在flask应用中，使用request.remote_addr始终获得172.21.0.7（localhost），nginx实际上获得了IP地址，我还设置了proxy_set_header HTTP-X_REAL_IP $remote_addr;
看起来它从本地主机启动一个新请求，并且request.environ中不包含“ HTTP-X_REAL_IP”，
nginx-container_1 | 113.118.227.195 - - [23/Jul/2019:06:24:07 +0000] "GET /settings HTTP/1.1" 200 5902 "http://hit-the-road.cc/login" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36" "-"
website_1 | 172.21.0.7 - - [23/Jul/2019:06:24:07 +0000] "GET /settings HTTP/1.0" 200 5902 "http://hit-the-road.cc/login" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36" in 25178µs
我该怎么做才能获得客户端IP地址？