k8s第二回之k8s叢集的安裝
阿新 • • 發佈：2020-12-20
# 1. k8s叢集的安裝
[TOC]
Kubernetes借鑑了Borg的設計理念，比如Pod、Service、Labels和單Pod單IP等。Kubernetes的整體架構跟Borg非常像，如下圖所示：
## 1、*架構:*
除了核心元件，還有一些推薦的Add-ons：
| **元件名稱** | **說明** |
| ------------------------- | :--------------------------: |
| **kube-dns** | 負責為整個叢集提供DNS服務 |
| **Ingress Controller** | 為服務提供外網入口 |
| **Heapster** | 提供資源監控 |
| **Dashboard** | 提供GUI |
| **Federation** | 提供跨可用區的叢集 |
| **Fluentd-elasticsearch** | 提供叢集日誌採集、儲存與查詢 |
## 2、環境準備
3臺主機,IP地址、主機名的host解析分別如下(最好再做一下SSH免祕鑰的登入,實驗環境方便操作!)
```
10.0.0.11 k8s-master
10.0.0.12 k8s-node-1
10.0.0.13 k8s-node-2
```
## 3、master節點安裝etcd
```shell
1. 安裝 etcd
yum install etcd -y
2. 編輯配置檔案
6行：ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
21行：ETCD_ADVERTISE_CLIENT_URLS="http://10.0.0.11:2379"
3. 啟動並自啟服務
systemctl start etcd.service
systemctl enable etcd.service
----------------------------------------------------------
etcdctl set testdir/testkey0 0
etcdctl get testdir/testkey0
etcdctl -C http://10.0.0.11:2379 cluster-health
```
*注: etcd原生支援做叢集，etcd服務可以安裝在其他伺服器做成etcd叢集,通過kubernets連線*
## 4、 master節點安裝kubernetes
```bash
1. 安裝kubernetes
yum install kubernetes-master.x86_64 -y
2. 編輯配置
vim /etc/kubernetes/apiserver
8行: KUBE_API_ADDRESS="--insecure-bind-address=0.0.0.0"
11行：KUBE_API_PORT="--port=8080"
14行: KUBELET_PORT="--kubelet-port=10250"
17行：KUBE_ETCD_SERVERS="--etcd-servers=http://10.0.0.11:2379"
23行：KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"
vim /etc/kubernetes/config
22行：KUBE_MASTER="--master=http://10.0.0.11:8080"
3. 重啟並自啟k8s
systemctl enable kube-apiserver.service
systemctl restart kube-apiserver.service
systemctl enable kube-controller-manager.service
systemctl restart kube-controller-manager.service
systemctl enable kube-scheduler.service
systemctl restart kube-scheduler.service
```
檢查服務是否安裝正常
```bash
[root@k8s-master ~]# kubectl get componentstatus
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-0 Healthy {"health":"true"}
```
## 5、node節點安裝kubernetes
```shell
#1. 安裝kubernetes-node
yum install kubernetes-node.x86_64 -y
#2. 編輯配置
vim /etc/kubernetes/config
22行：KUBE_MASTER="--master=http://10.0.0.11:8080"
vim /etc/kubernetes/kubelet
5行：KUBELET_ADDRESS="--address=0.0.0.0"
8行：KUBELET_PORT="--port=10250"
11行：KUBELET_HOSTNAME="--hostname-override=10.0.0.12"
14行：KUBELET_API_SERVER="--api-servers=http://10.0.0.11:8080"
#3. 啟動並自啟服務
systemctl enable kubelet.service
systemctl restart kubelet.service
systemctl enable kube-proxy.service
systemctl restart kube-proxy.service
systemctl enable docker
```
在master節點檢查驗證:
```bash
[root@k8s-master /etc/kubernetes ]#: kubectl get nodes
NAME STATUS AGE
10.0.0.12 Ready 2m
10.0.0.13 Ready 5s
```
## 6、所有節點配置flannel網路
flannel和overlay網路類似需要資料庫,flannel需要etcd資料庫
```bash
yum install flannel -y
sed -i 's#http://127.0.0.1:2379#http://10.0.0.11:2379#g' /etc/sysconfig/flanneld
##master節點：
etcdctl mk /atomic.io/network/config '{ "Network": "172.18.0.0/16","Backend": {"Type": "vxlan"} }'
#所有節點執行
systemctl enable flanneld.service
systemctl restart flanneld.service
##node節點：
systemctl enable flanneld.service
systemctl restart flanneld.service
systemctl restart docker
systemctl restart kubelet.service
systemctl restart kube-proxy.service
vim /usr/lib/systemd/system/docker.service
#在[Service]區域下增加一行
ExecStartPost=/usr/sbin/iptables -P FORWARD ACCEPT
systemctl daemon-reload
systemctl restart docker
```
```bash
systemd中有這樣功能的配置:
1) ExexStart
2) ExexStartPost
```
最後在master節點驗證結果如下:
## 7、配置master為映象倉庫
```shell
#所有節點執行
##1. 配置映象加速
vi /etc/docker/daemon.json
{
"registry-mirrors": ["https://registry.docker-cn.com"],
"insecure-registries": ["10.0.0.11:5000"]
}
##2. 過載docker
systemctl restart docker
#master節點
yum install docker -y
systemctl enable docker
systemctl start docker
docker run -d -p 5000:5000 --restart=always --name registry -v /opt/myregistry:/var/lib/registry regis