原創 雲計算技術棧 https://mp.weixin.qq.com/s/bOuZI6KC92NBC3SOgDFQDg
在使用K8S的Ingress的時候需要我們自己來選擇一個或者多個要使用的Ingress Controller。最常用的就是基於Nginx的Ingress控制器。但是很多人不清楚基於Nginx的控制器不止一種，而且使用上也是有不一致的。這就有必要在使用和遇到問題查閱文檔、資料的時候知道自己用的是哪一個。查找的資料是不是對應的自己使用的Ingress 控制器實現。這就有了本篇翻譯，希望可以讓大家少走彎路。
背景
常見的兩種基於Nginx的Ingress Controller實現：
-
kubernetes/ingress-nginx
-
nginxinc/kubernetes-ingress
NOTE：1 爲kubernetes社區維護的版本 NOTE：再次強調，在查閱資料的時候一定注意是否是自己使用的Ingress Controller對應的文檔。
判斷自己使用的是哪個版本
可以通過檢查自己的Ingress Controller使用的Docker鏡像來區分。nginxinc/kubernetes-ingress Ingress控制器的Docker鏡像在 DockerHub上就存在，名字是nginx/nginx-ingress.
不同Ingress 控制器的主要差別
下面的表格列舉了不同版本的Ingress 控制器之間的差別。這裏之所以出現了三種是因爲基於Nginx商業版的nginx plus也有自己的一些特性。所以也一併列舉了。
| 功能/特徵 | kubernetes/ingress-nginx | nginxinc/kubernetes-ingress with NGINX | nginxinc/kubernetes-ingress with NGINX Plus |
|---|---|---|---|
| 基本信息 | |||
|
維護者 |
Kubernetes community | NGINX Inc and community | NGINX Inc and community |
| NGINX version | Custom NGINX build that includes several third-party modules | NGINX official mainline build | NGINX Plus |
| 商業支持 | N/A | N/A | Included |
| Ingress實例的LB相關設置 | |||
| Merging Ingress rules with the same host | Supported | Supported via Mergeable Ingresses | Supported via Mergeable Ingresses |
| HTTP load balancing extensions - Annotations | See the supported annotations | See the supported annotations | See the supported annotations |
| HTTP load balancing extensions -- ConfigMap | See the supported ConfigMap keys | See the supported ConfigMap keys | See the supported ConfigMap keys |
| TCP/UDP | Supported via a ConfigMap | Supported via a ConfigMap with native NGINX configuration | Supported via a ConfigMap with native NGINX configuration |
| Websocket | Supported | Supported via an annotation | Supported via an annotation |
| TCP SSL Passthrough | Supported via a ConfigMap | Not supported | Not supported |
| JWT validation | Not supported | Not supported | Supported |
| Session persistence | Supported via a third-party module | Not supported | Supported |
| Canary testing (by header, cookie, weight) | Supported via annotations | Supported via custom resources | Supported via custom resources |
| Configuration templates *1 | See the template | See the templates | See the templates |
| 基於CRD的擴展功能 | |||
| HTTP load balancing | Not supported | See VirtualServer and VirtualServerRoute resources. | See VirtualServer and VirtualServerRoute resources. |
| 部署方式 | |||
| Command-line arguments *2 | See the arguments | See the arguments | See the arguments |
| TLS certificate and key for the default server | Required as a command-line argument/ auto-generated | Required as a command-line argument | Required as a command-line argument |
| Helm chart | Supported | Supported | Supported |
| 運維相關 | |||
| Reporting the IP address(es) of the Ingress controller into Ingress resources | Supported | Supported | Supported |
| Extended Status | Supported via a third-party module | Not supported | Supported |
| Prometheus Integration | Supported | Supported | Supported |
| Dynamic reconfiguration of endpoints (no configuration reloading) | Supported with a third-party Lua module | Not supported | Supported |
Notes:
*1 -- 不同的Ingress控制器使用的Configuration templates格式是不同的.
*2 -- 由於命令行參數存在差別，所以不同的Ingress控制器的部署配置文件（deployment manifest）也是各不相同的。
更換Ingress 控制器
需要根據上面章節描述的各個方面來處理差異。選擇合適您場景的Ingress 控制器。
參考文獻
https://github.com/nginxinc/kubernetes-ingress/blob/master/docs/nginx-ingress-controllers.md