Package grace provides a library that makes it easy to build socket based servers that can be gracefully terminated & restarted (that is, without dropping any connections).

Demo HTTP Server with graceful termination and restart: https://github.com/daaku/go.grace/blob/master/gracedemo/demo.go

http level graceful termination and restart: http://go.pkgdoc.org/github.com/daaku/go.grace/gracehttp

net.Listener level graceful termination and restart: http://go.pkgdoc.org/github.com/daaku/go.grace