k8s 添加 node

￡神魔★判官ぃ 2023-01-06 11:39 132阅读 0赞

当微服务不断增加时，资源不够用，需要增加新的node

# 修改hostname #

hostnamectl set-hostname xxxx

重启生效

# 安装必要的软件 #

yum -y install wget net-tools nfs-utils lrzsz gcc gcc-c++ make cmake\
    libxml2-devel openssl-devel curl curl-devel unzip sudo ntp libaio-devel\
    wget vim ncurses-devel autoconf automake zlib-devel  python-devel\
    epel-release lrzsz  openssh-server socat  ipvsadm conntrack bind-utils epel-release libffi-devel\
    libaio-devel libxml2-devel cmake python-devel\
    device-mapper-persistent-data lvm2 yum-utils

其中`yum-utils`可以方便地管理软件源

# 关闭防火墙 #

systemctl stop firewalld  && systemctl  disable  firewalld
    yum install iptables-services -y
    iptables -F && service iptables save
    service iptables stop && systemctl disable iptables

# 关闭selinux #

sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/sysconfig/selinux
    sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config
    setenforce 0

# 关闭swap #

swapoff -a
    sed -i 's/.*swap.*/#&/' /etc/fstab

# 添加软件源 #

配置安装k8s需要的yum源

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=0
    EOF

配置docker yum源，如果你的很慢，可以选择下方的阿里云docker yum源

#yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
    yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

清理缓存

yum clean all
    yum makecache fast

# 安装docker #

由于CentOS 8 默认使用podman代替Docker，执行  
centos8 先运行：

yum erase podman buildah

yum install -y docker-ce
    
    systemctl enable docker && systemctl start docker
    
    systemctl status docker

> 注意查看docker的状态，是否有异常信息

如提示：

> Centos /var/log/messages Unknown lvalue ‘TasksMax’ in section ‘Service’

解决方案
    #yum install systemd-* -y
    #systemctl status docker.service
     
    验证方案
    # systemctl restart docker.service
    # systemctl status docker.service

> “Not using native diff for overlay2, this may cause degraded performance for building images: opaque flag erroneously copied up, consider update to kernel 4.8 or later to fix” storage-driver=overlay2

表示要升级内核

修改docker配置文件

cat > /etc/docker/daemon.json <<EOF { "exec-opts": ["native.cgroupdriver=systemd"], "log-driver": "json-file", "log-opts": { "max-size": "100m" }, "storage-driver": "overlay2", "storage-opts": [ "overlay2.override_kernel_check=true" ] } EOF

重启docker

systemctl daemon-reload && systemctl restart docker

# 安装k8s #

开启k8s 网络桥接相关内核配置  
设置网桥包经IPTables，core文件生成路径，配置永久生效

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

安装kubeadm,kubelet和kubectl

yum install kubeadm-1.18.0 kubelet-1.18.0 kubectl-1.18.0 -y 
    
     systemctl enable kubelet && systemctl start kubelet

# 加入k8s集群 #

在master节点运行以下命令，查询加入集群的指令：

kubeadm token create --print-join-command

输出类似下面：

kubeadm join 192.168.1.199:6443 --token 7dwluq.x6nypje7h55rnrhl \
        --discovery-token-ca-cert-hash sha256:fa75619ab0bb6273126350a9dbda9aa6c89828c2c4650299fe1647ab510a7e6c

在新节点运行上面的命令即可。

node提示：

> untime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized

表示插件kube-flannel未安装成功，通过是镜像下载过慢，如果手工下载：

docker pull quay.io/coreos/flannel:v0.12.0-amd64

# 常用命令 #

## 删除节点 ##

（1）卸载节点（drain 翻译排出，此时卸载节点，但是没有删除）

kubectl drain < node name > --delete-local-data --force --ignore-daemonsets

（2）删除节点

kubectl delete node

（3）清空init配置，需要删除的节点上执行