http.FileServer caching files and serving old versions after edit

Question

Having issues with the http package in the core of go. It appears that the file contents is cached although the Content-Length in the response body is correct. To demonstrat

Answer 1

Until VirtualBox has fixed the issue I made a go file that can be dropped into a project to disable sendfile support for the current process, go http package will then fallback to io.Copy. Also works with boot2docker with some small docker config changes.

https://github.com/wader/disable_sendfile_vbox_linux

With newer versions of firejail you can do the same thing using:

firejail --seccomp.enotsup=sendfile ./program