kubernetes入门

一、快速入门
    1、关闭防火墙
        systemctl disable firewalld
        systemctl stop firewalld
    2、安装etcd和kubernetes软件
        yum update
        yum install -y etcd kubernetes
    3、启动服务
        systemctl start etcd
        systemctl start docker
        systemctl start kube-apiserver
        systemctl start kube-controller-manager
        systemctl start kube-scheduler
        systemctl start kubelet
        systemctl start kube-proxy
    4、配置
        A、tomcat配置
            a、mkdir /usr/local/k8s
            b、cd /usr/local/k8s
            c、vim mytomcat.rc.yaml
            d、kubectl create -f mytomcat.rc.yaml
            e、vim mytomcat.svc.yaml
            f、kubectl create -f mytomcat.svc.yaml
            g、kubectl get pods
            h、kubectl get svc
    5、问题解决
        A、kubectl get pods（ContainerCreating问题解决）
            kubectl describe pod mytomcat（查看出错信息）
            yum -y install *rhsm*
            wget http://mirror.centos.org/centos/7/os/x86_64/Packages/python-rhsm-certificates-1.19.10-1.el7_4.x86_64.rpm
            rpm2cpio python-rhsm-certificates-1.19.10-1.el7_4.x86_64.rpm | cpio -iv --to-stdout ./etc/rhsm/ca/redhat-uep.pem | tee /etc/rhsm/ca/redhat-uep.pem
            docker pull registry.access.redhat.com/rhel7/pod-infrastructure:latest
        B、kubectl get pods（No resources found问题解决）
            vim /etc/kubernetes/apiserver
            KUBE_ADMISSION_CONTROL删除ServiceAccount,选项
            systemctl restart kube-apiserver
        C、外部网无法访问
            vim /etc/sysctl.conf
            net.ipv4.ip_forward=1（文件末尾添加参数）
            cd /usr/local/k8s
            kubectl replace -f mytomcat.rc.yaml
            kubectl delete svc --all
            kubectl create -f mytomcat.svc.yaml
            iptables -P FORWARD ACCEPT
备注：
1、mytomcat.rc.yaml
apiVersion: v1
kind: ReplicationController
metadata:
  name: mytomcat
spec:
  replicas: 2
  selector:
    app: mytomcat
  template:
    metadata:
      labels:
        app: mytomcat
    spec:
      containers:
      - name: mytomcat
        image: tomcat:8-jre8
        ports: 
        - containerPort: 8080
2、mytomcat.svc.yaml
apiVersion: v1
kind: Service
metadata:
  name: mytomcat
spec:
  type: NodePort
  ports:
  - port: 8080
    nodePort: 30001
  selector:
    app: mytomcat