1、第一种：不好使
在nginx的配置中，在https的server站点添加如下头部：
add_header Strict-Transport-Security “max-age=63072000; includeSubdomains; preload”;
这样当第一次以https方式访问我的网站，nginx则会告知客户端的浏览器，以后即便地址栏输入http，也要浏览器改成https来访问我的nginx服务器。
原文链接：https://blog.csdn.net/socho/article/details/72456008

server {listen       443 ssl;listen       [::]:443 ssl;server_name  beta.deepcloudsdp.com saas2.deepcloudsdp.com;add_header Strict-Transport-Security "max-age=63072000; includeSubdomains; preload";
#        ssl on;ssl_certificate      /project/redcore/base/nginx/conf/SSL/cert.pem;ssl_certificate_key  /project/redcore/base/nginx/conf/SSL/privkey.pem;ssl_session_cache    shared:SSL:1m;ssl_session_timeout  5m;

2、第二种

server {listen       80;listen [::]:80;server_name  saas2.deepcloudsdp.com;rewrite ^(.*)$  https://$host$1 permanent;    # 这行#rewrite ^/(.*) https://$server_name/$1 permanent;  # 或这样root /project/redcore/webRoot/public;index index.html;proxy_set_header X-Real-IP $remote_addr;location ~* /client/v[345]/push/sse {rewrite /client/v[345]/push(.*) $1 break;proxy_pass http://172.17.123.5:8181;proxy_set_header Connection '';proxy_http_version 1.1;chunked_transfer_encoding off;proxy_buffering off;proxy_cache off;proxy_read_timeout 600s;proxy_connect_timeout 600;}