登录依赖cookie，且cookie是跨域不共享的，如果是前后台分离开发，肯定存在跨域的情况，有时需要在服务器上同时启动前后台服务，然后使用nginx服务器配置反向代理来解决前后台跨域问题
参考：https://www.runoob.com/linux/nginx-install-setup.html

步骤

1. 下载：https://nginx.org/en/download.html （下载速度很快，压缩包）
2. 解压到指定位置，比如C盘根目录，并重命名为nginx
3. 使用vscode打开 windows:C:\nginx\conf\nginx.conf

• 参数：
  worker_processes 1; （cpu是几核的，负载均衡）
  listen 9090; （监听端口）
  proxy_pass http://localhost:9001; （前台服务端口）
  proxy_pass http://localhost:9000; （后台服务端口）
• 可以做多服务跨域处理

#user  nobody;
worker_processes 1;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       mime.types;
    default_type  application/octet-stream;

    #log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
    #                  '$status $body_bytes_sent "$http_referer" '
    #                  '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    server {
        listen       9090;
        server_name  localhost;
        location / {
            proxy_pass http://localhost:9001;
        }
        location /dev-api/ {
            proxy_pass http://localhost:9000;
            proxy_set_header Host $host;
        }
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }

    server {
        listen       3030;
        server_name  localhost;
        location / {
            proxy_pass http://localhost:3001;
        }
        location /api/ {
            proxy_pass http://localhost:3000;
            proxy_set_header Host $host;
        }
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }


    # another virtual host using mix of IP-, name-, and port-based configuration
    #
    #server {
    #    listen       8000;
    #    listen       somename:8080;
    #    server_name  somename  alias  another.alias;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}


    # HTTPS server
    #
    #server {
    #    listen       443 ssl;
    #    server_name  localhost;

    #    ssl_certificate      cert.pem;
    #    ssl_certificate_key  cert.key;

    #    ssl_session_cache    shared:SSL:1m;
    #    ssl_session_timeout  5m;

    #    ssl_ciphers  HIGH:!aNULL:!MD5;
    #    ssl_prefer_server_ciphers  on;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}

}

4. 保存测试
   用vscode或者win+R cmd 打开windows:C:\nginx
   输入：start nginx
   然后：nginx -t 检测是否成功启动，出现以下字样，代表nginx启动成功
   nginx: the configuration file C:\nginx/conf/nginx.conf syntax is ok
   nginx: configuration file C:\nginx/conf/nginx.conf test is successful
5. 跨域测试
   浏览器输入：http://localhost:9090/index.html （此端口是监听端口，非前后端服务端口）
   打开页面后，前端服务可以正常访问接口，证明nginx跨域代理成功
6. nginx 常用命令
   启动：start nginx 或者 nginx
   重启：nginx -s reload
   停止：nginx -s stop
   检测是否成功：nginx -t