PAC file to automatically configure your proxy

plex-proxy.pac

function FindProxyForURL(url, host) {
    PROXY = "PROXY 127.0.0.1:8080; DIRECT"

    // plex.tv via proxy
    if (shExpMatch(host,"*.plex.tv")) {
        return PROXY;
    }
    // Everything else directly!
    return "DIRECT";
}