解决 nextcloud there was an error accessing the token endpoint: error transferring login/v2/poll server replied: bad request 问题

在一次使用 nextcloud for windows desktop client 的时候，突然无法认证。nextcloud windows 客户端呼出了 browser 进行身份验证，但是一直失败。出现了如下图所示的错误

nextcloud there was an error accessing the token endpoint: error transferring login/v2/poll server replied: bad request

google 一段时间，终于发现这篇proxy_set_header Host $http_host;，说到点上了。

Hi guys,

I just had a similar situation on my nextcloud docker (port 80) behind nginx proxy (serving https on non-standard 9876) and redirecting to nextcloud http:80 backend). In case your setup is similar, just add this to your nginx config:

proxy_set_header Host $http_host;

I use this to prevent port change on redirect

alternatively use the common

proxy_set_header Host $host;

proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;

this preserves the initial protocol, the https…

after reloading nginx the nextcloud-client obtained the token from https correctly.
I am logged in.

随后看了一下我的 nginx reverse proxy 的 conf 配置。

在 server 块中增加配置 proxy_set_header Host $http_host;

增加后 执行 nginx -t 和 nginx -s reload 再次尝试，发现整个网站主页不能访问了。我意识到是 header 的问题。于是注释掉 proxy_set_header Host $host:$server_port; 这一行。最终再次尝试，果然可以重新访问了。而且，nextcloud windows 客户端也可以通过浏览器验证然后登录了！

分享下我的 nextcloud nginx 反代的配置