一、环境准备
1、硬件及版本信息：
cpu&内存：2核心,2G
网络: 每台vm主机2块网卡,一块NAT用于上网，别一块配置成 "仅主机模式"，网段为192.168.100.X
OS：centos7.4
k8s：v1.13.3
docker: 18.09.2
2、一些初始化工作:
关闭防火墙
关闭SELinux
配置ntp
配置hosts
# /etc/hosts文件如下：每台主机都要配置
# tail -3 /etc/hosts
192.168.100.71 master.perry.com master 192.168.100.72 node1.perry.com node1 192.168.100.73 node2.perry.com node2
关闭swap
注释掉/etc/fstab中swap那行,并重启主机生效
# /dev/mapper/centos-swap swap swap defaults 0 0
开启透明网桥
# echo "net.bridge.bridge-nf-call-iptables=1" >> /etc/sysctl.conf
# echo "net.bridge.bridge-nf-call-ip6tables=1" >> /etc/sysctl.conf
# systctl -p
3、配置docker yum仓库
# wget -O /etc/yum.repos.d/docker-ce.repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
4、配置k8s yum仓库
# cat > /etc/yum.repos.d/kubernetes.repo <<EOF
[kubernetes]
name=kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
gpgcheck=1
enabled=1
EOF
二、安装软件
master和node三台主机都安装 docker-ce kubelet kubeadm kubectl
# yum install docker-ce kubelet kubeadm kubectl
三、初始化master
# kubeadm init --kubernetes-version=v1.13.3 --pod-network-cidr=10.244.0.0/16 --service-cidr=10.96.0.0/12 --apiserver-advertise-address=192.168.100.71
1、参数说明：
--kubernetes-version # 指定要安装的k8s版本
--pod-network-cidr # 指定pod网络地址范围
--service-cidr # 指定service网络地址范围
--apiserver-advertise-address #指定api地址，这里配置成了master的私网接口IP
2、kubeadm init时，会因为无法访问google,导致镜像下载失败，解决办法有如下2种：
1）想办法使用代理上google,有朋友要找到好用的代理告诉我下，^_^。
配置docker使用代理，配置完成后，重启docker服务
# vi /usr/lib/systemd/system/docker.service
[Service]
……
Environment="HTTPS_PROXY=http://www.ik8s.io:10080"
Environment="NO_PROXY=127.0.0.0/8,192.168.0.0/16"
……
2）根据kubeadm init执行时的报错提示，可以获知需要下载哪些镜像，这些镜像可以先从阿里云的registry下载，下载完成后再重新打tag，具体操作如下：
[root@master scripts]# cat get_k8s_img_from_aliyun.sh
#!/bin/bash
# need get images
images=(
k8s.gcr.io/kube-apiserver:v1.13.3
k8s.gcr.io/kube-controller-manager:v1.13.3
k8s.gcr.io/kube-scheduler:v1.13.3
k8s.gcr.io/kube-proxy:v1.13.3
k8s.gcr.io/pause:3.1
k8s.gcr.io/etcd:3.2.24
k8s.gcr.io/coredns:1.2.6
)
k8s_registry=k8s.gcr.io
aliyun_registry=registry.cn-hangzhou.aliyuncs.com
# get images from aliyun registry
function get_aliyun_k8s_images() {
for k8s_image in ${images[*]};do
image=` echo $k8s_image | awk -F '/' '{print $2}'`
docker pull $aliyun_registry/google_containers/$image
done
}
# tag images to k8s.gcr.io registry
function tag_images() {
for k8s_image in ${images[*]};do
image=` echo $k8s_image | awk -F '/' '{print $2}'`
docker tag $aliyun_registry/google_containers/$image $k8s_registry/$image
done
}
get_aliyun_k8s_images
tag_images
docker pull quay.io/coreos/flannel:v0.11.0-amd64
docker images
kubeadm init 初始化成功后，可以看到如下信息：
Your Kubernetes master 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/ You can now join any number of machines by running the following on each node as root: kubeadm join 192.168.100.71:6443 --token rfhs54.1i7ol2gt68pmnsl6 --discovery-token-ca-cert-hash sha256:75e6507e0cd820fae522348f40c9a6fd7318e5ebf34829cebafdec0acc368749
四、将node节点加入k8s集群中
node节点需要以下三个镜像
k8s.gcr.io/kube-proxy:v1.13.3
k8s.gcr.io/pause:3.1
quay.io/coreos/flannel:v0.11.0-amd64
#根据maser上 kubeadmin init执行结果的提示，在2台node上分别执行如下命令
# kubeadm join 192.168.100.71:6443 --token rfhs54.1i7ol2gt68pmnsl6 --discovery-token-ca-cert-hash sha256:75e6507e0cd820fae522348f40c9a6fd7318e5ebf34829cebafdec0acc368749
说明：
1）master和node节点上如果 kubeadm执行不成功，或者需要重新执行，需要先使用kubeadm reset 恢复初始状态
2）master和node节点上需要开启kubectl开机自启动 systemctl enable kubectl, 否则主机重启后组件类容器不能启动
五、验证：
1、查看节点信息
kubectl get nodes
[root@master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
master.perry.com Ready master 32h v1.13.3
node1.perry.com Ready <none> 25h v1.13.3
node2.perry.com Ready <none> 25h v1.13.3
六、发布一个service,体验一下k8s
一个简单的Demo,创建/发布/扩容/缩容/
部署myapp应用
1、在master创建一个myapp的应用,副本数量为2 # kubectl run myapp --image=ikubernetes/myapp:v1 --replicas=2 可以通过以下一些命令查看应用的状态等信息 # kubectl get deployment # kubectl get deployment -w # kubectl get deployment # kubectl get pods -o wide 2、发布应用 # kubectl expose deployment myapp --name=myapp --port 80 # kubectl get svc 3、发布应用,外部可以访问 # kubectl eiit svc myapp type: ClusterIP 将 ClusterIP 修改为NodePort kubectl get svc 在集群外部访问http://192.168.100.72:32602/ 4、扩容myapp应用 # kubectl scale --replicas=5 deployment myapp # kubectl get pod -o wide 5、缩容myapp应用 # kubectl scale --replicas=3 deployment myapp # kubectl get pod -o wide 6、滚动更新 # kubectl set image deployment myapp myapp=ikubernetes/myapp:v2 7、查看滚动更新过程 # kubectl rollout status deployment myapp 8、更新完成后，查看镜像版本 # kubectl describe pods myapp-65899575cd-df62l 9、回滚 # kubectl rollout undo deployment myapp 10、删除应用 # kubectl delete deployment myapp # kubectl delete svc myapp