Web服务安全通道：ngrok
ngrok 是一个反向代理，通过在公共的端点和本地运行的 Web 服务器之间建立一个安全的通道。ngrok 可捕获和分析所有通道上的流量，便于后期分析和重放。
Demo your latest code
ngrok creates a tunnel from the public internet (http://subdomain.ngrok.com) to a port on your local machine. You can give this URL to anyone to allow them to try out a web site you're developing without doing any deployment.
Understand HTTP services
ngrok captures all traffic through the tunnel. It displays information about the HTTP traffic for your inspection. Raw request/response bytes, parsed headers and form data, JSON/XML syntax checking and more are included.
Replay Requests
Developing services which consume webhooks can be challenging if the hooks are labor-intensive to generate. Use ngrok's replay request feature to iterate quickly on a new feature without switching contexts to generate new requests.
网络架构如下图所示：
