k8s安装Ingress-Nginx
目前，DHorse(https://gitee.com/i512team/dhorse)只支持Ingress-nginx的Ingress实现，下面介绍Ingress-nginx的安装过程。
下载安装文件
首先，需要匹配Ingress-nginx版本和kubernetes版本。
在https://github.com/kubernetes/ingress-nginx可以找到，如下图所示：
笔者用的k8s版本是v1.21.2，需要安装Ingress-nginx的v1.3.1版本，下载如下文件：
wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.3.1/deploy/static/provider/cloud/deploy.yaml
替换镜像地址
查看该文件用到了哪些镜像：
[root@centos05 deployment]# cat deploy.yaml | grep image
image: registry.k8s.io/ingress-nginx/controller:v1.3.1@sha256:54f7fe2c6c5a9db9a0ebf1131797109bb7a4d91f56b9b362bde2abd237dd1974
imagePullPolicy: IfNotPresent
image: registry.k8s.io/ingress-nginx/kube-webhook-certgen:v1.3.0@sha256:549e71a6ca248c5abd51cdb73dbc3083df62cf92ed5e6147c780e30f7e007a47
imagePullPolicy: IfNotPresent
image: registry.k8s.io/ingress-nginx/kube-webhook-certgen:v1.3.0@sha256:549e71a6ca248c5abd51cdb73dbc3083df62cf92ed5e6147c780e30f7e007a47
imagePullPolicy: IfNotPresent
可以看出，所用到的镜像不在docker hub中，在registry.k8s.io中，由于国内的网络问题，拉取不到该仓库的镜像。
幸好https://dockerproxy.com/docs提供了镜像代理，按照文档的说明，我们需要把registry.k8s.io地址改为k8s.dockerproxy.com即可，替换以后的内容为：
registry.k8s.io/ingress-nginx/controller:v1.3.1@sha256:54f7fe2c6c5a9db9a0ebf1131797109bb7a4d91f56b9b362bde2abd237dd1974 ->
k8s.dockerproxy.com/ingress-nginx/controller:v1.3.1@sha256:54f7fe2c6c5a9db9a0ebf1131797109bb7a4d91f56b9b362bde2abd237dd1974
registry.k8s.io/ingress-nginx/kube-webhook-certgen:v1.3.0@sha256:549e71a6ca248c5abd51cdb73dbc3083df62cf92ed5e6147c780e30f7e007a47 ->
k8s.dockerproxy.com/ingress-nginx/kube-webhook-certgen:v1.3.0@sha256:549e71a6ca248c5abd51cdb73dbc3083df62cf92ed5e6147c780e30f7e007a47
安装
保存以后，部署ingress-nginx:
[root@centos05 deployment]# kubectl apply -f deploy.yaml
namespace/ingress-nginx created
serviceaccount/ingress-nginx created
serviceaccount/ingress-nginx-admission created
role.rbac.authorization.k8s.io/ingress-nginx created
role.rbac.authorization.k8s.io/ingress-nginx-admission created
clusterrole.rbac.authorization.k8s.io/ingress-nginx created
clusterrole.rbac.authorization.k8s.io/ingress-nginx-admission created
rolebinding.rbac.authorization.k8s.io/ingress-nginx created
rolebinding.rbac.authorization.k8s.io/ingress-nginx-admission created
clusterrolebinding.rbac.authorization.k8s.io/ingress-nginx created
clusterrolebinding.rbac.authorization.k8s.io/ingress-nginx-admission created
configmap/ingress-nginx-controller created
service/ingress-nginx-controller created
service/ingress-nginx-controller-admission created
deployment.apps/ingress-nginx-controller created
job.batch/ingress-nginx-admission-create created
job.batch/ingress-nginx-admission-patch created
ingressclass.networking.k8s.io/nginx created
validatingwebhookconfiguration.admissionregistration.k8s.io/ingress-nginx-admission created
查看结果：
[root@centos05 deployment]# kubectl get pods -n ingress-nginx -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
ingress-nginx-admission-create-fq2kq 0/1 Completed 0 11s 10.32.1.89 centos06 <none> <none>
ingress-nginx-admission-patch-fkphb 0/1 Completed 1 11s 10.32.1.90 centos06 <none> <none>
ingress-nginx-controller-5c79d9494c-rh5rn 0/1 Running 0 11s 10.32.1.91 centos06 <none> <none>
访问ingress-nginx-controller的ip，如下：
[root@centos05 deployment]# curl http://10.32.1.91
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx</center>
</body>
</html>
验证Ingress
假如，我们有一个名为hello-gradle的应用，并且有一个/hello的服务接口，并且绑定了名为www.hello-gradle.com的域名，如下图所示：
部署完该应用以后，在集群的任意节点配置host如下：
[root@centos06 deployment]# vim /etc/hosts
10.244.0.13 www.hello-gradle.com
然后通过域名访问/hello服务，如下：
[root@centos05 deployment]# curl http://www.hello-gradle.com/hello
Hello!
