k8s有硬件要求,必须运行cpu为2核,内存为2G以上
docker:k8s运行用来运行容器
kubeadm :k8s集群搭建
kubectl: 操作k8s集群客户端
kubelet:运行每个节点容器
1-8 (除了4) 在所有节点执行
1.关闭防火墙,配置免密登录,这点基本所有教程都有
systemctl stop firewalld #防止端口不开放,k8s集群无法启动
2.关闭selinux
setenforce 0
3.关闭swap
- 1
- 2
- 3
- swapoff -a #临时关闭
- free #可以通过这个命令查看swap是否关闭了
- vim /etc/fstab #永久关闭 注释swap那一行(访问内存分区,k8s无法启动)
4.添加主机名与IP对应的关系,免密(这一步可以只在master执行),这一步我为后面传输网络做准备
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- vim /etc/hosts
- 192.168.44.6 tony06
- 192.168.44.4 tony02
-
- ssh-keygen
- cat .ssh/id_rsa.pub >> .ssh/authorized_keys
- chmod 600 .ssh/authorized_keys
-
- # 可以在master生成,然后拷贝到node节点(免密登录,主机之间互相传文件)
- scp -r .ssh root@192.168.44.4:/root
-
5.将桥接的IPV4流量传递到iptables 的链
- 1
- 2
- 3
- 4
- vi /etc/sysctl.d/k8s.conf
-
- net.bridge.bridge-nf-call-ip6tables = 1
- net.bridge.bridge-nf-call-iptables = 1
6.安装Docker及同步时间
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 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
-
- systemctl start docker
- systemctl enable docker
-
- # 同步时间(这一步必须做,否则后面安装flannel可能会有证书错误)
- yum install ntpdate -y
- ntpdate cn.pool.ntp.org
7.添加阿里云YUM软件源
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- vi /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
8.安装kubeadm,kubelet和kubectl
- 1
- 2
- 3
- yum makecache fast
-
- yum install -y kubectl-1.18.0 kubeadm-1.18.0 kubelet-1.18.0 --nogpgcheck
9. 部署Kubernetes Master
初始化master(在master执行)
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- # 第一次初始化比较慢,需要拉取镜像
- kubeadm init \
- --apiserver-advertise-address=192.168.44.4 \ # 换成自己master的IP
- --image-repository registry.aliyuncs.com/google_containers \
- --kubernetes-version v1.18.0 \
- --service-cidr=10.1.0.0/16 \
- --pod-network-cidr=10.244.0.0/16 # 使用flannel网络必须设置成这个cidrKUB
-
- kubeadm init \
- --apiserver-advertise-address=192.168.44.6 \
- --image-repository registry.aliyuncs.com/google_containers \
- --kubernetes-version v1.18.0 \
- --service-cidr=10.1.0.0/16 \
- --pod-network-cidr=10.244.0.0/16
-
- 接下来,将初始化结果中的命令复制出来执行:
- mkdir -p $HOME/.kube
- sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
- sudo chown $(id -u):$(id -g) $HOME/.kube/config
验证状态,发现前两个是pending,get pods 发现是not ready
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- kubectl get pods --all-namespaces
- NAMESPACE NAME READY STATUS RESTARTS AGE
- kube-system coredns-9d85f5447-fhdmx 0/1 Pending 0 100d
- kube-system coredns-9d85f5447-x5wfq 0/1 Pending 0 100d
- kube-system etcd-local1 1/1 Running 0 100d
- kube-system kube-apiserver-local1 1/1 Running 0 100d
- kube-system kube-controller-manager-local1 1/1 Running 0 100d
- kube-system kube-proxy-2trv9 1/1 Running 0 100d
- kube-system kube-scheduler-local1 1/1 Running 0 100d
需要安装flannel
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- # 安装flannel(在master执行)/
- // 1、在线安装
- kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
-
- // 1、离线安装
- 如果kube-flannel.yml无法下载
- 手动配置网路地址
- mkdir /run/flannel/
-
- cat <<EOF> /run/flannel/subnet.env
- FLANNEL_NETWORK=10.244.0.0/16
- FLANNEL_SUBNET=10.244.1.0/24
- FLANNEL_MTU=1450
- FLANNEL_IPMASQ=true
- EOF
-
- # 安装完flannel,将配置拷到node节点,否则添加节点之后状态不对
- scp -r /etc/cni root@192.168.44.4:/etc
-
- # 这一步也要拷贝,否则节点看着正常,但是pod由于网络原因无法创建
- scp -r /run/flannel/ root@192.168.44.4:/run
-
再次初始化
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- # 执行第9步的命令
- kubeadm init ...
