kubernetes 高可用的配置

kubernetes 高可用的配置

標籤（空格分隔）： kubernetes系列

---

一：kubernetes 高可用的配置

一：kubernetes 的 kubeadmn高可用的配置

---

二： 系統初始化

2.1 系統主機名

192.168.100.11  node01.flyfish
192.168.100.12  node02.flyfish
192.168.100.13  node03.flyfish
192.168.100.14  node04.flyfish
192.168.100.15  node05.flyfish
192.168.100.16  node06.flyfish
192.168.100.17  node07.flyfish

----

node01.flyfish / node02.flyfish /node03.flyfish  作爲master 節點

node04.flyfish / node05.flyfish / node06.flyfish 作爲work節點

node07.flyfish  作爲 測試節點

keepalive集羣VIP 地址爲： 192.168.100.100

---

2.2 關閉firewalld 清空iptables 與 selinux 規則

系統節點全部執行：

systemctl stop firewalld && systemctl disable firewalld && yum -y install iptables-services && systemctl start iptables && systemctl enable iptables && iptables -F && service iptables save

關閉 SELINUX與swap 內存

swapoff -a && sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

setenforce 0 && sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config

---

2.3 安裝 依賴包

全部節點安裝

yum install -y conntrack ntpdate ntp ipvsadm ipset jq iptables curl sysstat libseccomp wget vim net-tools git

2.4升級調整內核參數，對於 K8S

所有節點都執行

cat > kubernetes.conf <<EOF

net.bridge.bridge-nf-call-iptables=1 
net.bridge.bridge-nf-call-ip6tables=1 
net.ipv4.ip_forward=1 
net.ipv4.tcp_tw_recycle=0 
vm.swappiness=0 # 禁止使用 swap 空間，只有當系統 OOM 時才允許使用它 vm.overcommit_memory=1 # 不檢查物理內存是否夠用 
vm.panic_on_oom=0 # 開啓 OOM 
fs.inotify.max_user_instances=8192 
fs.inotify.max_user_watches=1048576 
fs.file-max=52706963 
fs.nr_open=52706963 
net.ipv6.conf.all.disable_ipv6=1 
net.netfilter.nf_conntrack_max=2310720

EOF 

cp kubernetes.conf /etc/sysctl.d/kubernetes.conf 
sysctl -p /etc/sysctl.d/kubernetes.conf

2.5 調整系統時區

# 設置系統時區爲 中國/上海 timedatectl set-timezone Asia/Shanghai 
# 將當前的 UTC 時間寫入硬件時鐘 timedatectl set-local-rtc 0 
# 重啓依賴於系統時間的服務 
systemctl restart rsyslog && systemctl restart crond

關閉系統不需要的服務
systemctl stop postfix && systemctl disable postfix

2.6 設置 rsyslogd 和 systemd journald

系統全部節點

mkdir /var/log/journal # 持久化保存日誌的目錄 
mkdir /etc/systemd/journald.conf.d 
cat > /etc/systemd/journald.conf.d/99-prophet.conf <<EOF

[Journal]
# 持久化保存到磁盤 
Storage=persistent 
# 壓縮歷史日誌 
Compress=yes 
SyncIntervalSec=5m 
RateLimitInterval=30s 
RateLimitBurst=1000 
# 最大佔用空間 10G 
SystemMaxUse=10G 
# 單日誌文件最大 200M 
SystemMaxFileSize=200M 
# 日誌保存時間 2 周 
MaxRetentionSec=2week 
# 不將日誌轉發到 syslog 
ForwardToSyslog=no 

EOF 

systemctl restart systemd-journald

2.7升級系統內核爲 4.44

CentOS 7.x 系統自帶的 3.10.x 內核存在一些 Bugs，導致運行的 Docker、Kubernetes 不穩定，例如： rpm -Uvh
http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm

rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm 
# 安裝完成後檢查 /boot/grub2/grub.cfg 中對應內核 menuentry 中是否包含 initrd16 配置，如果沒有，再安裝 一次！ 
yum --enablerepo=elrepo-kernel install -y kernel-lt 
# 設置開機從新內核啓動 
grub2-set-default "CentOS Linux (4.4.182-1.el7.elrepo.x86_64) 7 (Core)" 

reboot
# 重啓後安裝內核源文件 
yum --enablerepo=elrepo-kernel install kernel-lt-devel-$(uname -r) kernel-lt-headers-$(uname -r)

