参考资料：
https://kubernetes.io/docs/tasks/tools/install-kubeadm/
https://blog.csdn.net/yitaidn/article/details/79937316
https://www.jianshu.com/p/9c7e1c957752
https://www.jianshu.com/p/3ec8945a864f
环境：3台centos7.3虚拟机
10.10.31.202 k8s-master
10.10.31.203 k8s-node1
10.10.31.204 k8s-node2
环境设置：
1 . 系统是centos7.3，不是执行 yum update，不要更新成7.5
[root@szy-k8s-node2 ~]# yum update #最好不好更新7.5此版本为7.3教程
2.关闭防火墙,SELinux,swap(所有节点)
setenforce 0 ：临时关闭,用于关闭selinux防火墙，但重启后失效。
swapoff -a #保证 kubelet 正确运行
systemctl stop firewalld
systemctl disable firewalld #关闭防火墙
执行效果：
[root@szy-k8s-master ~]# systemctl stop firewalld && systemctl disable firewalld
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
Removed symlink /etc/systemd/system/basic.target.wants/firewalld.service.
[root@szy-k8s-master ~]# swapoff -a
[root@szy-k8s-master ~]# setenforce 0
[root@szy-k8s-master ~]# sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config # 修改配置永久生效，需重启
[root@szy-k8s-master ~]# /usr/sbin/sestatus #查看selinux的状态
SELinux status: enabled
SELinuxfs mount: /sys/fs/selinux SELinux root directory: /etc/selinux Loaded policy name: targeted Current mode: permissive Mode from config file: disabled Policy MLS status: enabled Policy deny_unkNown status: allowed Max kernel policy version: 28
组件安装：
1.docker的安装-经常出问题，版本和系统不兼容等问题
或者使用文件docker-packages.tar，每个节点都要安装。
yum install -y docker
systemctl enable docker && systemctl start docker
本人是第二种安装方法：
链接:https://pan.baidu.com/s/1nV_lOOJhNJpqGBq9heNWug 密码:zkfr
tar -xvf docker-packages.tar
cd docker-packages
rpm -Uvh * 或者 yum install local *.rpm 进行安装
docker version #安装完成查看版本
注意：如果docker安装失败，重装步骤：
yum remove docker
yum remove docker-selinu
如果删不干净，就执行下面操作
1.#查看已经安装的docker安装包,列出入校内容
[root@szy-k8s-node2 docker-packages]# rpm -qa|grep docker
docker-common-1.13.1-63.git94f4240.el7.centos.x86_64
docker-client-1.13.1-63.git94f4240.el7.centos.x86_64
2.分别删除
yum -y remove docker-common-1.13.1-63.git94f4240.el7.centos.x86_64
yum -y remove docker-client-1.13.1-63.git94f4240.el7.centos.x86_64
3.删除docker镜像
rm -rf /var/lib/docker
再重新安装
2.给docker配置阿里镜像加速器【如下图，阿里已给出代码】
输入docker info，==记录Cgroup Driver==
Cgroup Driver: cgroupfs
docker和kubelet的cgroup driver需要一致，如果docker不是cgroupfs，则执行
sudo tee /etc/docker/daemon.json <<-'EOF'
{
"registry-mirrors": ["https://XXXX.mirror.aliyuncs.com"],"exec-opts": ["native.cgroupdriver=cgroupfs"]
}
EOF
systemctl daemon-reload && systemctl restart docker
离线安装 kubeadm，kubectl，kubelet
链接:https://pan.baidu.com/s/13zfZKfARUN2s96fPil-8VQ 密码:10am
使用文件kube-packages-1.10.1.tar，每个节点都要安装
kubeadm是集群部署工具
kubectl是集群管理工具，通过command来管理集群
kubelet的k8s集群每个节点的docker管理服务
tar -xvf kube-packages-1.10.1.tar
cd kube-packages-1.10.1
rpm -Uvh * 或者 yum install local *.rpm 进行安装
在所有kubernetes节点上设置kubelet使用cgroupfs，与dockerd保持一致，否则kubelet会启动报错
默认kubelet使用的cgroup-driver=systemd，改为cgroup-driver=cgroupfs
sed -i "s/cgroup-driver=systemd/cgroup-driver=cgroupfs/g" /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
重设kubelet服务，并重启kubelet服务
systemctl daemon-reload && systemctl restart kubelet
关闭swap，及修改iptables，不然后面kubeadm会报错
swapoff -a
vi /etc/fstab #swap一行注释
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system
导入镜像
每个节点都要执行
docker load -i k8s-images-1.10.tar.gz
#一共11个镜像，分别是
k8s.gcr.io/etcd-amd64:3.1.12
k8s.gcr.io/kube-apiserver-amd64:v1.10.1
k8s.gcr.io/kube-controller-manager-amd64:v1.10.1
k8s.gcr.io/kube-proxy-amd64:v1.10.1
k8s.gcr.io/kube-scheduler-amd64:v1.10.1
k8s.gcr.io/pause-amd64:3.1
k8s.gcr.io/k8s-dns-kube-dns-amd64:1.14.8
k8s.gcr.io/k8s-dns-dnsmasq-nanny-amd64:1.14.8
k8s.gcr.io/k8s-dns-sidecar-amd64:1.14.8
k8s.gcr.io/kubernetes-dashboard-amd64:v1.8.3
quay.io/coreos/flannel:v0.9.1-amd64
kubeadm init 部署master节点，只在master节点执行
此处选用最简单快捷的部署方案。etcd、api、controller-manager、 scheduler服务都会以容器的方式运行在master。etcd 为单点，不带证书。etcd的数据会挂载到master节点/var/lib/etcd
init命令注意要指定版本，和pod范围
kubeadm init –kubernetes-version=v1.10.1 –pod-network-cidr=10.244.0.0/16
[root@szy-k8s-master kubernetes]# kubeadm init --kubernetes-version=v1.10.1 --pod-network-cidr=10.244.0.0/16
[init] Using Kubernetes version: v1.10.1
[init] Using Authorization modes: [Node RBAC]
[preflight] Running pre-flight checks.
