1、机器配置
1、服务器配置至少是2G2核的。如果不是则可以在集群初始化后面增加 --ignore-preflight-errors=NumCPU
2、机器列表
IP Hostname
192.168.31.201 k8s-1
192.168.31.202 k8s-2
192.168.31.203 k8s-3
2、系统准备(三台机器全部执行)
1、系统初始化设置
# 关闭selinux
[root@k8s-1 ~]# setenforce 0
[root@k8s-1 ~]# getenforce
Permissive
[root@k8s-1 ~]# sed -i 's/SELINUX=enforcing/SELINUX=disable/' /etc/selinux/config
# 关闭防火墙
systemctl disable --now firewalld
# 关闭swap分区
swapoff -a
修改/etc/fstab
echo 'KUBELET_EXTRA_ARGS="--fail-swap-on=false"' > /etc/sysconfig/kubelet # kubelet忽略swap
# 修改hosts文件
[root@k8s-1 ~]# cat /etc/hosts
192.168.31.201 k8s-1
192.168.31.202 k8s-2
192.168.31.203 k8s-3
# 免密登录
[root@k8s-1 ~]# ssh-keygen -t rsa
[root@k8s-1 .ssh]# for i in k8s-1 k8s-2 k8s-3 ;do ssh-copy-id -i ~/.ssh/id_rsa.pub root@$i; done
# 同步集群时间
ntpdate time1.aliyun.com
# 配置镜像源
curl -o /etc/yum.repos.d/CentOS-Base.repo https://repo.huaweicloud.com/repository/conf/CentOS-7-reg.repo
yum clean all
yum makecache
# 更新系统
yum update -y --exclud=kernel*
# 安装基础常用命令包
yum install wget expect vim net-tools ntp bash-completion ipvsadm ipset jq iptables conntrack sysstat libseccomp -y
2、更新系统内核
# docker 对系统内核要求比较高，最好使用4.4+
# CentOS 7 上启用 ELRepo 仓库
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm
#列出可用的内核相关包
yum --disablerepo="*" --enablerepo="elrepo-kernel" list available
#安装最新的主线稳定内核
yum --enablerepo=elrepo-kernel install kernel-ml -y
#设置 GRUB 默认的内核版本
sed -i 's/GRUB_DEFAULT=saved/GRUB_DEFAULT=0/' /etc/default/grub
#重新创建内核配置
[root@k8s-1 ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.13.9-1.el7.elrepo.x86_64
Found initrd image: /boot/initramfs-5.13.9-1.el7.elrepo.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-1160.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-1160.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-2ca1aaaa44ad406d975cabc854d4c822
Found initrd image: /boot/initramfs-0-rescue-2ca1aaaa44ad406d975cabc854d4c822.img
done
[root@k8s-1 ~]# reboot
[root@k8s-1 ~]# uname -ra
Linux k8s-1 5.13.9-1.el7.elrepo.x86_64 #1 SMP Sat Aug 7 08:55:16 EDT 2021 x86_64 x86_64 x86_64 GNU/Linux
3、安装IPVS
yum install -y conntrack-tools ipvsadm ipset conntrack libseccomp
# 加载IPVS模块
cat > /etc/sysconfig/modules/ipvs.modules <<EOF
#!/bin/bash
ipvs_modules="ip_vs ip_vs_lc ip_vs_wlc ip_vs_rr ip_vs_wrr ip_vs_lblc ip_vs_lblcr ip_vs_dh ip_vs_sh ip_vs_fo ip_vs_nq ip_vs_sed ip_vs_ftp nf_conntrack"
for kernel_module in ${ipvs_modules}; do
/sbin/modinfo -F filename ${kernel_module} > /dev/null 2>&1
if [ $? -eq 0 ]; then
/sbin/modprobe ${kernel_module}
fi
done
EOF
chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep ip_vs
# 修改内核启动参数
cat > /etc/sysctl.d/k8s.conf << EOF
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
fs.may_detach_mounts = 1
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_watches=89100
fs.file-max=52706963
fs.nr_open=52706963
net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp.keepaliv.probes = 3
net.ipv4.tcp_keepalive_intvl = 15
net.ipv4.tcp.max_tw_buckets = 36000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp.max_orphans = 327680
net.ipv4.tcp_orphan_retries = 3
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.ip_conntrack_max = 65536
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.top_timestamps = 0
net.core.somaxconn = 16384
EOF
# 立即生效
sysctl --system
3、安装Docker(三台机器都要安装)
# 卸载之前安装过的docker
yum remove docker docker-common docker-selinux docker-engine -y
