更新：2024-04-10 ，彻底重写文章

最近给前端 sub-web 、myurls 短链后端、后端 subconverter 都更新至上游最新版之后，发现又有跨域问题，折腾一番搞定

经测试，对于 https://u.0z.gs/short 接口及 POST 方法生效，均带有设置的 CORS Header
经测试，对于 任意生成的短链，如 https://u.0z.gs/6JfNauB 均带有设置的 CORS Header
经测试，对于 sub-web 新增的 从 URL 解析，使用 js Fetch API，均带有设置的 CORS Header，可以正确还原短链的订阅 URL

我发现是需要对不同接口单独配置，主要是修改 myurl 反向代理配置，最终配置文件如下

#PROXY-START/
location / {

# 对 短链子域根路径  https://u.0z.gs/ 单独处理
  location =/ {
    #Allow all requset/method/header/custom credentials
add_header 'Access-Control-Allow-Origin' $http_origin always;
add_header 'Access-Control-Allow-Headers' $http_access_control_request_headers always;
add_header 'Access-Control-Allow-Credentials' 'true' always;
add_header 'Access-Control-Allow-Methods' $http_access_control_request_method always;
add_header 'Access-Control-Max-Age' 86400 always;

if ($request_method = 'OPTIONS') {
    return 204 always;
}
       proxy_ssl_server_name on;
    proxy_ssl_name u.0z.gs;
    proxy_pass http://127.0.0.1:8002;
    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 REMOTE-HOST $remote_addr;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;
    proxy_http_version 1.1;
    # proxy_hide_header Upgrade;

    add_header X-Cache $upstream_cache_status;
  }
  # 对生成的任意短链附加 跨域 CORS
  location ^~ / {
    #Allow all requset/method/header/custom credentials
add_header 'Access-Control-Allow-Origin' $http_origin always;
add_header 'Access-Control-Allow-Headers' $http_access_control_request_headers always;
add_header 'Access-Control-Allow-Credentials' 'true' always;
add_header 'Access-Control-Allow-Methods' $http_access_control_request_method always;
add_header 'Access-Control-Max-Age' 86400 always;

if ($request_method = 'OPTIONS') {
    return 204 always;
}
       proxy_ssl_server_name on;
    proxy_ssl_name u.0z.gs;
    proxy_pass http://127.0.0.1:8002;
    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 REMOTE-HOST $remote_addr;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;
    proxy_http_version 1.1;
    # proxy_hide_header Upgrade;

    add_header X-Cache $upstream_cache_status;
  }
   # 对未命中的剩余匹配附加 跨域 CORS
   #Allow all requset/method/header/custom credentials
add_header 'Access-Control-Allow-Origin' $http_origin always;
add_header 'Access-Control-Allow-Headers' $http_access_control_request_headers always;
add_header 'Access-Control-Allow-Credentials' 'true' always;
add_header 'Access-Control-Allow-Methods' $http_access_control_request_method always;
add_header 'Access-Control-Max-Age' 86400 always;

if ($request_method = 'OPTIONS') {
    return 204 always;
}

    proxy_ssl_server_name on;
    proxy_ssl_name u.0z.gs;
    proxy_pass http://127.0.0.1:8002;
    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 REMOTE-HOST $remote_addr;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;
    proxy_http_version 1.1;
    # proxy_hide_header Upgrade;

    add_header X-Cache $upstream_cache_status;
    

    #Set Nginx Cache
    
    
    set $static_file1TCPtDBe 0;
    if ( $uri ~* "\.(gif|png|jpg|css|js|woff|woff2)$" )
    {
        set $static_file1TCPtDBe 1;
        expires 1m;
        }
    if ( $static_file1TCPtDBe = 0 )
    {
    add_header Cache-Control no-cache;
    }
}

    location ~ ^/short  {
    proxy_pass http://127.0.0.1:8002;
#Allow all requset/method/header/custom credentials
add_header 'Access-Control-Allow-Origin' $http_origin always;
add_header 'Access-Control-Allow-Headers' $http_access_control_request_headers always;
add_header 'Access-Control-Allow-Credentials' 'true' always;
add_header 'Access-Control-Allow-Methods' $http_access_control_request_method always;
add_header 'Access-Control-Max-Age' 86400 always;

if ($request_method = 'OPTIONS') {
    return 204 always;
}
       
    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 REMOTE-HOST $remote_addr;
       
    }

#PROXY-END/