Lately I recognized that the RAM on this server is pretty full. A bit freed up when I removed the Piwik Analytics install recently. But still, it was too full for too little stuff running.
When you want to proxy some files in your Go project running on Google App Engine, the standard Go proxy does not work. Instead, App Engine uses a custom implementation for proxies, called urlfetch.
From time to time I build some server things in Go. The standard library already comes with a lot of functionality, but sometimes lacks essential features. One of them is a flexible router with parameters.