Kubernetes 之 LoadBalancer
定义
负载均衡器 (LoadBalancer) 是 Kubernetes 中用来对外暴露 Service 服务的，它可以将服务集中到一个公共 IP 上。我们常用 MetalLB 作为自建均衡器。
使用
安装 MetalLB
kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.14.7/config/manifests/metallb-native.yaml
配置 ARP IP 池
apiVersion: metallb.io/v1beta1
kind: IPAddressPool
metadata:name: first-poolnamespace: metallb-system
spec:addresses:- 192.168.31.70-192.168.31.90
kubectl apply -f metalb-ips.yml
导入新镜像statis-web-1.0.90.tar
ctr -n=k8s.io images import static-web-1.0.90.tar
// go 语言编写的 web static 镜像代码
package mainimport ("fmt""net/http""os"
)func main() {htmlContent := os.Getenv("HTML_BODY_CONTENT")if htmlContent == "" {htmlContent = "<html><body><h1>No Content Set</h1></body></html>"} else {htmlContent = "<html><body><h1>" + htmlContent + "</h1></body></html>"}http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {_, _ = fmt.Fprint(w, htmlContent)})port := ":80"fmt.Printf("Server is listening on port %s\n", port)err := http.ListenAndServe(port, nil)if err != nil {fmt.Printf("Error starting server: %v\n", err)}
}
创建测试 Deployment 和 Service
apiVersion: apps/v1
kind: Deployment
metadata:name: deployment-web-staticnamespace: defaultlabels:app: deployment-web-static
spec:replicas: 2selector:matchLabels:app: pod-web-statictemplate:metadata:labels:app: pod-web-staticspec:containers:- name: web-staticimage: static-web:1.0.90imagePullPolicy: IfNotPresentports:- containerPort: 80env:- name: HTML_BODY_CONTENTvalue: "This is a test"
---
apiVersion: v1
kind: Service
metadata:name: service-static-webnamespace: defaultlabels:app: service-static-web
spec:type: LoadBalancerports:- port: 80protocol: TCPtargetPort: 80selector:app: pod-web-static
测试
root@k8s-master1:~# kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 67d
service-static-web LoadBalancer 10.102.54.255 192.168.31.70 80:30487/TCP 3m13s
root@k8s-master1:~# curl 192.168.31.70
<html><body><h1>This is a test</h1></body></html>
