Write headless app with tiny REST interface (in GoLang)

The app should take 3 parameters when started - INPUT URL, out URL and a INTERVAL time in seconds. The App should go every INTERVAL seconds to INPUT URL, fetch the data (json), and if successful (status 200) post the same data to the given OUTPUT URL. The app should be written in GoLang, and be runnable on all major platforms.

i.E. the app is started via "bridgeapp -in "http://10.0.0.1/get" -out "https://www.mysuperwebsite.com/post/secretKey" -interval 30 -> then it will run forever until killed.