集群信息
1. 节点规划
部署k8s集群的节点按照用途可以划分为如下2类角色:
- master:集群的master节点,集群的初始化节点,基础配置不低于2C4G
- slave:集群的slave节点,可以多台,基础配置不低于2C4G
本例为了演示slave节点的添加,会部署一台master+2台slave,节点规划如下:
主机名 | 节点ip | 角色 | 部署组件 |
---|---|---|---|
k8s-master | 192.168.1.61 | master | etcd, kube-apiserver, kube-controller-manager, kubectl, kubeadm, kubelet, kube-proxy, flannel |
k8s-slave1 | 192.168.1.62 | slave | kubectl, kubelet, kube-proxy, flannel |
k8s-slave2 | 192.168.1.63 | slave | kubectl, kubelet, kube-proxy, flannel |
2. 组件版本
组件 | 版本 | 说明 |
---|---|---|
CentOS | 7.6.1810 | |
Kernel | Linux 3.10.0-1062.9.1.el7.x86_64 | |
etcd | 3.3.15 | 使用容器方式部署,默认数据挂载到本地路径 |
coredns | 1.6.2 | |
kubeadm | v1.16.2 | |
kubectl | v1.16.2 | |
kubelet | v1.16.2 | |
kube-proxy | v1.16.2 | |
flannel | v0.11.0 |
安装前准备工作
1. 设置hosts解析
操作节点:所有节点(k8s-master,k8s-slave
)均需执行
- 修改hostname
hostname必须只能包含小写字母、数字、","、"-",且开头结尾必须是小写字母或数字
# 在master节点
$ hostnamectl set-hostname k8s-master #设置master节点的hostname
# 在slave-1节点
$ hostnamectl set-hostname k8s-slave1 #设置slave1节点的hostname
# 在slave-2节点
$ hostnamectl set-hostname k8s-slave2 #设置slave2节点的hostname
- 添加hosts解析
$ cat >>/etc/hosts<
2. 调整系统配置
操作节点: 所有的master和slave节点(k8s-master,k8s-slave
)需要执行
本章下述操作均以k8s-master为例,其他节点均是相同的操作(ip和hostname的值换成对应机器的真实值)
- 设置安全组开放端口
如果节点间无安全组限制(内网机器间可以任意访问),可以忽略,否则,至少保证如下端口可通:
k8s-master节点:TCP:6443,2379,2380,60080,60081UDP协议端口全部打开
k8s-slave节点:UDP协议端口全部打开
- 设置iptables
iptables -P FORWARD ACCEPT
- 关闭swap
swapoff -a
# 防止开机自动挂载 swap 分区
sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
- 关闭selinux和防火墙
sed -ri 's#(SELINUX=).*#\1disabled#' /etc/selinux/config
setenforce 0
systemctl disable firewalld && systemctl stop firewalld
- 修改内核参数
cat < /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward=1
vm.max_map_count=262144
EOF
modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf
- 设置yum源
$ curl -o /etc/yum.repos.d/Centos-7.repo http://mirrors.aliyun.com/repo/Centos-7.repo
$ curl -o /etc/yum.repos.d/docker-ce.repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
$ cat < /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
$ yum clean all && yum makecache
3. 安装docker
操作节点: 所有节点
## 查看所有的可用版本
$ yum list docker-ce --showduplicates | sort -r
##安装旧版本 yum install docker-ce-cli-18.09.9-3.el7 docker-ce-18.09.9-3.el7
## 安装源里最新版本
$ yum install docker-ce
## 配置docker加速
$ mkdir -p /etc/docker
vi /etc/docker/daemon.json
{
"insecure-registries": [
"192.168.1.61:5000"
],
"registry-mirrors" : [
"https://8xpk5wnt.mirror.aliyuncs.com"
]
}
## 启动docker
$ systemctl enable docker && systemctl start docker
部署kubernetes
1. 安装 kubeadm, kubelet 和 kubectl
操作节点: 所有的master和slave节点(k8s-master,k8s-slave
) 需要执行
$ yum install -y kubelet-1.16.2 kubeadm-1.16.2 kubectl-1.16.2 --disableexcludes=kubernetes
## 查看kubeadm 版本
$ kubeadm version
## 设置kubelet开机启动
$ systemctl enable kubelet
2. 初始化配置文件
操作节点: 只在master节点(k8s-master
)执行
$ kubeadm config print init-defaults > kubeadm.yaml
$ cat kubeadm.yaml
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
- system:bootstrappers:kubeadm:default-node-token
token: abcdef.0123456789abcdef
ttl: 24h0m0s
usages:
- signing
- authentication
kind: InitConfiguration
localAPIEndpoint:
advertiseAddress: 192.168.1.61 # apiserver地址,因为单master,所以配置master的节点内网IP
bindPort: 6443
nodeRegistration:
criSocket: /var/run/dockershim.sock
name: k8s-master
taints:
- effect: NoSchedule
key: node-role.kubernetes.io/master