2.8 kube-proxy開啓ipvs的前置條件

modprobe br_netfilter 

cat > /etc/sysconfig/modules/ipvs.modules <<EOF 

#!/bin/bash 
modprobe -- ip_vs 
modprobe -- ip_vs_rr 
modprobe -- ip_vs_wrr 
modprobe -- ip_vs_sh 
modprobe -- nf_conntrack_ipv4 
EOF 

chmod 755 /etc/sysconfig/modules/ipvs.modules 

bash /etc/sysconfig/modules/ipvs.modules 

lsmod | grep -e ip_vs -e nf_conntrack_ipv4

---

三： 開始安裝docker

3.1 安裝docker

機器節點都執行：

yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo 

yum update -y && yum install docker-ce-18.09.9 docker-ce-cli-18.09.9 containerd.io -y 

重啓機器： reboot 

查看內核版本： uname -r 

在加載： grub2-set-default "CentOS Linux (4.4.182-1.el7.elrepo.x86_64) 7 (Core)"  && reboot
如果還不行 
就改 文件 ： vim /etc/grub2.cfg  註釋掉 3.10 的 內核

保證 內核的版本 爲 4.4 

service docker start 
chkconfig docker on 

## 創建 /etc/docker 目錄

cat > /etc/docker/daemon.json <<EOF 

{
"exec-opts": ["native.cgroupdriver=systemd"],
"log-driver": "json-file",
"log-opts": {
 "max-size": "100m"
},

"insecure-registries": ["https://node04.flyfish"],
"registry-mirrors": ["https://registry.docker-cn.com","http://hub-mirror.c.163.com"]
}

EOF 

mkdir -p /etc/systemd/system/docker.service.d 

# 重啓docker服務 

systemctl daemon-reload && systemctl restart docker && systemctl enable docker

---

安裝命令補全工具
yum -y install bash-completion

source /etc/profile.d/bash_completion.sh

鏡像加速

由於Docker Hub的服務器在國外，下載鏡像會比較慢，可以配置鏡像加速器。主要的加速器有：Docker官方提供的中國registry mirror、阿里雲加速器、DaoCloud 加速器，本文以阿里加速器配置爲例。

登陸阿里雲容器模塊:

登陸地址爲：https://cr.console.aliyun.com ,未註冊的可以先註冊阿里雲賬戶

 mkdir /etc/docker

 tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://dfmo7maf.mirror.aliyuncs.com"]
}
EOF

Cgroup Driver:

修改daemon.json
修改daemon.json，新增‘"exec-opts": ["native.cgroupdriver=systemd"]
cat /etc/docker/daemon.json

{
  "registry-mirrors": ["https://dfmo7maf.mirror.aliyuncs.com"],
   "exec-opts": ["native.cgroupdriver=systemd"]
}

修改cgroupdriver是爲了消除告警：
[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/

重新加載docker
systemctl daemon-reload
systemctl restart docker

四：安裝keepalived

control plane節點都執行本部分操作。
安裝keepalived

yum install -y keepalived 

keepalived配置

node01.flyfish 配置：
cat /etc/keepalived/keepalived.conf
---
! Configuration File for keepalived
global_defs {
   router_id node01.flyfish
}
vrrp_instance VI_1 {
    state MASTER 
    interface ens33
    virtual_router_id 50
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.100.100
    }
}

---

node02.flyfish 配置:
cat /etc/keepalived/keepalived.conf
---
! Configuration File for keepalived
global_defs {
   router_id node02.flyfish
}
vrrp_instance VI_1 {
    state BACKUP 
    interface ens33
    virtual_router_id 50
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.100.100
    }
}

---

node03.flyfish 配置
cat /etc/keepalived/keepalived.conf
---
! Configuration File for keepalived
global_defs {
   router_id node03.flyfish
}
vrrp_instance VI_1 {
    state BACKUP 
    interface ens33
    virtual_router_id 50
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.100.100
    }
}
---

所有control plane啓動keepalived服務並設置開機啓動
service keepalived start

systemctl enable keepalived

vip在node01.flyfish上

---

五： k8s安裝

5.1:安裝 Kubeadm （主從配置）

control plane和work節點都執行本部分操作。

cat >> /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes] 
name=Kubernetes 
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64 
enabled=1 
gpgcheck=0 
repo_gpgcheck=0 
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg 
http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg 
EOF

---

yum list kubelet --showduplicates | sort -r

本文安裝的kubelet版本是1.16.4，該版本支持的docker版本爲1.13.1, 17.03, 17.06, 17.09, 18.06, 18.09。

yum -y install kubeadm-1.16.4 kubectl-1.16.4 kubelet-1.16.4

---
kubelet 運行在集羣所有節點上，用於啓動Pod和容器等對象的工具
kubeadm 用於初始化集羣，啓動集羣的命令工具
kubectl 用於和集羣通信的命令行，通過kubectl可以部署和管理應用，查看各種資源，創建、刪除和更新各種組件
---
啓動kubelet:

systemctl enable kubelet && systemctl start kubelet

kubectl命令補全
echo "source <(kubectl completion bash)" >> ~/.bash_profile
source .bash_profile

