hls_forward_args

This directive appeared in version 1.5.12.

Adds arguments from a playlist request to URIs of fragments. This may be useful for performing client authorization at the moment of requesting a fragment, or when protecting an HLS stream with the ngx_http_secure_link_module module.

For example, if a client requests a playlist http://example.com/hls/test.mp4.m3u8?a=1&b=2, the arguments a=1 and b=2 will be added to URIs of fragments after the arguments start and end:

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:15
#EXT-X-PLAYLIST-TYPE:VOD

#EXTINF:9.333,
test.mp4.ts?start=0.000&end=9.333&a=1&b=2
#EXTINF:7.167,
test.mp4.ts?start=9.333&end=16.500&a=1&b=2
#EXTINF:5.416,
test.mp4.ts?start=16.500&end=21.916&a=1&b=2
#EXTINF:5.500,
test.mp4.ts?start=21.916&end=27.416&a=1&b=2
#EXTINF:15.167,
test.mp4.ts?start=27.416&end=42.583&a=1&b=2
#EXTINF:9.626,
test.mp4.ts?start=42.583&end=52.209&a=1&b=2

#EXT-X-ENDLIST

If an HLS stream is protected with the ngx_http_secure_link_module module, $uri should not be used in the secure_link_md5 expression because this will cause errors when requesting the fragments. Base URI should be used instead of $uri ($hls_uri in the example):

http {
    ...

    map $uri $hls_uri {
        ~^(?<base_uri>.*).m3u8$ $base_uri;
        ~^(?<base_uri>.*).ts$   $base_uri;
        default                 $uri;
    }

    server {
        ...

        location /hls {
            hls;
            hls_forward_args on;

            alias /var/videos;

            secure_link $arg_md5,$arg_expires;
            secure_link_md5 "$secure_link_expires$hls_uri$remote_addr secret";

            if ($secure_link = "") {
                return 403;
            }

            if ($secure_link = "0") {
                return 410;
            }
        }
    }
}