---
apiServer:
timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
type: CoreDNS
etcd:
local:
dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs.com/google_containers # 修改成阿里镜像源
kind: ClusterConfiguration
kubernetesVersion: v1.16.2
networking:
dnsDomain: cluster.local
podSubnet: 10.244.0.0/16 # Pod 网段,flannel插件需要使用这个网段
serviceSubnet: 10.96.0.0/12
scheduler: {}
对于上面的资源清单的文档比较杂,要想完整了解上面的资源对象对应的属性,可以查看对应的 godoc 文档,地址: https://godoc.org/k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta2。
3. 提前下载镜像
操作节点:只在master节点(k8s-master
)执行
# 查看需要使用的镜像列表,若无问题,将得到如下列表
$ kubeadm config images list --config kubeadm.yaml
registry.aliyuncs.com/google_containers/kube-apiserver:v1.16.0
registry.aliyuncs.com/google_containers/kube-controller-manager:v1.16.0
registry.aliyuncs.com/google_containers/kube-scheduler:v1.16.0
registry.aliyuncs.com/google_containers/kube-proxy:v1.16.0
registry.aliyuncs.com/google_containers/pause:3.1
registry.aliyuncs.com/google_containers/etcd:3.3.15-0
registry.aliyuncs.com/google_containers/coredns:1.6.2
# 提前下载镜像到本地
$ kubeadm config images pull --config kubeadm.yaml
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-apiserver:v1.16.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-controller-manager:v1.16.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-scheduler:v1.16.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-proxy:v1.16.0
[config/images] Pulled registry.aliyuncs.com/google_containers/pause:3.1
[config/images] Pulled registry.aliyuncs.com/google_containers/etcd:3.3.15-0
[config/images] Pulled registry.aliyuncs.com/google_containers/coredns:1.6.2
重要更新:如果出现不可用的情况,请使用如下方式来代替:
-
还原kubeadm.yaml的imageRepository
...
imageRepository: k8s.gcr.io
...
## 查看使用的镜像源
kubeadm config images list --config kubeadm.yaml
k8s.gcr.io/kube-apiserver:v1.16.0
k8s.gcr.io/kube-controller-manager:v1.16.0
k8s.gcr.io/kube-scheduler:v1.16.0
k8s.gcr.io/kube-proxy:v1.16.0
k8s.gcr.io/pause:3.1
k8s.gcr.io/etcd:3.3.15-0
k8s.gcr.io/coredns:1.6.2
-
使用docker hub中的镜像源来下载,注意上述列表中要加上处理器架构,通常我们使用的虚拟机都是amd64
$ docker pull mirrorgooglecontainers/kube-scheduler-amd64:v1.16.0
$ docker pull mirrorgooglecontainers/etcd-amd64:3.3.15-0
...
$ docker tag mirrorgooglecontainers/etcd-amd64:3.3.15-0 k8s.gcr.io/etcd:3.3.15-0
4. 初始化master节点
操作节点:只在master节点(k8s-master
)执行
kubeadm init --config kubeadm.yaml
若初始化成功后,最后会提示如下信息:
...
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/
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join 192.168.1.61:6443 --token abcdef.0123456789abcdef \
--discovery-token-ca-cert-hash sha256:1c4305f032f4bf534f628c32f5039084f4b103c922ff71b12a5f0f98d1ca9a4f
接下来按照上述提示信息操作,配置kubectl客户端的认证
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
⚠️注意:此时使用 kubectl get nodes查看节点应该处于notReady状态,因为还未配置网络插件
若执行初始化过程中出错,根据错误信息调整后,执行kubeadm reset后再次执行init操作即可
5. 添加slave节点到集群中
操作节点:所有的slave节点(k8s-slave
)需要执行
在每台slave节点,执行如下命令,该命令是在kubeadm init成功后提示信息中打印出来的,需要替换成实际init后打印出的命令。
kubeadm join 192.168.1.61:6443 --token abcdef.0123456789abcdef \
--discovery-token-ca-cert-hash sha256:1c4305f032f4bf534f628c32f5039084f4b103c922ff71b12a5f0f98d1ca9a4f
6. 安装flannel插件
操作节点:只在master节点(k8s-master
)执行
- 下载flannel的yaml文件
wget https://raw.githubusercontent.com/coreos/flannel/2140ac876ef134e0ed5af15c65e414cf26827915/Documentation/kube-flannel.yml
- 修改配置,指定网卡名称,大概在文件的和170行,190行,添加一行配置:
$ vi kube-flannel.yml
...
