nginx 动态跨域配置

方法一：

server {
    .....
    set $cors_origin "";
    if ($http_origin ~* "a.xxxx.com") {
        set $cors_origin $http_origin;
    }
    if ($http_origin ~* "b.xxxx.com") {
        set $cors_origin $http_origin;
    }
    if ($http_origin ~* "c.xxxx.com") {
        set $cors_origin $http_origin;
    }
    add_header 'Access-Control-Allow-Origin' $cors_origin;
    add_header 'Access-Control-Allow-Credentials' 'true';
    add_header 'Access-Control-Allow-Headers' 'X-Requested-With';
    .....
}

方法二：

map $http_origin $cors_origin{
    default 0;
    "~http://a.xxxx.com" http://a.xxxx.com;
    "~http://b.xxxx.com" http://b.xxxx.com;
    "~http://b.xxxx.com" http://b.xxxx.com;
}

server
{
    .....
    location / {
        add_header 'Access-Control-Allow-Origin' $cors_origin;
        add_header 'Access-Control-Allow-Credentials' 'true';
        add_header 'Access-Control-Allow-Headers' 'X-Requested-With';
    }
    .....
}

方法三:

server
{
    .....
    location / {
        if ( $http_origin ~ (.*).xxxxx.com ) {
            add_header Access-Control-Allow-Origin $http_origin;
            add_header 'Access-Control-Allow-Credentials' 'true';
            add_header 'Access-Control-Allow-Headers' 'X-Requested-With';
        }
    .....
 }

但上面的方法，在CDN场景下好像没作用。

参考：https://www.cnblogs.com/sunmmi/articles/5956554.html