[WARNING SystemVerification]: docker version is greater than the most recently validated version. Docker version: 18.04.0-ce. Max validated version: 17.03
[WARNING Service-Kubelet]: kubelet service is not enabled,please run 'systemctl enable kubelet.service'
[WARNING Firewalld]: firewalld is active,please ensure ports [6443 10250] are open or your cluster may not function correctly
[WARNING FileExisting-crictl]: crictl not found in system path
Suggestion: go get github.com/kubernetes-incubator/cri-tools/cmd/crictl
[preflight] Starting the kubelet service
[certificates] Generated ca certificate and key.
[certificates] Generated apiserver certificate and key.
[certificates] apiserver serving cert is signed for DNS names [szy-k8s-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.10.31.202]
[certificates] Generated apiserver-kubelet-client certificate and key.
[certificates] Generated etcd/ca certificate and key.
[certificates] Generated etcd/server certificate and key.
[certificates] etcd/server serving cert is signed for DNS names [localhost] and IPs [127.0.0.1]
[certificates] Generated etcd/peer certificate and key.
[certificates] etcd/peer serving cert is signed for DNS names [szy-k8s-master] and IPs [10.10.31.202]
[certificates] Generated etcd/healthcheck-client certificate and key.
[certificates] Generated apiserver-etcd-client certificate and key.
[certificates] Generated sa key and public key.
[certificates] Generated front-proxy-ca certificate and key.
[certificates] Generated front-proxy-client certificate and key.
[certificates] Valid certificates and keys Now exist in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/controller-manager.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/scheduler.conf"
[controlplane] Wrote Static Pod manifest for component kube-apiserver to "/etc/kubernetes/manifests/kube-apiserver.yaml"
[controlplane] Wrote Static Pod manifest for component kube-controller-manager to "/etc/kubernetes/manifests/kube-controller-manager.yaml"
[controlplane] Wrote Static Pod manifest for component kube-scheduler to "/etc/kubernetes/manifests/kube-scheduler.yaml"
[etcd] Wrote Static Pod manifest for a local etcd instance to "/etc/kubernetes/manifests/etcd.yaml"
[init] Waiting for the kubelet to boot up the control plane as Static Pods from directory "/etc/kubernetes/manifests".
[init] This might take a minute or longer if the control plane images have to be pulled.
