前言
最近正在学习k8s集群的搭建过程，记录下来分享给大家。
准备工作
- visualbox 虚拟机
- centos7 ISO镜像
- 练习的电脑配置要高
搭建kube-master虚拟机
- 名称：kube-master
- 内存：4G
- 硬盘：10G
- 网卡：网卡1和网卡2
- ip：192.168.56.20
注意：vboxnet0可以在全局网络配置里面点击添加！
搭建过程：略
基本环境配置
- 关闭selinux
setenforce 0
sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config- 关闭swap分区或禁用swap文件
swapoff -a
# 注释掉关于swap分区的行
yes | cp /etc/fstab /etc/fstab_bak
cat /etc/fstab_bak |grep -v swap > /etc/fstab- 修改网卡配置
$ vim /etc/sysctl.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
$ sysctl -p- 启用内核模块
$ modprobe -- ip_vs
$ modprobe -- ip_vs_rr
$ modprobe -- ip_vs_wrr
$ modprobe -- ip_vs_sh
$ modprobe -- nf_conntrack_ipv4
$ cut -f1 -d " " /proc/modules | grep -e ip_vs -e nf_conntrack_ipv4
$ vim /etc/sysconfig/modules/ipvs.modules
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4- 关闭防火墙
$ systemctl stop firewalld
$ systemctl disable firewalld
kubectl、kubeadm、kubelet的安装
- 添加Kubernetes的yum源
vim /etc/yum.repos.d/kubernetes.repo
[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- 安装kubelet、kubeadm、kubectl
yum install -y kubelet kubeadm kubectl- 启动kubelet服务
systemctl enable kubelet
systemctl start kubelet此时执行systemctl status kubelet查看服务状态，服务状态应为Error(255)， 如果是其他错误可使用journalctl -xe查看错误信息。
Docker安装和配置
- Docker安装
docker的安装请查看官网文档
$ sudo yum install -y yum-utils
$ sudo yum-config-manager
--add-repo
https://download.docker.com/linux/centos/docker-ce.repo
$ sudo yum install docker-ce docker-ce-cli containerd.io
$ systemctl enable kubelet
$ systemctl start kubelet- 配置cgroup-driver为systemd
#查看cgroup-driver
$ docker info | grep -i cgroup
$ vim /etc/docker/daemon.json
{
"registry-mirrors": ["https://xxx.mirror.aliyuncs.com"],
"exec-opts": ["native.cgroupdriver=systemd"]
}
$ systemctl restart docker
#再次查看cgroup-driver，看看是否配置成功
$ docker info | grep -i cgroupkubeadm安装依赖镜像
这里有篇文章，大家直接参考安装就好！kubeadm安装依赖镜像
以上步骤需要在master节点和node节点执行
配置kube-node-1和kube-node-2虚拟机
- 复制kube-master虚拟机为kube-node-1和kube-node-2
- 修改kube-node-1的ip
以下以kube-node-1为例子
启动kube-node-1和kube-node-2虚拟机并登录，输入下面命令行进行修改：
$ vim /etc/sysconfig/network-scripts/ifcfg-enp0s3
...
IPADDR="10.0.2.21"
...- 修改kube-node-1的hostname
$ hostnamectl set-hostname kube-node-1- 修改/etc/hosts
$ vim /etc/hosts
192.168.56.20 kube-master
192.168.56.21 kube-node-1
192.168.56.22 kube-node-2
# 重新启动虚拟机
$ poweroffMaster节点的配置
- Master节点的初始化
首先选用finnel网络插件
kubeadm init --pod-network-cidr=10.244.0.0/16 --kubernetes-version=v1.19.4 --apiserver-advertise-address=192.168.56.20执行完成之后，输出：
╭─root@kube-master ~
╰─# kubeadm init --pod-network-cidr=10.244.0.0/16 --kubernetes-version=v1.19.4 --apiserver-advertise-addres
s=192.168.56.20
W1122 15:25:25.160860 2916 configset.go:348] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
[init] Using Kubernetes version: v1.19.4
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [kube-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.56.20]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [kube-master localhost] and IPs [192.168.56.20 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [kube-master localhost] and IPs [192.168.56.20 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[apiclient] All control plane components are healthy after 13.007285 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.19" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node kube-master as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node kube-master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: dcr14g.bn6134xsgfjm4dun
