@jonradio Thanks for the pointer to network-publisher. It's almost there. It uses (through) third party server and seems too complicated for my purpose.
@kevinhaig Thanks for the suggestion.
Based on @jonradio's pointer, I found Push Syndication. It is closest to my need and am experimenting with it now. One problem noted now is that the medias are not pushed -- so reference back to private url. The search continues ...