准备环境
本文基于kubeadm搭建k8s高可用三主三从集群，k8s版本1.16
| 角色 | ip | 机器配置 |
|---|---|---|
| master1 | 192.168.1.77 | 4个CPU,12G内存,60G硬盘 |
| master2 | 192.168.1.78 | 4个CPU,12G内存,60G硬盘 |
| master3 | 192.168.1.79 | 4个CPU,12G内存,60G硬盘 |
| node1 | 192.168.1.80 | 4个CPU,12G内存,60G硬盘 |
| node2 | 192.168.1.81 | 4个CPU,12G内存,50G硬盘 |
| node3 | 192.168.1.82 | 4个CPU,12G内存,50G硬盘 |
| vip（虚拟ip） | 192.168.1.83 |
# 所有机器执行：关闭防火墙
systemctl stop firewalld
systemctl disable firewalld
# 所有机器执行：selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config # 永久
setenforce 0 # 临时
# 所有机器执行：关闭swap
swapoff -a # 临时
sed -ri 's/.*swap.*/#&/' /etc/fstab # 永久
# 所有机器执行：根据规划设置主机名
hostnamectl set-hostname <hostname>
# 所有机器执行：添加hosts文件
cat >> /etc/hosts << EOF
192.168.1.83 master.k8s.io k8s-vip
192.168.1.77 master01.k8s.io master1
192.168.1.78 master02.k8s.io master2
192.168.1.79 master03.k8s.io master3
192.168.1.80 node01.k8s.io node1
192.168.1.81 node02.k8s.io node2
192.168.1.82 node03.k8s.io node3
EOF
# 所有机器执行：将桥接的IPv4流量传递到iptables的链
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
# 所有机器执行：生效
sysctl --system
# 所有机器执行：时间同步
yum install ntpdate -y
ntpdate time.windows.com
所有master节点部署keepalived
安装相关包和keepalived
yum install -y conntrack-tools libseccomp libtool-ltdl
yum install -y keepalived
配置master节点
master节点配置(所有master节点均需要执行)
cat > /etc/keepalived/keepalived.conf <<EOF
! Configuration File for keepalived
global_defs {
router_id k8s
}
vrrp_script check_haproxy {
script "killall -0 haproxy"
interval 3
weight -2
fall 10
rise 2
}
vrrp_instance VI_1 {
state MASTER
interface ens192
virtual_router_id 51
priority 250
advert_int 1
authentication {
auth_type PASS
auth_pass ceb1b3ec013d66163d6ab
}
virtual_ipaddress {
192.168.1.83
}
track_script {
check_haproxy
}
}
EOF
注意：virtual_ipaddress的值是虚拟ip的值，前面已经声明过。
interface的值根据实际情况设置，该值根据ifconfig结果有关：
启动和检查
所有master节点执行：
# 启动keepalived
systemctl start keepalived.service
#设置开机启动
systemctl enable keepalived.service
# 查看启动状态
systemctl status keepalived.service
启动后查看master的网卡信息
ip a s ens192
三台master机器中必然有一台存在虚拟ip
部署haproxy
安装
所有master节点安装haproxy
yum install -y haproxy
配置
三台master节点的配置均相同，配置中声明了后端代理的三个master节点服务器，指定了haproxy运行的端口为16443等，因此16443端口为集群的入口
cat > /etc/haproxy/haproxy.cfg << EOF
#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global
# to have these messages end up in /var/log/haproxy.log you will
# need to:
# 1) configure syslog to accept network log events. This is done
# by adding the '-r' option to the SYSLOGD_OPTIONS in
# /etc/sysconfig/syslog
# 2) configure local2 events to go to the /var/log/haproxy.log
# file. A line like the following can be added to
# /etc/sysconfig/syslog
#
# local2.* /var/log/haproxy.log
#
log 127.0.0.1 local2
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 4000
user haproxy
group haproxy
daemon
# turn on stats unix socket
stats socket /var/lib/haproxy/stats
#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
mode http
log global
option httplog
option dontlognull
option http-server-close
option forwardfor except 127.0.0.0/8
option redispatch
retries 3
timeout http-request 10s
timeout queue 1m
timeout connect 10s
timeout client 1m
timeout server 1m
timeout http-keep-alive 10s
timeout check 10s
maxconn 3000
#---------------------------------------------------------------------
# kubernetes apiserver frontend which proxys to the backends
#---------------------------------------------------------------------
frontend kubernetes-apiserver
mode tcp
bind *:16443
option tcplog
default_backend kubernetes-apiserver
#---------------------------------------------------------------------
# round robin balancing between the various backends
#---------------------------------------------------------------------
backend kubernetes-apiserver
mode tcp
balance roundrobin
server master01.k8s.io 192.168.1.77:6443 check
