CentOS下的安装测试K8S(守护进程式)
master: 192.168.0.100
node1: 192.168.0.105
node2: 192.168.0.106
一,k8s基本操作命令:
k8s全名:kubernetes,
容器编排工具,说白了就是自动化管理容器的工具。包括:
- 服务自动注册和发现
- 负载均衡
- 健康监测
- 自动申缩
- 冗余容灾
基本操作命令:
创建:kubectl create -f xxx.yaml kubectl apply -f xxx.yaml 查询: kubectl get pod yourPodName kubectl describe pod yourPodName //这个我一般用来排查机器无故没有Running 删除:kubectl delete pod yourPodName 强制删除: kubectl delete pod PODNAME --force --grace-period=0 更新:kubectl replace /path/to/yourNewYaml.yaml
二,k8s_master安装配置:
2.1,关闭selinux,关闭防火墙,升级yum
setenforce 0 systemctl stop firewalld.service yum update
2.2,安装并配置k8s
yum -y install epel-release
yum -y install etcd kubernetes-master
#配置 vi /etc/etcd/etcd.conf vi /etc/kubernetes/apiserver
2.3,启动etcd、kube-apiserver、kube-controller-manager、kube-scheduler等服务,并设置开机启动
for SERVICES in etcd kube-apiserver kube-controller-manager kube-scheduler; do systemctl restart $SERVICES; systemctl enable $SERVICES; systemctl status $SERVICES ; done
2.4,定义flannel网络
etcdctl mk /atomic.io/network/config '{"Network":"172.17.0.0/16"}'
三,k8s_node安装配置:
3.1,关闭selinux,关闭防火墙,升级yum
setenforce 0 systemctl stop firewalld.service yum update
3.2,安装docker,并配置阿里云加速
yum install docker docker -v ##查看版本 service docker start ##开启docker服务才能用其他命令 chkconfig docker on docker images
配置vim /etc/docker/daemon.json
{ "registry-mirrors": [ "https://cd6xo91e.mirror.aliyuncs.com"] }
3.3,安装并配置k8s,,并启动
yum -y install epel-release yum -y install flannel kubernetes-node #配置 vi /etc/sysconfig/flanneld vi /etc/kubernetes/config vi /etc/kubernetes/kubelet
3.4,node节点机上启动kube-proxy,kubelet,docker,flanneld等服务,并设置开机启动
for SERVICES in kube-proxy kubelet docker flanneld; do systemctl restart $SERVICES; systemctl enable $SERVICES; systemctl status $SERVICES; done
四,编排
创建/root/k8s/tomcat01.yaml文件
apiVersion: extensions/v1beta1 kind: Deployment metadata: name: myweb spec: replicas: 3 template: metadata: name: test-namespace labels: app: myweb spec: containers: - name: myweb image: docker.io/nginx:1.18.0-alpine ports: - containerPort: 80 --- apiVersion: v1 kind: Service metadata: name: myweb spec: ports: - port: 80 targetPort: 80 nodePort: 31111 selector: app: myweb type: NodePort
nginx开放的80,如果是tomcat开放的8080,文件里面80都改成8080即可
kubectl create -f tomcat01.yaml
#如果配置错了,创建了一个错误的service和pod,可以用删除命令,配置正确后再重新创建一遍
kubectl delete -f tomcat01.yaml
检查一下pod和service:
kubectl get pods -o wide
kubectl get svc
#如果两个pods的状态都是ContainerCreating,而不是running,说明kubectl create -f xxx操作是失败的,察看日志
kubectl describe pods myweb-3889544643-3sxrb
五、排障,测试
5.1 错误:redhat-ca.crt
解决方法:
yum install *rhsm* -y
5.2 错误:kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Fail
解决方法:
master:
通过环境变量,配置参数
[root@k8s-master dns]# vi ~/.bash_profile #添加下面三行
export DNS_SERVER_IP="10.254.10.2" export DNS_DOMAIN="cluster.local" export DNS_REPLICAS=1
设置 Cluster DNS Service的IP为 10.254.10.2(不能和已分配的IP重复,如10.0.10.0),Cluster DNS的本地域为 cluster.local。
node:
在vi /etc/kubernetes/kubelet 配置文件中添加如下内容即可
KUBE_ARGS="--cluster-dns=10.254.10.2 --cluster-domain=cluster.local" 重启
systemctl daemon-reload; systemctl restart kubelet