[apiclient] All control plane components are healthy after 23.002425 seconds
[uploadconfig] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[markmaster] Will mark node szy-k8s-master as master by adding a label and a taint
[markmaster] Master szy-k8s-master tainted and labelled with key/value: node-role.kubernetes.io/master=""
[bootstraptoken] Using token: ou9izo.w3o32jgx1kg7lypl
[bootstraptoken] Configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstraptoken] Configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstraptoken] Configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstraptoken] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[addons] Applied essential addon: kube-dns
[addons] Applied essential addon: kube-proxy
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 10.10.31.202:6443 --token ou9izo.w3o32jgx1kg7lypl --discovery-token-ca-cert-hash sha256:a1e4b696d1bfd4a86b4e352dec58a44facbbe0022bb65200c1d9f8e9414f53c8
记下join的命令，后续node节点加入的时候要用到
执行提示的命令，保存kubeconfig
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
此时执行kubectl get node 已经可以看到master节点，notready是因为还未部署网络插件
[root@szy-k8s-master k8s]# kubectl get node
NAME STATUS ROLES AGE VERSION
szy-k8s-master NotReady master 3m v1.10.1
[root@szy-k8s-master k8s]#
查看所有的pod，kubectl get pod –all-namespaces
kubedns也依赖于容器网络，此时pending是正常的
[root@szy-k8s-master k8s]# kubectl get pod --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system etcd-szy-k8s-master 1/1 Running 0 2m
kube-system kube-apiserver-szy-k8s-master 1/1 Running 0 2m
kube-system kube-controller-manager-szy-k8s-master 1/1 Running 0 2m
kube-system kube-dns-86f4d74b45-gp8zc 0/3 Pending 0 3m
kube-system kube-proxy-kqnfs 1/1 Running 0 3m
kube-system kube-scheduler-szy-k8s-master 1/1 Running 0 2m
配置KUBECONfig变量
[root@szy-k8s-master k8s]# echo "export KUBECONfig=/etc/kubernetes/admin.conf" >> /etc/profile
[root@szy-k8s-master k8s]# source /etc/profile
[root@szy-k8s-master k8s]# echo $KUBECONfig
/etc/kubernetes/admin.conf
部署flannel网络
k8s支持多种网络方案，flannel，calico，openvswitch
此处选择flannel。 在熟悉了k8s部署后，可以尝试其他网络方案
在当前k8s目录下，有kube-flannel.yml
[root@szy-k8s-master k8s]# kubectl apply -f kube-flannel.yml
clusterrole.rbac.authorization.k8s.io "flannel" created
clusterrolebinding.rbac.authorization.k8s.io "flannel" created
serviceaccount "flannel" created
configmap "kube-flannel-cfg" created
daemonset.extensions "kube-flannel-ds" created
[root@szy-k8s-master k8s]# kubectl get node
NAME STATUS ROLES AGE VERSION
szy-k8s-master Ready master 6m v1.10.1
[root@szy-k8s-master k8s]#
kubeadm join 加入node节点
- node节点加入集群
使用之前kubeadm init 生产的join命令，加入成功后，回到master节点查看是否成功
kubeadm join 10.10.31.202:6443 --token ou9izo.w3o32jgx1kg7lypl --discovery-token-ca-cert-hash sha256:a1e4b696d1bfd4a86b4e352dec58a44facbbe0022bb65200c1d9f8e9414f53c8
在节点node1上执行的效果如下：
[root@szy-k8s-node1 ~]# kubeadm join 10.10.31.202:6443 --token ou9izo.w3o32jgx1kg7lypl --discovery-token-ca-cert-hash sha256:a1e4b696d1bfd4a86b4e352dec58a44facbbe0022bb65200c1d9f8e9414f53c8
[preflight] Running pre-flight checks.
[WARNING SystemVerification]: docker version is greater than the most recently validated version. Docker version: 18.04.0-ce. Max validated version: 17.03
[WARNING Service-Kubelet]: kubelet service is not enabled,please run 'systemctl enable kubelet.service'
[WARNING FileExisting-crictl]: crictl not found in system path
Suggestion: go get github.com/kubernetes-incubator/cri-tools/cmd/crictl
[discovery] Trying to connect to API Server "10.10.31.202:6443"
[discovery] Created cluster-info discovery client,requesting info from "https://10.10.31.202:6443"
[discovery] Requesting info from "https://10.10.31.202:6443" again to validate TLS against the pinned public key
[discovery] Cluster info signature and contents are valid and TLS certificate validates against pinned roots,will use API Server "10.10.31.202:6443"
[discovery] Successfully established connection with API Server "10.10.31.202:6443"
This node has joined the cluster:
* Certificate signing request was sent to master and a response
was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the master to see this node join the cluster.
在节点node2上执行的效果如下：
[root@szy-k8s-node2 ~]# kubeadm join 10.10.31.202:6443 --token ou9izo.w3o32jgx1kg7lypl --discovery-token-ca-cert-hash sha256:a1e4b696d1bfd4a86b4e352dec58a44facbbe0022bb65200c1d9f8e9414f53c8
[preflight] Running pre-flight checks.
[WARNING SystemVerification]: docker version is greater than the most recently validated version. Docker version: 18.04.0-ce. Max validated version: 17.03
[WARNING Service-Kubelet]: kubelet service is not enabled,will use API Server "10.10.31.202:6443"
[discovery] Successfully established connection with API Server "10.10.31.202:6443"
This node has joined the cluster:
* Certificate signing request was sent to master and a response
was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the master to see this node join the cluster.
