k8s集群搭建
- minikube
只是一个 K8S 集群模拟器，只有一个节点的集群，只为测试用，master 和 worker 都在一起。 - 裸机安装
至少需要两台机器（主节点、工作节点个一台），需要自己安装 Kubernetes 组件，配置会稍微麻烦点。
缺点：配置麻烦，缺少生态支持，例如负载均衡器、云存储。 - 直接用云平台 Kubernetes
可视化搭建，只需简单几步就可以创建好一个集群。
优点：安装简单，生态齐全，负载均衡器、存储等都给你配套好，简单操作就搞定
腾讯云平台容器服务链接：https://cloud.tencent.com/act/cps/redirect?redirect=10058&cps_key=114d98136b019ef3d1d919d8ecadb3b7 - k3s
安装简单，脚本自动完成。
优点：轻量级，配置要求低，安装简单，生态齐全。
链接：https://k3s.io/
法一：1 minikube
可直接利用Docker Desktop搭建
法二：2 裸机安装
0 环境准备
- 节点数量: 3 台虚拟机 centos7
- 硬件配置: 2G或更多的RAM，2个CPU或更多的CPU，硬盘至少30G 以上
- 网络要求: 多个节点之间网络互通，每个节点能访问外网
1 集群规划
- k8s-node1：10.15.0.5
- k8s-node2：10.15.0.6
- k8s-node3：10.15.0.7
2 设置主机名
$ hostnamectl set-hostname k8s-node1
$ hostnamectl set-hostname k8s-node2
$ hostnamectl set-hostname k8s-node3
3 同步 hosts 文件
如果 DNS 不支持主机名称解析，还需要在每台机器的
/etc/hosts文件中添加主机名和 IP 的对应关系：
cat >> /etc/hosts <<EOF
10.15.0.5 k8s-node1
10.15.0.6 k8s-node2
10.15.0.7 k8s-node3
EOF
4 关闭防火墙
$ systemctl stop firewalld && systemctl disable firewalld
5 关闭 SELINUX
注意: ARM 架构请勿执行,执行会出现 ip 无法获取问题!
$ setenforce 0 && sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
6 关闭 swap 分区
$ swapoff -a && sed -ri 's/.*swap.*/#&/' /etc/fstab
7 同步时间
$ yum install ntpdate -y
$ ntpdate time.windows.com
8 安装 containerd
# 安装 yum-config-manager 相关依赖
$ yum install -y yum-utils device-mapper-persistent-data lvm2
# 添加 containerd yum 源
$ yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
# 安装 containerd
$ yum install -y containerd.io cri-tools
# 配置 containerd
$ cat > /etc/containerd/config.toml <<EOF
disabled_plugins = ["restart"]
[plugins.linux]
shim_debug = true
[plugins.cri.registry.mirrors."docker.io"]
endpoint = ["https://frz7i079.mirror.aliyuncs.com"]
[plugins.cri]
sandbox_image = "registry.aliyuncs.com/google_containers/pause:3.2"
EOF
# 启动 containerd 服务 并 开机配置自启动
$ systemctl enable containerd && systemctl start containerd && systemctl status containerd
# 配置 containerd 配置
$ cat > /etc/modules-load.d/containerd.conf <<EOF
overlay
br_netfilter
EOF
# 配置 k8s 网络配置
$ cat > /etc/sysctl.d/k8s.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
# 加载 overlay br_netfilter 模块
$ modprobe overlay
$ modprobe br_netfilter
# 查看当前配置是否生效
$ sysctl -p /etc/sysctl.d/k8s.conf
9 添加源
- 查看源
$ yum repolist
- 添加源 x86
$ cat <<EOF > kubernetes.repo
[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
$ mv kubernetes.repo /etc/yum.repos.d/
- 添加源 ARM
$ cat << EOF > kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-aarch64
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
$ mv kubernetes.repo /etc/yum.repos.d/
11 安装 k8s
# 安装最新版本
$ yum install -y kubelet kubeadm kubectl
# 指定版本安装
# yum install -y kubelet-1.26.0 kubectl-1.26.0 kubeadm-1.26.0
# 启动 kubelet
$ sudo systemctl enable kubelet && sudo systemctl start kubelet && sudo systemctl status kubelet
12 初始化集群
注意: 初始化 k8s 集群仅仅需要再在 master 节点进行集群初始化!