server master02.k8s.io 192.168.1.78:6443 check
server master03.k8s.io 192.168.1.79:6443 check
#---------------------------------------------------------------------
# collection haproxy statistics message
#---------------------------------------------------------------------
listen stats
bind *:1080
stats auth admin:awesomePassword
stats refresh 5s
stats realm HAProxy Statistics
stats uri /admin?stats
EOF
启动和检查
所有master执行
systemctl enable haproxy
systemctl start haproxy
systemctl status haproxy
检查端口
netstat -lntup|grep haproxy
所有节点安装Docker/kubeadm/kubelet/kubectl
Kubernetes默认CRI（容器运行时）为Docker，因此先安装Docker。
安装docker
yum install -y wget
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-18.06.1.ce-3.el7
systemctl enable docker && systemctl start docker
docker --version
cat > /etc/docker/daemon.json << EOF
{
"registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF
systemctl restart docker
添加阿里云YUM软件源
cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
systemctl restart docker
安装kubeadm，kubelet和kubectl
yum install -y kubelet-1.16.3 kubeadm-1.16.3 kubectl-1.16.3
systemctl enable kubelet
部署Kubernetes Master
创建kubeadm配置文件
在具有vip的master上操作(含有虚拟ip的master)，我这里为master3
mkdir /usr/local/kubernetes/manifests -p
cd /usr/local/kubernetes/manifests/
vi kubeadm-config.yaml
apiServer:
certSANs:
- master1
- master2
- master3
- master.k8s.io
- 192.168.1.83
- 192.168.1.77
- 192.168.1.78
- 192.168.1.79
- 127.0.0.1
extraArgs:
authorization-mode: Node,RBAC
timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta1
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: "master.k8s.io:16443"
controllerManager: {}
dns:
type: CoreDNS
etcd:
local:
dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.16.3
networking:
dnsDomain: cluster.local
podSubnet: 10.244.0.0/16
serviceSubnet: 10.1.0.0/16
scheduler: {}
在vip节点执行kubeadm init
在vip节点执行，我这里是master3
kubeadm init --config kubeadm-config.yaml
按照提示保存以下内容，一会要使用：
kubeadm join master.k8s.io:16443 --token sjvdo1.fer288zrvufxzkha
--discovery-token-ca-cert-hash sha256:e56060a20f0e8eb7db07f17b23e88c0e5094ec9365a9f15fd2f126a6a783be67
--control-plane
按照提示配置环境变量，使用kubectl工具：
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
查看集群状态：
kubectl get nodes
kubectl get cs
kubectl get pods -n kube-system
安装集群网络
在master3节点上执行：
mkdir flannel
cd flannel
vi kube-flannel.yml
---
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
name: psp.flannel.unprivileged
annotations:
seccomp.security.alpha.kubernetes.io/allowedProfileNames: docker/default
seccomp.security.alpha.kubernetes.io/defaultProfileName: docker/default
apparmor.security.beta.kubernetes.io/allowedProfileNames: runtime/default
apparmor.security.beta.kubernetes.io/defaultProfileName: runtime/default
spec:
privileged: false
volumes:
- configMap
- secret
- emptyDir
- hostPath
allowedHostPaths:
- pathPrefix: "/etc/cni/net.d"
- pathPrefix: "/etc/kube-flannel"
- pathPrefix: "/run/flannel"
readOnlyRootFilesystem: false
# Users and groups
runAsUser:
rule: RunAsAny
supplementalGroups:
rule: RunAsAny
fsGroup:
rule: RunAsAny
# Privilege Escalation
allowPrivilegeEscalation: false
defaultAllowPrivilegeEscalation: false
# Capabilities
allowedCapabilities: ['NET_ADMIN', 'NET_RAW']
defaultAddCapabilities: []
requiredDropCapabilities: []
# Host namespaces
hostPID: false
hostIPC: false
hostNetwork: true
hostPorts:
- min: 0
max: 65535
# SELinux
seLinux:
# SELinux is unused in CaaSP
rule: 'RunAsAny'
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: flannel
rules:
- apiGroups: ['extensions']
resources: ['podsecuritypolicies']
verbs: ['use']
resourceNames: ['psp.flannel.unprivileged']
- apiGroups:
- ""
resources:
- pods
verbs:
- get
- apiGroups:
- ""
resources:
- nodes
verbs:
- list
- watch
- apiGroups:
- ""
resources:
- nodes/status
verbs:
