前段时间Kubernetes 1.14GA版本发布,而且还有了生产级别的windows节点支持。此文档使用kubeadm搭建Kubernetes1.14 做个记录。此文档在安装了docker的centos7.x的版本下实际操作

环境

此次准备两台机器用于安装。后面可以按需求增加节点

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172.16.77.189
172.16.77.162

前期准备

前期准备很重要,不然后面的安装可能会出现意想不到的坑。

  • 禁用防火墙
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systemctl stop firewalld.service
systemctl disable firewalld.service
  • 关闭swap
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swapoff -a
sed -i '/swap/d'  /etc/fstab
  • 禁用SELINUX
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setenforce 0
sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
  • 配置k8s.conf
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cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF

执行以下命令,使其生效。

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modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf

安装 kubeadm、kubelet、kubectl

在确保docker安装之后再进行以下操作。安装kubeadm,指定yum源安装:

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cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
exclude=kube*
EOF

注意:以上的源需要科学上网。如果不能科学上网的话,可以使用阿里云的源进行安装:

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cat <<EOF > /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
EOF

安装

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yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
systemctl enable kubelet && systemctl start kubelet

配置 kubelet

 如果和docker的cgroup-driver一致,则可跳过这一步

kubelet的cgroup-driver参数要和docker的cgroup-driver保持一致:

查看docker的cgroup-driver

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[root@k8s-77-189 ~]# docker info |grep Cgroup
Cgroup Driver: systemd  
#注意:有的可能是Cgroup Driver: cgroupfs

查看配置文件:/var/lib/kubelet/kubeadm-flags.env

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[root@k8s-77-189 ~]# cat /var/lib/kubelet/kubeadm-flags.env
KUBELET_KUBEADM_ARGS=--cgroup-driver=systemd --network-plugin=cni --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1
#与docker的cgroup-driver参数保持一致

如果你使用其他CRI 请参考此处进行对应修改

 以上所有,master节点和node节点都需要配置

集群安装

初始化

在master节点上使用kubeadm命令进行初始化

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kubeadm init   --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=172.16.77.189

这里选择flannel作为pod的网络插件,所以指定–pod-network-cidr=10.244.0.0/16 。然后是apiserver的通信地址,就是master节点的ip地址。注意:以上命令会在gcr拉取一些镜像 如果你不能科学上网,可能会因为镜像拉取不下来而导致初始化失败。可以加上 –image-repository registry.cn-hangzhou.aliyuncs.com/google_containers来使用阿里云拉取镜像。如果需要指定版本需要使用–kubernetes-version=v1.14.0参数

最后出现以下相似内容说明初始化成功

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[root@k8s-77-189 ~]# kubeadm init   --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=172.16.77.189
......
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 172.16.77.189:6443 --token ye60xn.k9ogcgs2hffr9k97 \
    --discovery-token-ca-cert-hash sha256:277074c8da66ff7008af7ba0b637806facca21e441a5650fc54a83a0a1397bb5

记录下以上内容,里面有配置如何使用kubectl访问集群的方式及将节点加入集群的命令

在master节点上做以下操作操作

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[root@k8s-77-189 ~]# mkdir -p $HOME/.kube
[root@k8s-77-189 ~]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-77-189 ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config

配置好之后可以使用kubectl来查看集群了

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[root@k8s-77-189 ~]# kubectl get nodes
NAME         STATUS   ROLES    AGE     VERSION
k8s-77-189   Ready    master   5h30m   v1.14.2

如果你集群安装过程中遇到了其他问题,可以使用下面的命令来重置:

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kubeadm reset
ifconfig cni0 down && ip link delete cni0
ifconfig flannel.1 down && ip link delete flannel.1
rm -rf /var/lib/cni/

安装Pod Network

安装flannel网络插件

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[root@k8s-77-189 ~]# wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
[root@k8s-77-189 ~]# kubectl apply -f  kube-flannel.yml

如果是多个网卡的话,需要在kube-flannel.yml中使用--iface参数指定集群主机内网网卡的名称,否则可能会出现dns无法解析。flanneld启动参数加上--iface=<iface-name>

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args:
- --ip-masq
- --kube-subnet-mgr
- --iface=eth0

安装完成后使用kubectl get pods命令可以查看到集群中的组件运行状态,如果都是Running状态的话,那么恭喜你,你的master节点安装成功了。

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[root@k8s-77-189 ~]# kubectl get pods --all-namespaces
NAMESPACE     NAME                                 READY   STATUS    RESTARTS   AGE
kube-system   coredns-d5947d4b-jmvbf               1/1     Running   0          3m29s
kube-system   coredns-d5947d4b-tplqp               1/1     Running   0          3m29s
kube-system   etcd-k8s-77-189                      1/1     Running   0          2m33s
kube-system   kube-apiserver-k8s-77-189            1/1     Running   0          2m22s
kube-system   kube-controller-manager-k8s-77-189   1/1     Running   0          2m22s
kube-system   kube-flannel-ds-amd64-7wdl8          1/1     Running   0          64s
kube-system   kube-proxy-9jsrh                     1/1     Running   0          3m29s
kube-system   kube-scheduler-k8s-77-189            1/1     Running   0          2m24s

添加节点

将集群安装之前所有的环境配置完成后,就可以将node加入集群了

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[root@k8s-77-162 ~]# kubeadm join 172.16.77.189:6443 --token ye60xn.k9ogcgs2hffr9k97 \
>     --discovery-token-ca-cert-hash sha256:277074c8da66ff7008af7ba0b637806facca21e441a5650fc54a83a0a1397bb5
[preflight] Running pre-flight checks
	[WARNING Service-Docker]: docker service is not enabled, please run 'systemctl enable docker.service'
	[WARNING Hostname]: hostname "k8s-77-162" could not be reached
	[WARNING Hostname]: hostname "k8s-77-162": lookup k8s-77-162 on 172.16.170.198:53: server misbehaving
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.14" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Activating the kubelet service
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...

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.

[root@k8s-77-162 ~]#

显示上面输出,说明已经加入到集群了。不过此时还不能使用kubectl来获取集群信息。需要将主节点的config文件拷贝到当前节点上

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[root@k8s-77-162 ~]# mkdir -p $HOME/.kube
[root@k8s-77-162 ~]# scp root@172.16.77.189:/root/.kube/config $HOME/.kube
config                                                                                                                      100% 5449     4.3MB/s   00:00

查看集群信息

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[root@k8s-77-162 ~]# kubectl get nodes
NAME         STATUS   ROLES    AGE     VERSION
k8s-77-162   Ready    <none>   7m39s   v1.14.2
k8s-77-189   Ready    master   10h     v1.14.2

到此集群就算是部署成功了

参考

官方

阳明的博客