# 安装docker需要的依赖包
yum install -y yum-utils device-mapper-persistent-data lvm2 -y
# 安装dockeryum源
wget -O /etc/yum.repos.d/docker-ce.repo https://repo.huaweicloud.com/docker-ce/linux/centos/docker-ce.repo
# 安装docker
yum install docker-ce -y
# 设置开机自启动
systemctl enable --now docker.service
5、安装kubelet(三台机器都要安装)
# 安装 kebenetes 源
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
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kubelet
yum install -y kubelet-1.21.2-0.x86_64 kubeadm-1.21.2-0.x86_64 kubectl-1.21.2-0.x86_64
systemctl enable --now kubelet
6、镜像下载
由于kubernetes的相关镜像需要翻墙才能够进行下载，所以我们需要将镜像部署到我们的国内镜像仓库，然后再pull到我们本地的服务器。这里我们需要借用阿里云的容器镜像服务。
具体流程：
登录阿里云账号 ---> 进入控制台 ---> 搜索
容器镜像服务---> 创建个人实例 ---> 创建命名空间 ---> 创建镜像仓库 ---> 绑定代码源 ---> 添加构建规则 ---> 构建镜像 ---> 根据基本信息中的操作指南进行登录、拉去镜像 ---> docker tag 更改镜像名称，更改为官方名称
由于我的阿里云服账号，个人实例已经创建过了，就简单的给大家看一下之后的操作步骤。
1、源代码仓库
Github地址：https://github.com/Fong007/images，大家可以自己fork到自己的GitHub上，然后进行编辑`Dockerfile来选择下载镜像的版本。
2、创建镜像仓库
3、添加源代码
4、构建规则
5、如何构建镜像
6、pull镜像
将所有的镜像pull到本地服务上后，docker tag 更改名称，就可以进行初始化操作了。
7、初始化master节点(仅在master节点上执行)
kubeadm init \
--kubernetes-version=v1.21.2 \
--service-cidr=10.96.0.0/12 \
--pod-network-cidr=10.244.0.0/16
8、初始化(仅在master节点上执行)
1、建立用户集群权限
[root@k8s-1 ~]# mkdir -p $HOME/.kube
[root@k8s-1 ~]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-1 ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config
# 如果是root用户，则可以使用：export KUBECONFIG=/etc/kubernetes/admin.conf
2、安装集群网络插件
flannel配置文件：
---
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: flannel:v0.14.0
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: flannel:v0.14.0
command:
- /opt/bin/flanneld
args:
- --ip-masq
- --kube-subnet-mgr
- --iface=eth0
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
配置文件需要修改的点：
1、image 需要修改为你的阿里云镜像服务器的地址。
2、注意你的网卡信息，是eth0还是eth1 ，需要修改。
运行Flannel：
kubectl apply -f flannel.yaml
3、将工作节点加入集群
[root@k8s-1 ~]# kubeadm token create --print-join-command
kubeadm join 192.168.31.201:6443 --token n34jwn.yzpt2nmavue5js9a --discovery-token-ca-cert-hash sha256:2384d5035a6e1c57a907f247b455fec5699c0e942d0a2e66f5092c27da7f7cb9
## 注：将上方生成的token复制到node节点上执行。
[root@k8s-1 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-1 Ready control-plane,master 13m v1.21.2
k8s-2 Ready <none> 35s v1.21.2
k8s-3 Ready <none> 39s v1.21.2
# 检查集群状态
## 第一种方式
[root@k8s-1 ~]# kubectl get nodes
# 第二种方式
[root@k8s-1 ~]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-f68b4c98f-5t7wm 1/1 Running 0 5m54s
coredns-f68b4c98f-5xqjs 1/1 Running 0 5m54s
etcd-k8s-1 1/1 Running 0 6m3s
kube-apiserver-k8s-1 1/1 Running 0 6m3s
kube-controller-manager-k8s-1 1/1 Running 0 6m3s
kube-flannel-ds-njn5h 1/1 Running 4 5m24s
kube-flannel-ds-sjtv7 1/1 Running 4 5m24s
kube-flannel-ds-vz8pn 1/1 Running 4 5m24s
kube-proxy-hsdxs 1/1 Running 5 5m54s
kube-proxy-tqhfg 1/1 Running 5 5m54s
kube-proxy-z8kqx 1/1 Running 5 5m54s
kube-scheduler-k8s-1 1/1 Running 0 6m3s
# 第三种方式：直接验证集群DNS
[root@k8s-1 ~]# kubectl run test-pod -it --rm --image=busybox:1.28.3
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes
Server: 10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local
Name: kubernetes
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local
9、kubectl命令补全
yum install -y bash-completion
source /usr/share/bash-completion/bash_completion
source <(kubectl completion bash)
echo "source <(kubectl completion bash)" >> ~/.bashrc
