cb9

删除pod

kubectl get all
kubectl delete deployment.apps/tomcat6
kubectl delete service/kubernetes
创建的deployment会管理replicas、replicas控制这pod的数量，有pod故障自动会拉起新的pod


kubectl delete pod/tomcat6-5f7ccf4cb9-4665b

查看名称空间

kubectl get namespaces

强制删除掉线node中的pod

kubectl delete pod [pod name] --force --grace-period=0 -n [namespace]

这里pod没有namespace的话那就用默认的default名称空间
注意：必须加-n参数指明namespace，否则可能报错pod not found。

查看pod所在的命名空间

kubectl get pods --all-namespaces

查看svc 所在的命名空间

kubectl get svc --all-namespaces

查看pod启动状态

kubectl get pod
NAME                 READY     STATUS              RESTARTS   AGE
redis-master-c9gzd   0/1       ContainerCreating   0          17m
kubectl describe pod redis-master-c9gzd

kubectl describe pod  nginx-ingress-controller-xrk82 -n ingress-nginx

扩容pod

kubectl scale --replicas=3 deployment tomcat6

缩容pod

kubectl scale --replicas=0 deployment tomcat6

输出yaml不执行

[root@master /]# kubectl create deployment tomcat7 --image=tomcat:6.0.53-jre8 --dry-run -o yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: tomcat7
  name: tomcat7
spec:
  replicas: 1
  selector:
    matchLabels:
      app: tomcat7
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: tomcat7
    spec:
      containers:
      - image: tomcat:6.0.53-jre8
        name: tomcat
        resources: {}
status: {}

容器pod的yaml指定输出

[root@master /]# kubectl create deployment tomcat7 --image=tomcat:6.0.53-jre8 --dry-run -o yaml > tomcat6.yaml

删除一些无关紧要的配置

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: tomcat6
  name: tomcat6
spec:
  replicas: 3
  selector:
    matchLabels:
      app: tomcat6
  template:
    metadata:
      labels:
        app: tomcat6
    spec:
      containers:
      - image: tomcat:6.0.53-jre8
        name: tomcat

应用yaml

kubectl apply -f tomcat6.yaml

查看以启动的pod的yaml

kubectl get pod tomcat6-5f7ccf4cb9-4665b -o yaml
 kubectl get pod httpd-gv4bl -o yaml -n openebs

一个pod运行多个容器

apiVersion: v1
kind: Pod
metadata:
  labels:
    app: tomcat6-new
  name: tomcat6-new
  namespace: default
spec:
  containers:
  - image: tomcat:6.0.53-jre8
    imagePullPolicy: IfNotPresent
    name: tomcat-new
  - image: nginx
    imagePullPolicy: IfNotPresent
    name: nginx


运行
kubectl apply -f mypod.yaml

查看pod日志输出

1、查看指定pod的日志

kubectl logs <pod_name>

kubectl logs -f <pod_name> #类似tail -f的方式查看(tail -f 实时查看日志文件 tail -f 日志文件log)

2、查看指定pod中指定容器的日志

kubectl logs <pod_name> -c <container_name>

查看所有名称空间的pod

kubectl get pods --all-namespaces

卸载K8S

kubeadm reset  重置
systemctl stop kubelet 停止kubelet