今天把项目升级了 asp.net core 到 2.1 的版本，使用了 signalr  的功能，由于阿里云不支持 websocket 协议，所以使用了 nginx 代理方式来解决，后续就报了一个登陆的 404 错误。

POST http://xxx.xxx.xxx.xxx/account/login HTTP/1.1Host: xxx.xxx.xxx.xxxConnection: keep-aliveContent-Length: 217Cache-Control: max-age=0Origin: http://xxx.xx.xxx.xxUpgrade-Insecure-Requests: 1Content-Type: application/x-www-form-urlencodedUser-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8Referer: http://xxx.xx.xxx.xx/account/loginAccept-Encoding: gzip, deflateAccept-Language: zh-CN,zh;q=0.9Cookie: .AspNetCore.Antiforgery.7cgpZYq1ZXs=CfDJ8KJwTda_rr5JqCpgr4JkvXPer9JtjzFiA6KXhxp_8m9gZOJgqfDqP-AhE7u-AgDz3PCB1Ij7YCwQKP6qevtpPPMZcWfGlk4-6v_v6TqFe8yPcQ-_wPmB5OqgxSpALzp9mP13S7HQVhSg6T8Hxm7Q1tI__RequestVerificationToken=CfDJ8KJwTda_rr5JqCpgr4JkvXOlA8q_Wj9j8_hKa5BXlVTLeL65qofkijsny-O8pTxOIc7j5Vqrkw9SrKV-xOoChhghUf60qv9Juqm_epLjs-qKXOkG5SEhETtnrWDmLM8nlhEpMkOyuY2p5GnGNtZ7m4k&userName=irving&pwd=xxxHTTP/1.1 400 Bad RequestServer: nginx/1.10.3 (Ubuntu)Date: Fri, 01 Jun 2018 14:52:04 GMTContent-Length: 0Connection: keep-alive

server {         listen 80;         location / {            proxy_pass http://localhost:5000;            proxy_set_header X-Real-IP $remote_addr;            proxy_set_header Host $host;            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;         }       location ~ ^/(.*)/ws${        proxy_pass http://localhost:5000;            proxy_set_header Upgrade $http_upgrade;            proxy_set_header Connection "Upgrade";            proxy_set_header Host $http_host;            proxy_read_timeout 36000s;        }       }

https://www.orgleaf.com/2280.html

http://nginx.org/en/docs/http/websocket.html

http://dbaplus.cn/news-21-1129-1.html

https://www.digitalocean.com/community/tutorials/how-to-install-nginx-on-ubuntu-16-04