kubeadm 部署k8s集群

部署方式:kubeadm ---k8s部署成容器

部署信息:

IP地址   主机名 系统版本 角色
192.168.10.10 k8s-master 7.5 master 
192.168.10.20 k8s-node01 7.5  node
192.168.10.30 k8s-node02 7.5  node

一、系统基础配置

1、设定时钟同步:

# yum install chrony -y

# timedatectl set-timezone Asia/Shanghai  (更改系统时区为上海)

#启动服务
# systemctl start chronyd.service
# systemctl enable chronyd.service

2、设置主机名称解析

# hostnamectl set-hostname k8s-master

cat >> /etc/hosts << EOF
192.168.10.10  k8s-master
192.168.10.20  k8s-node01
192.168.10.30  k8s-node02
EOF

3、关闭iptables或firewalld防火墙

# systemctl stop firewalld.service
# systemctl disable firewalld.service

4、关闭selinux

# sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config  && setenforce 0

5、关闭swap设备

# sed -i '/ swap / s/^(.*)$/#1/g' /etc/fstab #永久

# swapoff -a # 临时

6、内核调整,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 -p

 二、安装docker服务

# wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
# yum -y install docker-ce-18.06.1.ce-3.el7

# systemctl enable docker && systemctl start docker
# docker --version

三、安装Kubernetes

1、配置kubenetes的yum仓库(这里使用阿里云仓库)

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

2、安装kubeadm,kubelet和kubectl

# yum -y install kubelet-1.15.2 kubeadm-1.15.2 kubectl-1.15.2

# rpm -aq kubelet kubectl kubeadm
 
# systemctl enable kubelet

3、配置忽略swap报错

# vim /etc/sysconfig/kubelet
KUBELET_EXTRA_ARGS="--fail-swap-on=false"

4、初始化 Kubernetes Master (只在master节点执行)

kubeadm init 
--apiserver-advertise-address=192.168.10.10 
--image-repository registry.aliyuncs.com/google_containers 
--kubernetes-version v1.15.2 
--service-cidr=10.1.0.0/16 
--pod-network-cidr=10.244.0.0/16 
--ignore-preflight-errors=Swap


......
Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 192.168.10.10:6443 --token 8nvmlq.wbmmws0ymbszk1yb 
    --discovery-token-ca-cert-hash sha256:ec5385c0abbc1cc14c3c9e40f6ca021e8ae24a11e1c557c285882ffe0b20124d 

参数解析:

--kubernetes-version    #指定Kubernetes版本
--image-repository      #由于kubeadm默认是从官网k8s.grc.io下载所需镜像,国内无法访问,所以这里通过--image-repository指定为阿里云镜像仓库地址
--pod-network-cidr      #指定pod网络段
--service-cidr          #指定service网络段
--ignore-preflight-errors=Swap    #忽略swap报错信息

5、按照上面初始化成功提示创建配置文件

[root@k8s-master ~]# mkdir -p $HOME/.kube
[root@k8s-master ~]# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-master ~]# chown $(id -u):$(id -g) $HOME/.kube/config

6、初始化完成后可以看到所需镜像也拉取下来了

[root@k8s-master ~]# docker image ls 
REPOSITORY                                                        TAG                 IMAGE ID            CREATED             SIZE
registry.aliyuncs.com/google_containers/kube-controller-manager   v1.15.2             9f5df470155d        12 months ago       159MB
registry.aliyuncs.com/google_containers/kube-scheduler            v1.15.2             88fa9cb27bd2        12 months ago       81.1MB
registry.aliyuncs.com/google_containers/kube-proxy                v1.15.2             167bbf6c9338        12 months ago       82.4MB
registry.aliyuncs.com/google_containers/kube-apiserver            v1.15.2             34a53be6c9a7        12 months ago       207MB
registry.aliyuncs.com/google_containers/coredns                   1.3.1               eb516548c180        19 months ago       40.3MB
registry.aliyuncs.com/google_containers/etcd                      3.3.10              2c4adeb21b4f        21 months ago       258MB
registry.aliyuncs.com/google_containers/pause                     3.1                 da86e6ba6ca1        2 years ago         742kB
[root@k8s-master ~]# 

7、查看master状态:

[root@k8s-master ~]# kubectl get nodes
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    master   60m   v1.15.2

8、添加flannel网络组件

添加flannel网络组件,(在master执行) 经过实践发现,node节点上必须有quay.io/coreos/flannel的镜像,,不然状态一直为NotReady

flannel地址:https://github.com/coreos/flannel

[root@k8s-master ~]# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

报错:The connection to the server raw.githubusercontent.com was refused - did you specify the right host or port?  

解决办法:

# 在https://www.ipaddress.com/查询raw.githubusercontent.com的真实IP。
sudo vim /etc/hosts
199.232.28.133 raw.githubusercontent.com

如果flannel的pod状态还不正常,可以卸载掉网络

# kubectl delete -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

四、将node加入集群:

[root@k8s-node01 ~]# kubeadm join 192.168.10.10:6443 --token 8nvmlq.wbmmws0ymbszk1yb     
    --discovery-token-ca-cert-hash sha256:ec5385c0abbc1cc14c3c9e40f6ca021e8ae24a11e1c557c285882ffe0b20124d 
    --ignore-preflight-errors=Swap

查看状态:

#  kubectl config view

# kubectl get pods -n kube-system|grep flannel

使用命令查看节点信息时候 node 节点的STATUS 为NotReady

[root@k8s-master ~]# kubectl get nodes
NAME         STATUS     ROLES    AGE    VERSION
k8s-master   Ready      master   108m   v1.15.2
k8s-node01   NotReady   <none>   16m    v1.15.2
k8s-node02   NotReady   <none>   12m    v1.15.2

出现这个错误可以在节点机器上执行journalctl -f -u kubelet查看kubelet的输出日志信息.

# journalctl -f -u kubelet

发现以下错误:

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

我们可以执行命令docker images|grep flannel来查看flannel镜像是否已经成功拉取下来.经过排查master端的已经安装好,node节点没有flannel插件,安装即可.

master需要flannel,node也需要flannel。

# docker save -o flannel.tar quay.io/coreos/flannel

# docker load -i flannel.tar

 

原文地址:https://www.cnblogs.com/saneri/p/14146602.html