5.2 下載鏡像

鏡像下載的腳本:

Kubernetes幾乎所有的安裝組件和Docker鏡像都放在goolge自己的網站上,直接訪問可能會有網絡問題，這裏的解決辦法是從阿里雲鏡像倉庫下載鏡像，拉取到本地以後改回默認的鏡像tag。本文通過運行image.sh腳本方式拉取鏡像。

---

下載腳本
vim image.sh 
---
#!/bin/bash

url=registry.cn-hangzhou.aliyuncs.com/loong576

version=v1.16.4

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

---
./image.sh 

docker images 

node01.flyfish 節點 初始化

cat kubeadm-config.yaml
---
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
kubernetesVersion: v1.16.4
apiServer:
  certSANs:    #填寫所有kube-apiserver節點的hostname、IP、VIP
  - node01.flyfish
  - node02.flyfish
  - node03.flyfish
  - node04.flyfish
  - node05.flyfish
  - node06.flyfish
  - 192.168.100.11
  - 192.168.100.12
  - 192.168.100.13
  - 192.168.100.14
  - 192.168.100.15
  - 192.168.100.16
  - 192.168.100.100
controlPlaneEndpoint: "192.168.100.100:6443"
networking:
  podSubnet: "10.244.0.0/16"
---

---

初始化主機節點：

kubeadm init --config=kubeadm-config.yaml

---
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

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/

You can now join any number of control-plane nodes by copying certificate authorities 
and service account keys on each node and then running the following as root:

  kubeadm join 192.168.100.100:6443 --token 3j4th7.4va6qsj7at7ky2qs \
    --discovery-token-ca-cert-hash sha256:13d17c476688e4e78837b9cac94efa7edf689bf530a2120e2b81bf13b588fff9 \
    --control-plane       

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 192.168.100.100:6443 --token 3j4th7.4va6qsj7at7ky2qs \
    --discovery-token-ca-cert-hash sha256:13d17c476688e4e78837b9cac94efa7edf689bf530a2120e2b81bf13b588fff9 
---

如果初始化失敗，可執行kubeadm reset後重新初始化

kubeadm reset
rm -rf $HOME/.kube/config

---

加載環境變量
echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile

source .bash_profile

本文所有操作都在root用戶下執行，若爲非root用戶，則執行如下操作：

mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config

---

安裝flannel網絡
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/2140ac876ef134e0ed5af15c65e414cf26827915/Documentation/kube-flannel.yml

kubectl apply -f kube-flannel.yml

kubectl get pod -n kube-system 

---

5.3 control plane節點加入集羣

證書分發
在node01.flyfish 上面執行 腳本：cert-main-master.sh
vim cert-main-master.sh
---
#!/bin/bash

USER=root # customizable
CONTROL_PLANE_IPS="192.168.100.12 192.168.100.13"
for host in ${CONTROL_PLANE_IPS}; do
    scp /etc/kubernetes/pki/ca.crt "${USER}"@$host:
    scp /etc/kubernetes/pki/ca.key "${USER}"@$host:
    scp /etc/kubernetes/pki/sa.key "${USER}"@$host:
    scp /etc/kubernetes/pki/sa.pub "${USER}"@$host:
    scp /etc/kubernetes/pki/front-proxy-ca.crt "${USER}"@$host:
    scp /etc/kubernetes/pki/front-proxy-ca.key "${USER}"@$host:
    scp /etc/kubernetes/pki/etcd/ca.crt "${USER}"@$host:etcd-ca.crt
    # Quote this line if you are using external etcd
    scp /etc/kubernetes/pki/etcd/ca.key "${USER}"@$host:etcd-ca.key
done
---

./cert-main-master.sh

登錄 node02.flyfish

cd /root
mkdir -p /etc/kubernetes/pki

mv *.crt *.key *.pub /etc/kubernetes/pki/

cd /etc/kubernetes/pki

mkdir etcd 

mv etcd-* etcd
cd etcd
mv etcd-ca.key ca.key
mv etcd-ca.crt ca.crt

node02.flyfish 加入集羣

kubeadm join 192.168.100.100:6443 --token 3j4th7.4va6qsj7at7ky2qs \
    --discovery-token-ca-cert-hash sha256:13d17c476688e4e78837b9cac94efa7edf689bf530a2120e2b81bf13b588fff9 \
    --control-plane

