serverfiles/openwrt/common/etc/lighttpd/compress.conf

server.modules += (
 "mod_compress"
 )

compress.cache-dir = "/www/tmp/compress"
compress.max-filesize = "1024"
compress.filetype = (
    "application/atom+xml",
    "application/javascript",
    "application/json",
    "application/rss+xml",
    "application/vnd.ms-fontobject",
    "application/x-font-ttf",
    "application/x-web-app-manifest+json",
    "application/xhtml+xml",
    "application/xml",
    "application/font-sfnt",
    "font/opentype",
    "image/svg+xml",
    "image/x-icon",
    "text/css",
    "text/html",
    "text/plain",
    "text/x-component",
    "text/xml",
)