While I agree that discord's code needed to be modified to handle bad data in etcd just in general ... this is not really a theoretical aspect, checking the content length so you don't try and deserialise a partial body and send crap to your business logic is http server writing 101.

Discord should've been more defensive.

The net/http devs should file this under "mistakes to admit to over beer to cheer up newbies who've just done something really dumb." (I have a number of such mistakes under my belt, we all make mistakes this stupid eventually ;)