《Kubernets部署篇：Centos7.6部署单机kubernetes1.17.4》
文章目录
- 一、架构图
- 二、部署环境
- 三、环境初始化
-
- 3.1、内核升级
- 3.2、系统初始化配置
- 四、Docker部署
- 五、kubernetes部署
-
- 5.1、设置kubernetes源
- 5.2、安装kubelet、kubeadm和kubectl
- 5.3、k8s相关镜像下载
- 5.4、kubeadm初始化master节点
- 5.5、配置kubectl
- 5.6、配置flannel网络
- 5.7、将master标记为可调度
- 5.8、kubelet服务启动
- 总结：整理不易，如果对你有帮助，可否点赞关注一下？
一、架构图
二、部署环境
操作系统：centos7.6.1810
内核版本：5.4.13
说明：建议操作系统选择centos7.5或centos7.6，centos7.2，centos7.3,centos7.4版本存在一定几率的kubelet无法启动问题。
三、环境初始化
3.1、内核升级
说明：centos7.6系统内核默认是3.10.0，这里建议内核版本为5.11.16。
内核选择：
kernel-lt（lt=long-term）长期有效
kernel-ml（ml=mainline） 主流版本
升级步骤如下：
# 1、下载内核
CSDN下载地址：https://download.csdn.net/download/m0_37814112/17047556
wget https://elrepo.org/linux/kernel/el7/x86_64/RPMS/kernel-ml-5.11.16-1.el7.elrepo.x86_64.rpm
# 2、安装内核
yum localinstall kernel-ml-5.11.16-1.el7.elrepo.x86_64.rpm -y
# 3、查看当前内核版本
grub2-editenv list
# 4、查看所有内核启动grub2
awk -F \' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg
# 5、修改为最新的内核启动
grub2-set-default 'CentOS Linux (5.11.16-1.el7.elrepo.x86_64) 7 (Core)'
# 6、再次查看内核版本
grub2-editenv list
# 7、reboot重启服务器
3.2、系统初始化配置
# 1、修改主机名
hostnamectl set-hostname k8s-master
# 2、内核参数修改
cat > /etc/sysctl.d/k8s.conf <<EOF
vm.swappiness = 0
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-arptables = 1
EOF
sysctl --system
# 3、永久新增br_netfilter模块
# k8s网络使用flannel，该网络需要设置内核参数bridge-nf-call-iptables=1，修改这个参数需要系统有br_netfilter模块。
cat > /etc/rc.sysinit << EOF
#!/bin/bash
for file in /etc/sysconfig/modules/*.modules ; do
[ -x $file ] && $file
done
EOF
cat > /etc/sysconfig/modules/br_netfilter.modules << EOF
modprobe br_netfilter
EOF
chmod 755 /etc/sysconfig/modules/br_netfilter.modules
# 4、关闭防火墙
systemctl stop firewalld && systemctl disable firewalld
# 5、永久关闭selinux
sed -i 's#SELINUX=enforcing#SELINUX=disabled#g' /etc/sysconfig/selinux
sed -i 's#SELINUX=enforcing#SELINUX=disabled#g' /etc/selinux/config
# 6、关闭swap
swapoff -a && sed -i 's/.*swap.*/#&/' /etc/fstab
# 7、安装ipvsadm
yum install ipvsadm -y
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 --color ip_vs >/dev/null
lsmod | grep ip_vs
# 8、修改文件描述符和进程数（根据实际情况修改）
vim /etc/security/limits.conf
root soft nofile 65535
root hard nofile 65535
root soft nproc 65535
root hard nproc 65535
root soft memlock unlimited
root hard memlock unlimited
* soft nofile 65535
* hard nofile 65535
* soft nproc 65535
* hard nproc 65535
* soft memlock unlimited
* hard memlock unlimited
# 9、reboot重启服务器（必须）
如下图所示：
四、Docker部署
# 1、安装依赖包
yum install yum-utils device-mapper-persistent-data lvm2 -y
# 2、设置Docker源
yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
或
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
# 3、docker安装版本查看
yum list docker-ce --showduplicates | sort -r
# 4、指定安装的docker版本为18.09.9
yum install docker-ce-18.09.9 docker-ce-cli-18.09.9 containerd.io -y
