安装与重装k8s 1.15.0

CentOS 7.6系统配置

node1节点操作脚本，node2节点修改主机名名字，其他相同
所有节点执行以下脚本

# 修改主机名
echo "node1" > /etc/hostname
hostnamectl set-hostname node1

# 安装nslookup和ifconfig
# nslookup
yum install -y bind-utils
# ifconfig
yum install -y net-tools.x86_64

# 禁用防火墙
systemctl stop firewalld
systemctl disable firewalld

# 禁用SELINUX
setenforce 0
echo SELINUX=disabled >> /etc/selinux/config

# 创建/etc/sysctl.d/k8s.conf文件并添加内容
rm -f /etc/sysctl.d/k8s.conf
touch /etc/sysctl.d/k8s.conf
echo net.bridge.bridge-nf-call-ip6tables=1 >> /etc/sysctl.d/k8s.conf
echo net.bridge.bridge-nf-call-iptables=1 >> /etc/sysctl.d/k8s.conf
echo net.ipv4.ip_forward=1 >> /etc/sysctl.d/k8s.conf
# 使修改生效
modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf

# 配置kube-proxy开启ipvs的前置条件
cat > /etc/sysconfig/modules/ipvs.modules <<EOF
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF
chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules
yum install -y ipset
yum install -y ipvsadm

# 安装Docker并修改docker cgroup driver为systemd
yum install -y yum-utils \
  device-mapper-persistent-data \
  lvm2
yum install -y wget
cd /etc/yum.repos.d/
wget https://download.docker.com/linux/centos/docker-ce.repo
yum install -y --setopt=obsoletes=0   docker-ce-18.09.7-3.el7
systemctl start docker
systemctl enable docker
# 修改各个节点上docker的cgroup driver为systemd，默认是cgroupfs。
# 创建或修改/etc/docker/daemon.json
rm -f /etc/docker/daemon.json
touch /etc/docker/daemon.json
echo -e '{\n"exec-opts": ["native.cgroupdriver=systemd"]\n}' > /etc/docker/daemon.json
# 重启Docker
systemctl restart docker

# 配置kubeadm源
rm -f /etc/yum.repos.d/kubernetes.repo
cat > /etc/yum.repos.d/kubernetes.repo <<EOF
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
       http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

# 安装kubelet、kubeadm 和 kubectl 1.15.0版本
yum makecache fast
# kubernetes-cni 1.0.0版本后生成的/opt/cni/bin目录中没有flannel
yum install -y kubernetes-cni-0.8.6 kubelet-1.15.0 kubeadm-1.15.0 kubectl-1.15.0
# 在各节点开机启动kubelet服务
systemctl enable kubelet.service

# 关闭系统swap
swapoff -a
# 注释SWAP的自动挂载
sed -i 's/.*swap.*/#&/g' /etc/fstab
echo vm.swappiness=0 >> /etc/sysctl.d/k8s.conf
sysctl -p /etc/sysctl.d/k8s.conf

# 拉取pause镜像
docker pull registry.aliyuncs.com/google_containers/pause:3.1
docker tag registry.aliyuncs.com/google_containers/pause:3.1 k8s.gcr.io/pause:3.1
docker rmi registry.aliyuncs.com/google_containers/pause:3.1

# 拉取kube-proxy镜像
docker pull registry.aliyuncs.com/google_containers/kube-proxy:v1.15.0
docker tag registry.aliyuncs.com/google_containers/kube-proxy:v1.15.0 k8s.gcr.io/kube-proxy:v1.15.0
docker rmi registry.aliyuncs.com/google_containers/kube-proxy:v1.15.0

使用kubeadm部署k8s并纳管节点

使用kubeadm init初始化集群

管理面节点执行以下脚本

rm -f kubeadm.yaml
cat > kubeadm.yaml <<EOF
apiVersion: kubeadm.k8s.io/v1beta2
kind: InitConfiguration
localAPIEndpoint:
  # master节点IP
  advertiseAddress: 192.168.3.58
  bindPort: 6443
nodeRegistration:
  taints:
  - effect: PreferNoSchedule
    key: node-role.kubernetes.io/master
---
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
kubernetesVersion: v1.15.0
networking:
  podSubnet: 10.244.0.0/16
EOF

# 拉取镜像
# k8s.gcr.io/kube-apiserver:v1.15.0
# k8s.gcr.io/kube-controller-manager:v1.15.0
# k8s.gcr.io/kube-scheduler:v1.15.0
# k8s.gcr.io/etcd:3.3.10
# k8s.gcr.io/coredns:1.3.1
images=(kube-apiserver:v1.15.0 kube-controller-manager:v1.15.0 kube-scheduler:v1.15.0
 etcd:3.3.10 coredns:1.3.1)
for imageName in ${images[@]} ; do
    docker pull registry.aliyuncs.com/google_containers/$imageName
    docker tag registry.aliyuncs.com/google_containers/$imageName k8s.gcr.io/$imageName
    docker rmi registry.aliyuncs.com/google_containers/$imageName
done

kubeadm init --config kubeadm.yaml

# master配置常规用户如何使用kubectl访问集群
# k8s集群默认需要加密方式访问。把k8s集群的安全配置文件保存到当前用户的.kube目录下，kubectl默认会使用这个目录下的授权信息访问k8s集群。
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

纳管节点

# 从管理面节点上获取join token
kubeadm token create --print-join-command
# 管理面节点IP
kubeadm join 192.168.3.58:6443 --token ...

安装容器网络flannel

echo "199.232.68.133 raw.githubusercontent.com" >> /etc/hosts
kubectl -n kube-system apply -f https://raw.githubusercontent.com/coreos/flannel/bc79dd1505b0c8681ece4de4c0d86c5cd2643275/Documentation/kube-flannel.yml

kube-proxy开启ipvs

修改ConfigMap kube-proxy中的config.conf
kubectl edit cm kube-proxy -n kube-system
把mode改成ipvs。

重启各个节点上的kube-proxy pod
kubectl get pod -n kube-system | grep kube-proxy | awk '{system("kubectl delete pod "$1" -n kube-system")}'

效果图

因虚拟机IP地址改变而重装k8s和纳管

卸载k8s

所有节点执行以下脚本

kubeadm reset -f
rm -rf ~/.kube/
rm -rf /etc/kubernetes/
rm -rf /var/lib/etcd
rm -rf /var/etcd
rm -rf /var/lib/cni/
rm -rf /var/lib/kubelet/*
rm -rf /etc/cni/

重装k8s

# 修改kubeadm.yaml和/etc/hosts里面的ip
hostIp=$(ifconfig ens33 | grep "inet " | awk '{print $2}')
sed -i "s/advertiseAddress:.*/advertiseAddress: ${hostIp}/" kubeadm.yaml
# 初始化集群
kubeadm init --config kubeadm.yaml
# 纳管节点
kubeadm join master_ip:6443 --token ...
# 添加kubectl执行权限
mkdir -p $HOME/.kube
cp /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config
# 安装容器网络
kubectl create -f kube-flannel.yml

参考资料

安装 Flannel 报错：network plugin is not ready: cni config uninitialized

failed to find plugin “flannel” in path [/opt/cni/bin]，k8sNotReady解决方案