注意问题：
我在其中出现了报错：[discovery] Failed to request cluster info,will try again:
[discovery] Failed to request cluster info,will try again: [Get https://10.10.31.202:6443/api/v1/namespaces/kube-public/configmaps/cluster-info: dial tcp 10.10.31.202:6443: getsockopt:no route to host]
解决方案：防火墙没有关闭，也可能是刚开始时操作了，没有生效。
systemctl stop firewalld
systemctl disable firewalld #关闭防火墙
问题2：[discovery] Failed to request cluster info,will try again: [Get https://10.10.31.202:6443/api/v1/namespaces/kube-public/configmaps/cluster-info: x509: certificate has expired or is not yet valid]
解决方案： 这是因为master节点缺少KUBECONfig变量
#master节点执行
export KUBECONfig=$HOME/.kube/config
#node节点kubeadm reset 再join
kubeadm reset
kubeadm join 10.10.31.202:6443 --token ou9izo.w3o32jgx1kg7lypl --discovery-token-ca-cert-hash sha256:a1e4b696d1bfd4a86b4e352dec58a44facbbe0022bb65200c1d9f8e9414f53c8
部署kubernetes-ui,Dashboard
dashboard是官方的k8s 管理界面，可以查看应用信息及发布应用。dashboard的语言是根据浏览器的语言自己识别的
官方默认的dashboard为https方式，如果用chrome访问会拒绝。本次部署做了修改，方便使用，使用了http方式，用chrome访问正常。
一共需要导入3个yaml文件
kubectl apply -f kubernetes-dashboard-http.yaml
kubectl apply -f admin-role.yaml
kubectl apply -f kubernetes-dashboard-admin.rbac.yaml
实际执行效果如下：
[root@szy-k8s-master k8s]# ll
total 1066600
-rwxr-xr-x. 1 root root 357 Jun 25 11:18 admin-role.yaml
drwxr-xr-x. 2 root root 4096 Apr 11 19:30 docker-packages
-rwxr-xr-x. 1 root root 39577600 Jun 25 11:18 docker-packages.tar
-rwxr-xr-x. 1 root root 999385088 Jun 25 11:18 k8s-images-1.10.tar.gz
-rwxr-xr-x. 1 root root 2801 Jun 25 11:18 kube-flannel.yml
drwxr-xr-x. 2 root root 190 Apr 25 16:27 kube-packages-1.10.1
-rwxr-xr-x. 1 root root 53207040 Jun 25 11:18 kube-packages-1.10.1.tar
-rwxr-xr-x. 1 root root 281 Jun 25 11:18 kubernetes-dashboard-admin.rbac.yaml
-rwxr-xr-x. 1 root root 4267 Jun 25 11:18 kubernetes-dashboard-http.yaml
[root@szy-k8s-master k8s]# kubectl apply -f kubernetes-dashboard-http.yaml
serviceaccount "kubernetes-dashboard" created
role.rbac.authorization.k8s.io "kubernetes-dashboard-minimal" created
rolebinding.rbac.authorization.k8s.io "kubernetes-dashboard-minimal" created
deployment.apps "kubernetes-dashboard" created
service "kubernetes-dashboard" created
[root@szy-k8s-master k8s]# kubectl apply -f admin-role.yaml
clusterrolebinding.rbac.authorization.k8s.io "kubernetes-dashboard" created
[root@szy-k8s-master k8s]# kubectl apply -f kubernetes-dashboard-admin.rbac.yaml
clusterrolebinding.rbac.authorization.k8s.io "dashboard-admin" created
最后检查成果：
[root@szy-k8s-master kubelet]# kubectl get pod --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system etcd-szy-k8s-master 1/1 Running 0 5h
kube-system kube-apiserver-szy-k8s-master 1/1 Running 0 5h
kube-system kube-controller-manager-szy-k8s-master 1/1 Running 0 5h
kube-system kube-dns-86f4d74b45-2zw26 3/3 Running 162 5h
kube-system kube-flannel-ds-ht6pl 1/1 Running 0 5h
kube-system kube-flannel-ds-npgfq 1/1 Running 1 24m
kube-system kube-flannel-ds-rfxv9 1/1 Running 0 24m
kube-system kube-proxy-8pg78 1/1 Running 0 24m
kube-system kube-proxy-gxcvh 1/1 Running 0 24m
kube-system kube-proxy-jgqtp 1/1 Running 0 5h
kube-system kube-scheduler-szy-k8s-master 1/1 Running 0 5h
kube-system kubernetes-dashboard-5c469b58b8-hr4bk 1/1 Running 0 21m
[root@szy-k8s-master kubelet]#
查看界面：
http://10.10.31.202:31000
http://10.10.31.203:31000
http://10.10.31.204:31000
[root@szy-k8s-master kubelet]# kubectl version
Client Version: version.Info{Major:"1",Minor:"10",GitVersion:"v1.10.1",GitCommit:"d4ab47518836c750f9949b9e0d387f20fb92260b",GitTreeState:"clean",BuildDate:"2018-04-12T14:26:04Z",GoVersion:"go1.9.3",Compiler:"gc",Platform:"linux/amd64"}
Server Version: version.Info{Major:"1",BuildDate:"2018-04-12T14:14:26Z",Platform:"linux/amd64"}
[root@szy-k8s-master kubelet]#