# 5、启动Docker
systemctl start docker && systemctl enable docker
# 6、修改Cgroup Driver
# 修改docker数据目录，默认是/var/lib/docker,建议数据目录为主机上最大磁盘空间目录或子目录
vim /etc/docker/daemon.json
{
"registry-mirrors": ["https://v16stybc.mirror.aliyuncs.com"],
"exec-opts": ["native.cgroupdriver=systemd"],
"graph": "/data/docker"
}
systemctl daemon-reload && systemctl restart docker
如下图所示：
五、kubernetes部署
5.1、设置kubernetes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
yum clean all && yum -y makecache
5.2、安装kubelet、kubeadm和kubectl
# 1、版本查看
yum list kubelet --showduplicates | sort -r
# 2、安装1.17.4版本
yum install kubelet-1.17.4 kubeadm-1.17.4 kubectl-1.17.4 -y
5.3、k8s相关镜像下载
vim get_image.sh
#!/bin/bash
url=registry.cn-hangzhou.aliyuncs.com/google_containers
version=v1.17.4
images=(`kubeadm config images list --kubernetes-version=$version|awk -F '/' '{print $2}'`)
for imagename in ${images[@]} ; do
docker pull $url/$imagename
docker tag $url/$imagename k8s.gcr.io/$imagename
docker rmi -f $url/$imagename
done
# flannel网络镜像下载
docker pull quay.io/coreos/flannel:v0.14.0-rc1
如下图所示：
5.4、kubeadm初始化master节点
# 1、创建初始化配置文件
kubeadm config print init-defaults > kubeadm-config.yaml
# 根据实际部署环境修改信息：
vim kubeadm-config.yaml
apiVersion: kubeadm.k8s.io/v1beta1
kind: ClusterConfiguration
networking:
serviceSubnet: "10.96.0.0/16" #service网段地址
podSubnet: "10.48.0.0/16" #pod网段地址
kubernetesVersion: "v1.17.4" #kubernetes版本
controlPlaneEndpoint: "192.168.1.216:6443" #apiserver地址
apiServer:
extraArgs:
authorization-mode: "Node,RBAC"
service-node-port-range: 30000-36000 #service端口范围
imageRepository: ""
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: "ipvs"
# 3、初始化master
kubeadm init --config=kubeadm-config.yaml --upload-certs --ignore-preflight-errors=all
如下图所示：
5.5、配置kubectl
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
5.6、配置flannel网络
# 1、下载官方模板文件
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
# 2、部署flannel网络
kubectl create -f kube-flannel.yml
# 3、根据实际情况修改kube-flannel.yml
vim 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": "10.48.0.0/16", #这里的网段地址需要与kubeadm-config.yaml配置文件定义的必须保持一致
"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-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: quay.io/coreos/flannel:v0.14.0-rc1
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
说明：官方模板文件只需要修改"Network": "10.48.0.0/16"这一字段，且这里的网段地址需要与kubeadm-config.yaml配置文件定义的必须保持一致。
5.7、将master标记为可调度
# 当创建单机版的k8s时，这个时候master节点是默认不允许调度pod 的，需要执行
kubectl taint nodes --all node-role.kubernetes.io/master-
5.8、kubelet服务启动
systemctl restart kubelet && systemctl enable kubelet
[root@node6 install-kubernetes]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 17m v1.17.4
说明：kubernetes单机版，就部署完成了。
下一章：《Kubernets部署篇：Centos7.6部署kubernetes1.17.4一主多从》
总结：整理不易，如果对你有帮助，可否点赞关注一下？
更多详细内容请参考：企业级K8s集群运维实战