containers:
- name: kube-flannel
image: quay.io/coreos/flannel:v0.11.0-amd64
command:
- /opt/bin/flanneld
args:
- --ip-masq
- --kube-subnet-mgr
- --iface=eth0 # 如果机器存在多网卡的话,指定内网网卡的名称,默认不指定的话会找第一块网
resources:
requests:
cpu: "100m"
...
- 执行安装flannel网络插件
# 先拉取镜像,此过程国内速度比较慢
$ docker pull quay.io/coreos/flannel:v0.11.0-amd64
# 执行flannel安装
$ kubectl create -f kube-flannel.yml
7. 设置master节点是否可调度(可选)
操作节点:k8s-master
默认部署成功后,master节点无法调度业务pod,如需设置master节点也可以参与pod的调度,需执行:
$ kubectl taint node k8s-master node-role.kubernetes.io/master:NoSchedule-
8. 验证集群
操作节点: 在master节点(k8s-master
)执行
$ kubectl get nodes #观察集群节点是否全部Ready
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 22h v1.13.3
k8s-slave Ready 22h v1.13.3
创建测试nginx服务
$ kubectl run test-nginx --image=nginx:alpine
查看pod是否创建成功,并访问pod ip测试是否可用
$ kubectl get po -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
test-nginx-5bd8859b98-5nnnw 1/1 Running 0 9s 10.244.1.2 k8s-slave1
$ curl 10.244.1.2
...
Welcome to nginx!
If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.
For online documentation and support please refer to
nginx.org.
Commercial support is available at
nginx.com.
Thank you for using nginx.
9. 部署dashboard
- 部署服务
# 推荐使用下面这种方式
$ wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta5/aio/deploy/recommended.yaml
$ vi recommended.yaml
# 修改Service为NodePort类型
......
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kubernetes-dashboard
spec:
ports:
- port: 443
targetPort: 8443
selector:
k8s-app: kubernetes-dashboard
type: NodePort # 加上type=NodePort变成NodePort类型的服务
......
- 查看访问地址,本例为30133端口
kubectl create -f recommended.yaml
kubectl -n kubernetes-dashboard get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
dashboard-metrics-scraper ClusterIP 10.105.62.124 8000/TCP 31m
kubernetes-dashboard NodePort 10.103.74.46 443:30133/TCP 31m
使用浏览器访问 https://62.234.133.177:30133,其中62.234.133.177为master节点的外网ip地址,chrome目前由于安全限制,测试访问不了,使用firefox可以进行访问。
创建ServiceAccount进行访问
$ vi admin.conf
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: admin
annotations:
rbac.authorization.kubernetes.io/autoupdate: "true"
roleRef:
kind: ClusterRole
name: cluster-admin
apiGroup: rbac.authorization.k8s.io
subjects:
- kind: ServiceAccount
name: admin
namespace: kubernetes-dashboard
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: admin
namespace: kubernetes-dashboard
$ kubectl create -f admin.conf
$ kubectl -n kubernetes-dashboard get secret |grep admin-token
admin-token-fqdpf kubernetes.io/service-account-token 3 7m17s
# 使用该命令拿到token,然后粘贴到
$ kubectl -n kubernetes-dashboard get secret admin-token-fqdpf -o jsonpath={.data.token}|base64 -d
eyJhbGciOiJSUzI1NiIsImtpZCI6Ik1rb2xHWHMwbWFPMjJaRzhleGRqaExnVi1BLVNRc2txaEhETmVpRzlDeDQifQ.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlcm5ldGVzLWRhc2hib2FyZCIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi10b2tlbi1mcWRwZiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50Lm5hbWUiOiJhZG1pbiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6IjYyNWMxNjJlLTQ1ZG...
10. 清理环境
如果你的集群安装过程中遇到了其他问题,我们可以使用下面的命令来进行重置:
$ kubeadm reset
$ ifconfig cni0 down && ip link delete cni0
$ ifconfig flannel.1 down && ip link delete flannel.1
$ rm -rf /var/lib/cni/