---

登錄 node03.flyfish

cd /root
mkdir -p /etc/kubernetes/pki

mv *.crt *.key *.pub /etc/kubernetes/pki/

cd /etc/kubernetes/pki

mkdir etcd 

mv etcd-* etcd
cd etcd
mv etcd-ca.key ca.key
mv etcd-ca.crt ca.crt

node03.flyfish 加入集羣

kubeadm join 192.168.100.100:6443 --token 3j4th7.4va6qsj7at7ky2qs \
    --discovery-token-ca-cert-hash sha256:13d17c476688e4e78837b9cac94efa7edf689bf530a2120e2b81bf13b588fff9 \
    --control-plane

node02.flyfish 與node03.flyfis 加載 環境變量

rsync -avrzP [email protected]:/etc/kubernetes/admin.conf /etc/kubernetes/

echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile

source .bash_profile

---

查看節點
kubectl get node 

kubectl get pod -o wide -n kube-system

---

5.4 將從節點加入集羣

node04.flyfish 加入 集羣

kubeadm join 192.168.100.100:6443 --token 3j4th7.4va6qsj7at7ky2qs \
    --discovery-token-ca-cert-hash sha256:13d17c476688e4e78837b9cac94efa7edf689bf530a2120e2b81bf13b588fff9 

---

node05.flyfish 加入集羣

kubeadm join 192.168.100.100:6443 --token 3j4th7.4va6qsj7at7ky2qs \
    --discovery-token-ca-cert-hash sha256:13d17c476688e4e78837b9cac94efa7edf689bf530a2120e2b81bf13b588fff9

node06.flyfish 加入集羣

kubeadm join 192.168.100.100:6443 --token 3j4th7.4va6qsj7at7ky2qs \
    --discovery-token-ca-cert-hash sha256:13d17c476688e4e78837b9cac94efa7edf689bf530a2120e2b81bf13b588fff9

---

kubectl get node 

kubectl get pods -o wide -n kube-system

5.5 在node07.flyfish 上面進行測試

登錄 node07.flyfish 

設置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 install -y kubectl-1.16.4

命令補全：

yum install -y bash-completion
source /etc/profile.d/bash_completion.sh

---

拷貝admin.conf

mkdir -p /etc/kubernetes
scp [email protected]:/etc/kubernetes/admin.conf /etc/kubernetes/
echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile
source .bash_profile

查看測試：

kubectl get nodes
kubectl get pod -n kube-system 

5.6部署dashboard 界面

注：在node07.flyfish節點上進行如下操作

1.創建Dashboard的yaml文件

wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta8/aio/deploy/recommended.yaml

sed -i 's/kubernetesui/registry.cn-hangzhou.aliyuncs.com\/loong576/g' recommended.yaml

sed -i '/targetPort: 8443/a\ \ \ \ \ \ nodePort: 30001\n\ \ type: NodePort' recommended.yaml

新增管理員帳號

vim recommended.yaml

到最後加上：
---
---

apiVersion: v1
kind: ServiceAccount
metadata:
  name: dashboard-admin
  namespace: kubernetes-dashboard
---

apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: dashboard-admin
subjects:
- kind: ServiceAccount
  name: dashboard-admin
  namespace: kubernetes-dashboard
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin

---

部署Dashboard

kubectl apply -f recommended.yaml

創建完成後，檢查相關服務運行狀態

kubectl get all -n kubernetes-dashboard 

kubectl get svc -n kubernetes-dashboard

netstat -ntlp|grep 30001

在瀏覽器輸入Dashboard訪問地址：

https://192.168.100.11:30001

授權令牌

kubectl describe secrets -n kubernetes-dashboard dashboard-admin

----

---

新建一個pod
----
vim nignx.yaml

apiVersion: apps/v1             #描述文件遵循extensions/v1beta1版本的Kubernetes API
kind: Deployment                #創建資源類型爲Deployment
metadata:                       #該資源元數據
  name: nginx-master            #Deployment名稱
spec:                           #Deployment的規格說明
  selector:
    matchLabels:
      app: nginx
  replicas: 3                   #指定副本數爲3
  template:                     #定義Pod的模板
    metadata:                   #定義Pod的元數據
      labels:                   #定義label（標籤）
        app: nginx              #label的key和value分別爲app和nginx
    spec:                       #Pod的規格說明
      containers:
      - name: nginx             #容器的名稱
        image: nginx:latest     #創建容器所使用的鏡像
----

kubectl apply -f nginx.yaml

kubectl get pod