K8s高可用部署至少需要2台Master主机，为此我们复用上次做etcd集群的4台机器，2台做Master，2台做Worker。也就是说要完成k8s集群的部署，先完成etcd集群的独立部署工作。
参考以前的文章：
/2020/12/09121959-k8s-config.html
/2021/04/23183930-k8s-etcd.html
环境准备
我们用4台centos8.3虚拟机来做配置试验，每台服务都做下面的配置：
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10.10.200.146 DXHJZW146 （master）
10.10.200.147 DXHJZW147 （master）
10.10.200.148 DXHJZW148 （worker）
10.10.200.149 DXHJZW149 （worker）
# 1. 两台master上安装下面软件
yum install -y keepalived
yum install -y haproxy
# 添加ipvs支持
yum install -y nfs-utils ipset ipvsadm
# 2. 下载证书生成工具
https://github.com/cloudflare/cfssl/releases
mv cfssl_1.5.0_linux_amd64 cfssl
mv cfssljson_1.5.0_linux_amd64 cfssljson
mv cfssl-certinfo_1.5.0_linux_amd64 cfssl-certinfo
# 下载相应平台最新版解压之后，将 cfssl、cfssljson、cfssl-certinfo 放入 /usr/bin
# 可执行权限 chmod +x /usr/bin/cfssl*
# 3. 新建立目录
mkdir /opt/etcd/ssl
mkdir /opt/etcd/cfg
mkdir /opt/etcd/data
mkdir /opt/etcd/check
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配置外部ETCD集群的方法参考以前的文章。
注意事项
要想做K8s HA部署，一般启用 ipvs 做路由处理，两台K8s Master服务器一定要启用相关模块：
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# 安装
yum install -y nfs-utils ipset ipvsadm # 安装ipvs支持
# 配置
cat > /etc/sysconfig/modules/ipvs.modules <<EOF
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
modprobe -- nf_conntrack
EOF
# 执行下面三条
chmod 755 /etc/sysconfig/modules/ipvs.modules
bash /etc/sysconfig/modules/ipvs.modules
# 检查
lsmod | grep -e ip_vs -e nf_conntrack_ipv4
# 或者 centos 8.3 的系统，用下面检测
lsmod | grep -e ip_vs -e nf_conntrack
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因为内核版本高（centos 8.3以上）的系统不会再有nf_conntrack_ipv4模块， 它和 nf_conntrack_ipv6合并了，统一到nf_conntrack中了。
初始化第一个Master
先构建下面的初始化配置文件：
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# vi k8s-init.yml
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: 10.10.200.146
bindPort: 6443
nodeRegistration:
criSocket: /var/run/dockershim.sock
name: DXHJZW146
taints: null
---
apiServer:
certSANs:
- DXHJZW145
- DXHJZW146
- DXHJZW147
- DXHJZW148
- DXHJZW149
- DXHJZW157
- 127.0.0.1
- 10.10.200.145
- 10.10.200.146
- 10.10.200.147
- 10.10.200.148
- 10.10.200.149
- cluster.local
- kubernetes
- kubernetes.default
- kubernetes.default.svc
- kubernetes.default.svc.cluster.local
timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: { }
dns:
type: CoreDNS
etcd:
external:
endpoints:
- https://10.10.200.146:2379
- https://10.10.200.147:2379
- https://10.10.200.148:2379
- https://10.10.200.149:2379
caFile: /opt/etcd/ssl/ca.pem
certFile: /opt/etcd/ssl/server.pem
keyFile: /opt/etcd/ssl/server-key.pem
imageRepository: 10.10.200.11:5000
kind: ClusterConfiguration
kubernetesVersion: 1.21.0
controlPlaneEndpoint: 10.10.200.145:6444
networking:
dnsDomain: cluster.local
podSubnet: 10.243.0.0/16
serviceSubnet: 10.19.0.0/16
scheduler: { }
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs
## 1. 开启 IPVS 模式
## （以下6行适合 k8s 1.19前版本）
#---
#apiVersion: kubeproxy.config.k8s.io/v1alpha1
#kind: KubeProxyConfiguration
#featureGates:
# SupportIPVSProxyMode: true
#mode: ipvs
## 2. （以下5行适合 k8s 1.20之后版本）
#...
#kubeProxy:
# config:
# mode: ipvs
#...
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执行K8s初始化：
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kubeadm init --config=k8s-init.yml
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成功之后按提示做好设置即可。
特别注意
上面配置文件末位给出的两种配置都不正确，只能用下面列出的4行才可以正确启动 K8s IPVS 模式。
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---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs
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安装网络插件
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# 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/v1
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/v1
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": "10.243.0.0/16",
"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: 10.10.200.11:5000/coreos/flannel:v0.14.0-rc1
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: 10.10.200.11:5000/coreos/flannel:v0.14.0-rc1
command:
- /opt/bin/flanneld
args:
- --ip-masq
- --kube-subnet-mgr
- --iface-regex="eth*|ens*|eno*"
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
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添加网络插件：
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kubectl apply -f kube-flannel.yml
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添加Master节点
先将第一个Master中 /etc/kubernetes/pki/*所有文件copy到新Master节点对应目录中 /etc/kubernetes/pki/。之后再执行下面的命令：
kubeadm join 10.10.200.145:6444 --token abcdef.0123456789abcdef \
--apiserver-advertise-address 10.10.200.147 \
--discovery-token-ca-cert-hash sha256:xxxxxx \
--control-plane
添加Worker节点
添加Worker节点非常简单，只需要节点装好了docker和kubeadm相关程序，用下面的命令执行即可。
kubeadm join 10.10.200.145:6444 --token abcdef.0123456789abcdef \
--discovery-token-ca-cert-hash sha256:xxxxxx
之后需要将master节点中的 /etc/kubernetes/admin.conf 加入worker节点中对应目录，即可实现worker节点查询集群的状态。
常见问题
上面的方法都没有解决问题，看下面的根本解法：
https://blog.csdn.net/qingyafan/article/details/93519196
https://blog.csdn.net/kenkao/article/details/83960951
https://blog.csdn.net/lswzw/article/details/102543498
其它参考：
https://blog.csdn.net/lswzw/article/details/109027255
https://blog.51cto.com/u_3241766/2467865
https://blog.51cto.com/u_3241766/2094750
https://www.cnblogs.com/ants/p/11489598.html
（完）