- patch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: flannel
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: flannel
subjects:
- kind: ServiceAccount
name: flannel
namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: flannel
namespace: kube-system
---
kind: ConfigMap
apiVersion: v1
metadata:
name: kube-flannel-cfg
namespace: kube-system
labels:
tier: node
app: flannel
data:
cni-conf.json: |
{
"name": "cbr0",
"cniVersion": "0.3.1",
"plugins": [
{
"type": "flannel",
"delegate": {
"hairpinMode": true,
"isDefaultGateway": true
}
},
{
"type": "portmap",
"capabilities": {
"portMappings": true
}
}
]
}
net-conf.json: |
{
"Network": "10.244.0.0/16",
"Backend": {
"Type": "vxlan"
}
}
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: kube-flannel-ds
namespace: kube-system
labels:
tier: node
app: flannel
spec:
selector:
matchLabels:
app: flannel
template:
metadata:
labels:
tier: node
app: flannel
spec:
affinity:
nodeAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
nodeSelectorTerms:
- matchExpressions:
- key: kubernetes.io/os
operator: In
values:
- linux
hostNetwork: true
priorityClassName: system-node-critical
tolerations:
- operator: Exists
effect: NoSchedule
serviceAccountName: flannel
initContainers:
- name: install-cni
image: quay.io/coreos/flannel:v0.13.0-rc2
command:
- cp
args:
- -f
- /etc/kube-flannel/cni-conf.json
- /etc/cni/net.d/10-flannel.conflist
volumeMounts:
- name: cni
mountPath: /etc/cni/net.d
- name: flannel-cfg
mountPath: /etc/kube-flannel/
containers:
- name: kube-flannel
image: quay.io/coreos/flannel:v0.13.0-rc2
command:
- /opt/bin/flanneld
args:
- --ip-masq
- --kube-subnet-mgr
resources:
requests:
cpu: "100m"
memory: "50Mi"
limits:
cpu: "100m"
memory: "50Mi"
securityContext:
privileged: false
capabilities:
add: ["NET_ADMIN", "NET_RAW"]
env:
- name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
volumeMounts:
- name: run
mountPath: /run/flannel
- name: flannel-cfg
mountPath: /etc/kube-flannel/
volumes:
- name: run
hostPath:
path: /run/flannel
- name: cni
hostPath:
path: /etc/cni/net.d
- name: flannel-cfg
configMap:
name: kube-flannel-cfg
安装flannel网络
kubectl apply -f kube-flannel.yml
检查
kubectl get pods -n kube-system
其余master节点加入到集群中
先保证主节点处于ready状态
因为现在master3已经在集群中，我需要把master1和master2加入到集群中
复制密钥及相关文件
在master3中执行
ssh root@192.168.1.77 mkdir -p /etc/kubernetes/pki/etcd
ssh root@192.168.1.78 mkdir -p /etc/kubernetes/pki/etcd
scp /etc/kubernetes/admin.conf root@192.168.1.77:/etc/kubernetes
scp /etc/kubernetes/admin.conf root@192.168.1.78:/etc/kubernetes
scp /etc/kubernetes/pki/{ca.*,sa.*,front-proxy-ca.*} root@192.168.1.77:/etc/kubernetes/pki
scp /etc/kubernetes/pki/{ca.*,sa.*,front-proxy-ca.*} root@192.168.1.78:/etc/kubernetes/pki
scp /etc/kubernetes/pki/etcd/ca.* root@192.168.1.77:/etc/kubernetes/pki/etcd
scp /etc/kubernetes/pki/etcd/ca.* root@192.168.1.78:/etc/kubernetes/pki/etcd
加入集群
在master1和master2中执行刚才保存的语句，带上参数--control-plane表示把master控制节点加入集群
kubeadm join master.k8s.io:16443 --token sjvdo1.fer288zrvufxzkha
--discovery-token-ca-cert-hash sha256:e56060a20f0e8eb7db07f17b23e88c0e5094ec9365a9f15fd2f126a6a783be67
--control-plane
查看集群状态：master3执行
kubectl get nodes
kubectl get pods -n kube-system
master1和master2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
至此，三主的k8s集群搭建成功
添加node节点
三个node节点执行：注意这里去掉了--control-plane参数
kubeadm join master.k8s.io:16443 --token sjvdo1.fer288zrvufxzkha
--discovery-token-ca-cert-hash sha256:e56060a20f0e8eb7db07f17b23e88c0e5094ec9365a9f15fd2f126a6a783be67
集群网络重新安装:master3中执行：
kubectl delete -f kube-flannel.yml
kubectl apply -f kube-flannel.yml
查看所有的pods
kubectl get pods --all-namespaces
检查k8s集群状态：
kubectl get nodes
测试k8s集群
kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --type=NodePort
kubectl get pod,svc
这里暴露的端口是：30683
master节点访问：
node节点访问：
虚拟ip访问：
至此，k8s三主三从高可用集群搭建和测试完毕！