No sure about the DSP_URL. It looks like you're using code that was designed for DF 1.x
If it helps, in DF 2.x all calls follow the format http[s]://{dreamfactory_site_url}/api/v2/{service name}/{resourece}/{component}
htttp vs https is irrelevant as far as DreamFactory is concerned. It's all about how your web server is set up. If you're using one of the Bitnami images/packages, those default to being configured for http only.