-
- 参数
- --kubernetes-version 指定Kubernetes版本
- --apiserver-advertise-address 指定apiserver的监听地址
- --pod-network-cidr 10.244.0.0/16 指定使用flanneld网络
- --apiserver-bind-port api-server 6443的端口
- --ignore-preflight-errors all 跳过之前已安装部分(出问题时,问题解决后加上继续运行)
查看集群状态,master正常
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- [root@local1 ~]# kubectl get cs
- NAME STATUS MESSAGE ERROR
- scheduler Healthy ok
- controller-manager Healthy ok
- etcd-0 Healthy {"health":"true"}
-
- [root@local1 ~]# kubectl get nodes
- NAME STATUS ROLES AGE VERSION
- local1 Ready master 2m16s v1.17.3
-
- [root@local1 ~]# kubectl get pods --all-namespaces
- NAMESPACE NAME READY STATUS RESTARTS AGE
- kube-system coredns-9d85f5447-9s4mc 1/1 Running 0 16m
- kube-system coredns-9d85f5447-gt2nf 1/1 Running 0 16m
- kube-system etcd-local1 1/1 Running 0 16m
- kube-system kube-apiserver-local1 1/1 Running 0 16m
- kube-system kube-controller-manager-local1 1/1 Running 0 16m
- kube-system kube-proxy-sdbl9 1/1 Running 0 15m
- kube-system kube-proxy-v4vxg 1/1 Running 0 16m
- kube-system kube-scheduler-local1 1/1 Running 0
10、node工作节点加载
node节点执行1-8,如果第五步不执行,会添加失败
在node节点执行上面初始化时生成的join命令
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- kubeadm join 192.168.235.145:6443 --token w5rify.gulw6l1yb63zsqsa
- --discovery-token-ca-cert-hash
- sha256:4e7f3a03392a7f9277d9f0ea2210f77d6e67ce0367e824ed891f6fefc7dae3c8
-
- # 输出
- This node has joined the cluster:
- * Certificate signing request was sent to apiserver and a response was received.
- * The Kubelet was informed of the new secure connection details.
-
- Run 'kubectl get nodes' on the control-plane to see this node join the cluster.
在master查看
- 1
- 2
- 3
- 4
- [root@local1 ~]# kubectl get nodes
- NAME STATUS ROLES AGE VERSION
- local1 Ready master 4m58s v1.18.3
- local2 Ready <none> 3m36s v1.18.3
在node节点查看
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- [root@local3 ~]# kubectl get nodes
- Unable to connect to the server: x509: certificate signed by unknown authority (possibly because of "crypto/rsa: verification error" while trying to verify candidate authority certificate "kubernetes")
-
- # 如果报错,需要将master的admin.conf拷贝过来
- # master执行
- scp /etc/kubernetes/admin.conf root@local3:/etc/kubernetes/
-
- # 然后在node执行下面三步
- mkdir -p $HOME/.kube
- sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
- sudo chown $(id -u):$(id -g) $HOME/.kube/config
-
- 再次在node查看
- [root@local3 ~]# kubectl get nodes
- NAME STATUS ROLES AGE VERSION
- local1 Ready master 6m36s v1.18.0
- local2 Ready <none> 31s v1.18.0
- local3 Ready <none> 5m43s v1.18.0
11、如果节点出错,可以移除节点
- 1
- 2
- 3
- 4
- 5
- #重置节点
- kubeadm reset
-
- #删除节点,删除后 数据就从etcd中清除了(可运行kubectl的任一节点中执行)
- kubectl delete node node-1
12、如果加入节点时,token过期,可以重新生成
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 查看token
- kubeadm token list
-
- 默认生成的token有效期是一天,生成永不过期的token
- [root@k8s-master ~]# kubeadm token create --ttl 0
- W0501 09:14:13.887115 38074 validation.go:28] Cannot validate kube-proxy config - no validator is available
- W0501 09:14:13.887344 38074 validation.go:28] Cannot validate kubelet config - no validator is available
-
- 创建token
- [root@k8s-master ~]# openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'
- # token
- 4dc852fb46813f5b1840f06578ba01283c1a12748419ba8f25ce2788419ab1c2
-
- 在worker节点执行join
- kubeadm join 192.168.0.104:6443 --token vahjcu.rhm7864v6l400188 --discovery-token-ca-cert-hash sha256:4dc852fb46813f5b1840f06578ba01283c1a12748419ba8f25ce27