Kubernetes1.14.2实践 - kubeadm安装K8s

Kubernetes

K8s作为一个容器编排工具，非常的高效、强大，但由于不能KX上网或者没有3个以上的物理机，导致实践起来很困难。这里总结在Windows下Vagrant/Centos7.2环境下1个master节点2个worker节点的安装过程。 (部分参考自k8s中文社区)
k8s Dashboard配置参考：https://segmentfault.com/a/11...

一、 准备Vagrant下三个Centos7.2实例，配置如下：

1. Centos7.2实例配置

    IP地址            节点角色      内存最小值
    192.168.33.10     master        >=2G
    192.168.33.11     worker        >=1G
    192.168.33.12     worker        >=1G
   

二、在master/node1/node2节点上安装kubelet、kubeadm、kubectl

1. 设置主机名hostname，master节点设置主机名为master，另外两个分别设置为node1/node2

   hostnamectl set-hostname master

2. 修改/etc/hosts 文件

    cat <<EOF >>/etc/hosts
    192.168.33.10 master
    192.168.33.11 node1
    192.168.33.12 node2
    EOF

3. 关闭firewalld、selinux、swap

    systemctl stop firewalld
    systemctl disable firewalld
    setenforce 0
    sed -i "s/^SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config
    swapoff -a
    sed -i 's/.*swap.*/#&/' /etc/fstab

4. 配置内核参数，将桥接的IPv4流量传递到iptables的链

    cat > /etc/sysctl.d/k8s.conf <<EOF
    net.bridge.bridge-nf-call-ip6tables = 1
    net.bridge.bridge-nf-call-iptables = 1
    EOF
    sysctl --system 

5. 配置相关yum源为tencent
   yum源配置:

    yum install -y wget
    mkdir /etc/yum.repos.d/bak && mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak
    wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.cloud.tencent.com/repo/centos7_base.repo
    wget -O /etc/yum.repos.d/epel.repo http://mirrors.cloud.tencent.com/repo/epel-7.repo
    yum clean all && yum makecache

   k8s源配置:

    cat <<EOF > /etc/yum.repos.d/kubernetes.repo
    [kubernetes]
    name=Kubernetes
    baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
    enabled=1
    gpgcheck=1
    repo_gpgcheck=1
    gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
    EOF

   docker源配置:

    wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo 

6. 安装docker-ce

    安装docker:
        yum install -y docker-ce-18.06.1.ce-3.el7
        systemctl enable docker && systemctl start docker
        
    配置cgroup为systemd:
       修改/etc/docker/daemon.json
       {
        "exec-opts": ["native.cgroupdriver=systemd"]
       }
       
    重启docker:
        systemctl daemon-reload
        systemctl restart docker

7. 安装kubeadm、kubelet、kubectl

    安装:     
       yum install -y kubelet-1.14.2 kubeadm-1.14.2 kubectl-1.14.2
       
    配置cgroup为systemd: 
       /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf
       修改： Environment="KUBELET_KUBECONFIG_ARGS增加 --cgroup-driver=systemd
       添加一行  Environment="KUBELET_EXTRA_ARGS=--fail-swap-on=false"
       
    重启kubelet:  
       systemctl daemon-reload
       systemctl restart kubelet
       systemctl enable kubelet
       kubeadm config print init-defaults
    

三、配置master节点

1. master节点集群初始化

   kubeadm init --kubernetes-version=1.14.2 --apiserver-advertise-address=192.168.33.10  --image-repository registry.aliyuncs.com/google_containers --service-cidr=10.1.0.0/16  --pod-network-cidr=10.244.0.0/16
   

2. 记录生成token和秘钥，在worker节点加入时需要此信息

    kubeadm join 192.168.33.10:6443 --token iqtrsg.zbd6laamt4vxhopd --discovery-token-ca-cert-hash sha256:0fd40075be0ebe14e6eb04ad2d0b26229551eba1f5f32bbeb064acad687aca36
    

3. 配置kubectl工具

    mkdir -p /root/.kube
    cp /etc/kubernetes/admin.conf /root/.kube/config
    kubectl get nodes

4. 应用flannel网络

    kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/a70459be0084506e4ec919aa1c114638878db11b/Documentation/kube-flannel.yml
    

四、workers加入master节点

1. node1/node2分别加入master(这里为master节点初始化成功后返回的信息，如果忘记参考文章最下面的FYI)

     kubeadm join 192.168.33.10:6443 --token iqtrsg.zbd6laamt4vxhopd --discovery-token-ca-cert-hash sha256:0fd40075be0ebe14e6eb04ad2d0b26229551eba1f5f32bbeb064acad687aca36

五、检查集群状态

kubectl get nodes       

如果节点状态为NotReady, 进行reboot尝试

FYI：

1. 忘记token怎么加入k8s集群？ 生成新的token和秘钥
   master节点:

     kubeadm token create --ttl 0
     kubeadm token list
     openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'

   worker节点:

     kubeadm join 10.167.11.153:6443 --token o4avtg.65ji6b778nyacw68 --discovery-token-ca-cert-hash sha256:2cc3029123db737f234186636330e87b5510c173c669f513a9c0e0da395515b0
   

2. 安装的过程如遇到失败，重置kubeadm

     kubeadm reset
     ifconfig cni0 down
     ip link delete cni0
     ifconfig flannel.1 down
     ip link delete flannel.1
     rm -rf /var/lib/cni/
   
   
   

Created by 苏亚强([e-mail]) on 2019/8/10.