1. https://www.freessl.org/ 一个提供免费HTTPS证书申请的网站.
申请证书下载，配置见 https://blog.freessl.org/how-to-install-cert-in-nginx/
2. 配置好 https 后，wordpress 后台报错 404.
https://oldpan.me/archives/wordpress-wp-admim-404
location / {
index index.html index.php;
if (-f $request_filename/index.html){
rewrite (.*) $1/index.html break;
}
if (-f $request_filename/index.php){
rewrite (.*) $1/index.php;
}
if (!-f $request_filename){
rewrite (.*) /index.php;
}
}
rewrite /wp-admin$ $scheme://$host$uri/ permanent;