$ kubeadm init \
--apiserver-advertise-address=10.15.0.5 \
--pod-network-cidr=10.244.0.0/16 \
--image-repository registry.aliyuncs.com/google_containers \
--cri-socket=unix:///var/run/containerd/containerd.sock
# 添加新节点
$ kubeadm token create --print-join-command --ttl=0
$ kubeadm join 10.15.0.21:6443 --token xjm7ts.gu3ojvta6se26q8i --discovery-token-ca-cert-hash sha256:14c8ac5c04ff9dda389e7c6c505728ac1293c6aed5978c3ea9c6953d4a79ed34
13 配置集群网络
创建配置: kube-flannel.yml ,执行 kubectl apply -f kube-flannel.yml
注意: 只在主节点执行即可!
---
kind: Namespace
apiVersion: v1
metadata:
name: kube-flannel
labels:
pod-security.kubernetes.io/enforce: privileged
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: flannel
rules:
- apiGroups:
- ""
resources:
- pods
verbs:
- get
- apiGroups:
- ""
resources:
- nodes
verbs:
- get
- 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-flannel
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: flannel
namespace: kube-flannel
---
kind: ConfigMap
apiVersion: v1
metadata:
name: kube-flannel-cfg
namespace: kube-flannel
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-flannel
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-plugin
#image: flannelcni/flannel-cni-plugin:v1.1.0 for ppc64le and mips64le (dockerhub limitations may apply)
image: docker.io/rancher/mirrored-flannelcni-flannel-cni-plugin:v1.1.0
command:
- cp
args:
- -f
- /flannel
- /opt/cni/bin/flannel
volumeMounts:
- name: cni-plugin
mountPath: /opt/cni/bin
- name: install-cni
#image: flannelcni/flannel:v0.20.2 for ppc64le and mips64le (dockerhub limitations may apply)
image: docker.io/rancher/mirrored-flannelcni-flannel:v0.20.2
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: flannelcni/flannel:v0.20.2 for ppc64le and mips64le (dockerhub limitations may apply)
image: docker.io/rancher/mirrored-flannelcni-flannel:v0.20.2
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
- name: EVENT_QUEUE_DEPTH
value: "5000"
volumeMounts:
- name: run
mountPath: /run/flannel
- name: flannel-cfg
mountPath: /etc/kube-flannel/
- name: xtables-lock
mountPath: /run/xtables.lock
volumes:
- name: run
hostPath:
path: /run/flannel
- name: cni-plugin
hostPath:
path: /opt/cni/bin
- name: cni
hostPath:
path: /etc/cni/net.d
- name: flannel-cfg
configMap:
name: kube-flannel-cfg
- name: xtables-lock
hostPath:
path: /run/xtables.lock
type: FileOrCreate
14 查看集群状态
# 查看集群节点状态 全部为 Ready 代表集群搭建成功
$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-node1 Ready control-plane 21h v1.26.0
k8s-node2 Ready <none> 21h v1.26.0
k8s-node3 Ready <none> 21h v1.26.0
# 查看集群系统 pod 运行情况,下面所有 pod 状态为 Running 代表集群可用
$ kubectl get pod -A
NAMESPACE NAME READY STATUS RESTARTS AGE
default nginx 1/1 Running 0 21h
kube-flannel kube-flannel-ds-gtq49 1/1 Running 0 21h
kube-flannel kube-flannel-ds-qpdl6 1/1 Running 0 21h
kube-flannel kube-flannel-ds-ttxjb 1/1 Running 0 21h
kube-system coredns-5bbd96d687-p7q2x 1/1 Running 0 21h
kube-system coredns-5bbd96d687-rzcnz 1/1 Running 0 21h
kube-system etcd-k8s-node1 1/1 Running 0 21h
kube-system kube-apiserver-k8s-node1 1/1 Running 0 21h
kube-system kube-controller-manager-k8s-node1 1/1 Running 0 21h
kube-system kube-proxy-mtsbp 1/1 Running 0 21h
kube-system kube-proxy-v2jfs 1/1 Running 0 21h
kube-system kube-proxy-x6vhn 1/1 Running 0 21h
kube-system kube-scheduler-k8s-node1 1/1 Running 0 21h
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