部署简易k8s集群
1.环境准备
准备3台虚拟机（centos-8）并运行以下脚本：
#!/bin/bash
#解决依赖关系
yum install -y yum-utils zlib zlib-devel openssl openssl-devel pcre pcre-devel gcc gcc-c++ autoconf automake make psmisc lsof net-tools vim python3
#关闭防火墙
systemctl stop firewalld
systemctl disable firewalld
#关闭selinux
setenforce 0 #临时关闭
#永久关闭
sed -i '/^SELINUX/ s/enforcing/disabled/' /etc/selinux/config
2.安装docker
2.1卸载旧版本
（保证不会因为残留文件出现意外的bug）
yum remove docker \
docker-client \
docker-client-latest \
docker-common \
docker-latest \
docker-latest-logrotate \
docker-logrotate \
docker-engine
2.2安装yum-utils软件包（提供yum-config-manager 实用程序），配置加速源
yum install -y yum-utils
yum-config-manager \
--add-repo \
http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
2.3安装docker,设置开机自启
yum install -y docker-ce docker-ce-cli containerd.io
systemctl start docker
systemctl enable docker
2.4配置 Docker使用systemd作为默认Cgroup驱动
cat < /etc/docker/daemon.json
{
"exec-opts": ["native.cgroupdriver=systemd"]
}
EOF
#重启docker
systemctl restart docker
2.5关闭swap分区
swapoff -a # 临时
sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab #永久
2.6重新命名主机，在所有主机上上添加如下命令，修改hosts文件
hostnamectl set-hostname master
hostnamectl set-hostname node1
hostnamectl set-hostname node2
cat >> /etc/hosts << EOF
192.168.88.139 master
192.168.88.140 node1
192.168.88.141 node2
EOF
（ip地址根据个人主机ip对应修改）
3.安装kubeadm,kubelet和kubectl
# 添加kubernetes 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
#安装kubeadm,kubelet和kubectl
yum install -y kubelet kubeadm kubectl
#设置开机自启
systemctl enable --now kubelet
4.在master主机执行
4.1部署Kubernetes Master
# 部署Kubernetes Master
kubeadm init \
--apiserver-advertise-address=192.168.88.139 \
--image-repository registry.aliyuncs.com/google_containers \
--service-cidr=10.1.0.0/16 \
--pod-network-cidr=10.244.0.0/16
（192.168.88.139 是master主机ip地址 其他不需要修改）
输出结果
......
Your Kubernetes control-plane 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
Alternatively, if you are the root user, you can run:
export KUBECONFIG=/etc/kubernetes/admin.conf
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 192.168.139.135:6443 --token mndba9.07ioghhw0wfbeayx \
--discovery-token-ca-cert-hash sha256:406d4d6b6c94950e3e95173a19be5720f6e7aeeecb5b4bc9832fd29c680cfcd0
按照提示操作
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
5.node节点执行（加入创建好的集群中）
（复制粘贴master产生的加入集群的token粘贴到node执行）
kubeadm join 192.168.88.139:6443 --token mndba9.07ioghhw0wfbeayx \
--discovery-token-ca-cert-hash sha256:406d4d6b6c94950e3e95173a19be5720f6e7aeeecb5b4bc9832fd29c680cfcd0
输出结果
[preflight] Running pre-flight checks
[WARNING FileExisting-tc]: tc not found in system path
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.5. Latest validated version: 19.03
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the control-plane to see this node join the cluster.
6.安装网络插件(在master节点执行)
[root@master ~]# cat 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": "10.244.0.0/16",
"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:v0.13.1-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:v0.13.1-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
7.部署flannel（master执行）
[root@master ~]# kubectl apply -f kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds created
[root@master ~]# ps aux|grep flannel
root 320372 1.8 1.4 1265920 26824 ? Ssl 11:12 0:00 /opt/bin/flanneld --ip-masq --kube-subnet-mgr
root 321071 0.0 0.0 12324 1088 pts/0 S+ 11:13 0:00 grep --color=auto flannel
8.查看集群状态
#等待节点准备完毕
[root@master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
master Ready control-plane,master 161m v1.20.4
node1 Ready 135m v1.20.4
node2 NotReady 39s v1.20.4
[root@master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
master Ready control-plane,master 163m v1.20.4
node1 Ready 136m v1.20.4
node2 Ready 2m5s v1.20.4
[root@master ~]# kubectl get pod -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-7f89b7bc75-fjq7n 1/1 Running 0 48m
coredns-7f89b7bc75-t5hnq 1/1 Running 0 48m
etcd-master 1/1 Running 0 48m
kube-apiserver-master 1/1 Running 0 48m
kube-controller-manager-master 1/1 Running 0 48m
kube-flannel-ds-kz8t9 1/1 Running 0 17m
kube-flannel-ds-r2q5s 1/1 Running 0 17m
kube-proxy-4jlr6 1/1 Running 0 48m
kube-proxy-ppsr6 1/1 Running 0 22m
kube-scheduler-master 1/1 Running 0 48m