一、安装环境说明
硬件要求
内存:2GB或更多RAM
CPU: 2核CPU或更多CPU
硬盘: 30GB或更多
本次环境说明:
操作系统:CentOS 7.6
master: 192.168.7.111
node01: 192.168.7.112
node02: 192.168.7.113
二、环境准备
注:所有K8S服务器节点都需执行
1.关闭防火墙和selinux
关闭防火墙
systemctl stop firewalld && systemctl disable firewalld && iptables -F
关闭selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config && setenforce 0
2. 关闭swap分区
临时关闭
swapoff -a
永久关闭swap
sed -ri 's/.*swap.*/#&/' /etc/fstab
3.修改hosts文件
设置主机名(不设置也可以,但是要保证主机名不相同)
master节点
hostnamectl set-hostname k8s-master #此为示例,可自定义主机名
node1节点
hostnamectl set-hostname k8s-node1 #此为示例,可自定义主机名
node2节点
hostnamectl set-hostname k8s-node2 #此为示例,可自定义主机名
修改本地hosts文件,每个节点都需要配hosts
vi /etc/hosts 添加如下内容
192.168.7.111 k8s-master
192.168.7.112 k8s-node1
192.168.7.113 k8s-node2
4.修改内核参数
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
sysctl --system
5.加载ip_vs内核模块
如果kube-proxy 模式为ip_vs则必须加载,本文采用iptables
modprobe ip_vs
modprobe ip_vs_rr
modprobe ip_vs_wrr
modprobe ip_vs_sh
modprobe nf_conntrack_ipv4
设置下次开机自动加载
cat > /etc/modules-load.d/ip_vs.conf << EOF
ip_vs
ip_vs_rr
ip_vs_wrr
ip_vs_sh
nf_conntrack_ipv4
EOF
三、安装docker
1.配置yum源(这里使用阿里云的源)
yum install wget -y
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
2. 安装docker
安装指定版本的docker
列出所有docker版本:
yum list docker-ce.x86_64 --showduplicates | sort
选择一个你想要的版本进行安装,这里安装docker 19.03.9版本
yum -y install docker-ce-19.03.9-3.el7 docker-ce-cli-19.03.9-3.el7
3.编辑docker配置文件
mkdir /etc/docker/
cat > /etc/docker/daemon.json << EOF
{
"registry-mirrors": ["https://gqs7xcfd.mirror.aliyuncs.com","https://hub-mirror.c.163.com"],
"exec-opts": ["native.cgroupdriver=systemd"],
"log-driver": "json-file",
"log-opts": {
"max-size": "100m"
},
"storage-driver": "overlay2"
}
EOF
4.启动docker服务
systemctl daemon-reload && systemctl enable docker && systemctl start docker
四、安装kubeadm,kubelet和kubectl
1.配置yum源(这里使用阿里云的源)
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=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
2.安装指定版本的kubeadm,kubelet,kubectl
yum install -y kubelet-1.18.8 kubeadm-1.18.8 kubectl-1.18.8
指定其他版本也可照做,只需指定相应的版本即可,比如安装 1.16.9
yum install -y kubelet-1.15.7 kubeadm-1.15.7 kubectl-1.15.7
列出所有版本
yum list kubelet --showduplicates
3.设置开机自启
systemctl enable kubelet
五、部署Kubernetes Master节点
1.master节点初始化,master节点上执行:
kubeadm init \
--kubernetes-version 1.18.8 \
--apiserver-advertise-address=0.0.0.0 \
--service-cidr=10.96.0.0/16 \
--pod-network-cidr=10.245.0.0/16 \
--image-repository registry.aliyuncs.com/google_containers
注意点:
版本必须和上边安装的kubelet,kubead,kubectl保持一致
参数说明
--kubernetes-version v1.18.8 #指定版本
--apiserver-advertise-address #为通告给其它组件的IP,一般应为master节点的IP地址
--service-cidr #指定service网络,不能和node网络冲突
--pod-network-cidr #指定pod网络,不能和node网络、service网络冲突
--image-repository registry.aliyuncs.com/google_containers #指定镜像源,由于默认拉取镜像地址k8s.gcr.io国内无法访问,这里指定阿里云镜像仓库地址。如果k8s版本比较新,可能阿里云没有对应的镜像,就需要自己从其它地方获取镜像了。
--control-plane-endpoint #标志应该被设置成负载均衡器的地址或 DNS 和端口(可选)
2.等待拉取镜像
也可用自己提前给各个节点拉取镜像 ,查看所需镜像命令:
kubeadm --kubernetes-version 1.18.8 config images list
等待镜像拉取成功后,会继续初始化集群,等到初始化完成后,会看到类似如下信息,保留最后两行的输出后边会用到;
3. 配置kubectl
就是执行初始化成功后输出的那三条命令;
mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config
4.查看节点信息
kubectl get nodes
六、node节点加入集群
各个node节点也要进行 二三四步骤的操作,然后才能加入集群
1.node1、node2加入集群,node节点执行
kubeadm join 192.168.7.111:6443 --token 1quyaw.xa7yel3xla129kfw \
--discovery-token-ca-cert-hash sha256:470410e1180b119ebe8ee3ae2842e7a4a852e590896306ec0dab26b168d99197
2. master节点上查看集群节点
kubectl get nodes
可以看到 STATUS状态都是NotReady, 这是因为确实网络插件导致的,等安装好网络插件就好了
七、安装插件
1.安装 flannel
从官网下载yaml文件
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
也可从这里直接复制:
---
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": "10.245.0.0/16",
"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:v0.14.0
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: quay.io/coreos/flannel:v0.14.0
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
更改 128行的网络配置,要和 pod-network-cidr保持一致
然后执行yaml文件:
kubectl apply -f kube-flannel.yaml
2.查看flannel部署结果
kubectl -n kube-system get pods -o wide
3.查看各个node的状态
kubectl get nodes
4. 修改集群kube-proxy的模式为iptables
由于 k8s 1.18对内核版本要求比较高,3.10的内核部署1.18.8使用ipvs模式会存在coredns无法解析等问题。股在此采用iptables模式。 如果你服务内核4+起,则采用iptables 和ipvs均可。
kubectl get cm kube-proxy -n kube-system -o yaml | sed 's/mode: ""/mode: "iptables"/' | kubectl apply -f -
kubectl -n kube-system rollout restart daemonsets.apps kube-proxy
kubectl -n kube-system rollout restart daemonsets.apps kube-flannel-ds