nginx csp パスでcspを変更する

http context:

map $request_uri $csp_header {
    default "default-src 'self' ; script-src 'self' ; style-src 'self' 'unsafe-inline' ; img-src * 'self' data: ; font-src 'self' ; media-src * 'self' ; form-action 'self'";
    "~^/special" "default-src 'self' ; script-src 'self' 'unsafe-inline' ; style-src 'self' 'unsafe-inline' ; img-src * 'self' data: ; font-src 'self' ; media-src * 'self' ; form-action 'self'";
}

server context:

add_header Content-Security-Policy $csp_header;

https://serverfault.com/a/870465

map $uri $csp_header {
    default "default-src 'self'";
    ~^/api/ "default-src 'none'";
}