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
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 192.168.56.20:6443 --token dcr14g.bn6134xsgfjm4dun \
--discovery-token-ca-cert-hash sha256:83e1bbf9c1007f3a0346302ce763b63154694b22e0671f239674352a91c523f3保存输出中的kubeadm join部分内容，用于添加node节点，或者使用kubeadm token list 和kubeadm token create --print-join-command查看
kubeadm join 192.168.56.20:6443 --token dcr14g.bn6134xsgfjm4dun \
--discovery-token-ca-cert-hash sha256:83e1bbf9c1007f3a0346302ce763b63154694b22e0671f239674352a91c523f3接下来执行剩余的初始化步骤
$ mkdir -p $HOME/.kube
# 替换192.168.56.20为kube-master
$ vim /etc/kubernetes/admin.conf
$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
$ sudo chown $(id -u):$(id -g) $HOME/.kube/config查看nodes和pods：
╭─root@kube-master ~
╰─# kubectl get nodes
NAME STATUS ROLES AGE VERSION
kube-master NotReady master 14m v1.19.4
╭─root@kube-master ~
╰─# kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-f9fd979d6-5vrhh 0/1 Pending 0 13m
kube-system coredns-f9fd979d6-bdwnr 0/1 Pending 0 13m
kube-system etcd-kube-master 1/1 Running 0 14m
kube-system kube-apiserver-kube-master 1/1 Running 0 14m
kube-system kube-controller-manager-kube-master 1/1 Running 0 14m
kube-system kube-proxy-gcbmf 1/1 Running 0 13m
kube-system kube-scheduler-kube-master 1/1 Running 0 14m- finnel插件的安装
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml╭─root@kube-master ~
╰─# kubectl apply -f kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds created监听查看finnel安装情况：
watch kubectl get pods --all-namespacesEvery 2.0s: kubectl get pods --all-namespaces Sun Nov 22 15:50:24 2020
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-f9fd979d6-5vrhh 1/1 Running 0 24m
kube-system coredns-f9fd979d6-bdwnr 1/1 Running 0 24m
kube-system etcd-kube-master 1/1 Running 0 24m
kube-system kube-apiserver-kube-master 1/1 Running 0 24m
kube-system kube-controller-manager-kube-master 1/1 Running 0 24m
kube-system kube-flannel-ds-s4pm6 1/1 Running 0 6m49s
kube-system kube-proxy-gcbmf 1/1 Running 0 24m
kube-system kube-scheduler-kube-master 1/1 Running 0 24m如果中间出现下载不下来可以参考这篇文章解决：https://blog.csdn.net/zyl9746...
- 小技巧：
查看kube-flannel-ds-s4pm6安装情况
kubectl describe pods kube-flannel-ds-s4pm6 -n kube-system
- 测试
╭─root@kube-master ~
╰─# kubectl get nodes -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
kube-master Ready master 33m v1.19.4 192.168.56.20 CentOS Linux 7 (Core) 3.10.0-1160.el7.x86_64 docker://19.3.13 Node节点的初始化
- 查看加入集群的命令
要使node节点加入到master节点中，可以先查看master节点生成的加入信息：
╭─root@kube-master ~
╰─# kubeadm token create --print-join-command
W1122 16:01:20.660775 18089 configset.go:348] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
kubeadm join kube-master:6443 --token inhs8l.e0otb982o462ruk7 --discovery-token-ca-cert-hash sha256:83e1bbf9c1007f3a0346302ce763b63154694b22e0671f239674352a91c523f3- 登录node节点，执行加入集群的命令，完成加入集群操作
以下以kube-node-1为例子
╭─root@kube-node-1 ~
╰─# kubeadm join kube-master:6443 --token inhs8l.e0otb982o462ruk7 --discovery-token-ca-cert-hash sha256:83e1bbf9c1007f3a0346302ce763b63154694b22e0671f239674352a91c523f3- 查看flannel插件执行情况
kubectl get pods --all-namespaces -o wide
这样就完成了k8s集群的所有操作了！
总结
1、我也观看bilibili大佬的视频总结的，有兴趣的可以到这个地址观察视频搭建全过程；
2、k8s需要很多的配置，如果出现问题大家自行搜索解决方案，我在搭建的过程中也参考了好多人的文章；
3、我们首先使用kube-master搭建master虚拟机，而kube-node-1和kube-node-2可以直接复制kube-master虚拟机只要改下ip和hostname即可，比你再去搭建要方便好多；
4、虚拟机可以使用无界面启动，直接在本地通过ssh连接，非常方便。