Ingress是Kubernetes一个非常重要的Controller,它类似一个路由转发的组件,可以让外界访问Kubernetes内部的Service。除了Ingress,还有NodePort、LoadBalance等方式,Ingress暴露给外界的方式还是很常用的。
Ingress
Kubernetes
Controller
Service
NodePort
LoadBalance
我们通过helm来安装,会方便一些,先更新helm的仓库。
helm
$ helm repo update
Helm相关文章:用Helm部署Kubernetes应用,支持多环境部署与版本回滚
Helm
容器技术相关文章
更新完之后,查找仓库关于Ingress的包有哪些:
$ $ helm search repo ingress NAME CHART VERSION APP VERSION DESCRIPTION azure/gce-ingress 1.2.0 1.4.0 A GCE Ingress Controller azure/ingressmonitorcontroller 1.0.48 1.0.47 IngressMonitorController chart that runs on kub... azure/nginx-ingress 1.41.2 v0.34.1 An nginx Ingress controller that uses ConfigMap... stable/nginx-ingress 0.9.5 0.10.2 An nginx Ingress controller that uses ConfigMap... azure/contour 0.2.0 v0.15.0 Contour Ingress controller for Kubernetes azure/external-dns 1.8.0 0.5.14 Configure external DNS servers (AWS Route53, Go... azure/kong 0.36.7 1.4 DEPRECATED The Cloud-Native Ingress and API-man... azure/lamp 1.1.3 7 Modular and transparent LAMP stack chart suppor... azure/nginx-lego 0.3.1 Chart for nginx-ingress-controller and kube-lego azure/traefik 1.87.2 1.7.24 A Traefik based Kubernetes ingress controller w... azure/voyager 3.2.4 6.0.0 DEPRECATED Voyager by AppsCode - Secure Ingress... stable/external-dns 0.4.9 0.4.8 Configure external DNS servers (AWS Route53, Go... stable/lamp 0.1.4 Modular and transparent LAMP stack chart suppor... stable/nginx-lego 0.3.1 Chart for nginx-ingress-controller and kube-lego stable/traefik 1.24.1 1.5.3 A Traefik based Kubernetes ingress controller w... stable/voyager 3.1.0 6.0.0-rc.0 Voyager by AppsCode - Secure Ingress Controller...
选择azure/nginx-ingress来安装,注意是有版本的。安装如下:
azure/nginx-ingress
$ helm install pkslow-ingress azure/nginx-ingress
安装成功后,控制台会有输出相关的使用说明。但要注意的是,要去Kubernetes Dashboard查看一下是否真的安装成功。我安装遇到过失败,原因都是因为镜像下载失败。解决方案是打开全局代理,先手动下载好相关镜像。如:
Kubernetes Dashboard
代理
us.gcr.io/k8s-artifacts-prod/ingress-nginx/controller:v0.34.1 k8s.gcr.io/defaultbackend-amd64:1.5 jettech/kube-webhook-certgen:v1.0.0 quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.32.0
之后就安装成功了,相关的Pods都跑起来了。相关的Deployment有:
Pods
Deployment
一个最简单的例子如下:
apiVersion: apps/v1 kind: Deployment metadata: name: nginx-deployment spec: selector: matchLabels: app: nginx replicas: 1 template: metadata: labels: app: nginx spec: containers: - name: nginx image: nginx:1.19.0 ports: - containerPort: 80 --- apiVersion: v1 kind: Service metadata: labels: app: nginx name: nginx-service spec: ports: - port: 80 name: nginx-service protocol: TCP targetPort: 80 selector: app: nginx type: ClusterIP --- apiVersion: extensions/v1beta1 kind: Ingress metadata: name: example-ingress annotations: kubernetes.io/ingress.class: nginx spec: rules: - http: paths: - path: / backend: serviceName: nginx-service servicePort: 80 host: localhost
这样配置后,当我们访问http://localhost/时,就会把我们的请求转发到nginx-service的80端口上去。如下所示:
http://localhost/
nginx-service
80
当要访问多个服务时,事情就变得复杂起来了。访问多个服务,有两种配置方式,一种是通过URL路径匹配再转发,另一种是通过子域名转发。
URL
子域名
通过子域名转发如下配置:
apiVersion: extensions/v1beta1 kind: Ingress metadata: name: example-ingress annotations: kubernetes.io/ingress.class: nginx spec: rules: - http: paths: - path: / backend: serviceName: nginx-service servicePort: 80 host: nginx.localhost - http: paths: - path: / backend: serviceName: springboot-service servicePort: 8080 host: springboot.localhost
为了节省篇幅,这里就只展示Ingress的配置了。
访问http://nginx.localhost/如下:
http://nginx.localhost/
访问http://springboot.localhost/swagger-ui.html如下,注意这个URL带了子路径swagger- ui.html:
http://springboot.localhost/swagger-ui.html
swagger- ui.html
那通过URL路径匹配方式是不是这样配置呢?
apiVersion: extensions/v1beta1 kind: Ingress metadata: name: example-ingress annotations: kubernetes.io/ingress.class: nginx spec: rules: - http: paths: - path: /nginx backend: serviceName: nginx-service servicePort: 80 host: localhost - http: paths: - path: /springboot backend: serviceName: springboot-service servicePort: 8080 host: localhost
这样配置后,会直接报404,但不是Ingress的404,而是Nginx或Springboot的404。说明请求已经成功转发到对应的service了,但路径有问题。原因是,当这样配置时,Ingress会把path也转发到service上。所以实际效果如下:
404
Nginx
Springboot
service
path
localhost/nginx --> nginx-service/nginx localhost/springboot --> springboot-service/springboot
所以服务的Web Context路径要与配置的path匹配。比如nginx-service的基础路径就要改为/nginx,而不能是/了。
Web Context
/nginx
/
如果就想保持服务的Web Context路径是/,那就需要配置rewrite规则,如nginx.ingress.kubernetes.io/rewrite-target: /$1。
rewrite
nginx.ingress.kubernetes.io/rewrite-target: /$1
过了一遍,坑真不少。使用子域名感觉是比较好的方式。另外,Ingress还有一个坑,它是实现HTTP/HTTPS转发的,但TCP就不行了,比如我在Kubernetes安装了一个MySQL数据库,需要把地址和3306以TCP方式暴露给外面,就比较麻烦了,我们后续再讨论吧。
HTTP/HTTPS
TCP
MySQL
3306
原文链接:https://www.cnblogs.com/larrydpk/p/13476239.html