Virtualbox shared volumes not picking up changes

[cmheisel]

With docker-machine 0.6 and Virtualbox 5.0.16 with OS X I've encountered situations where changes to files on my Mac filesystem that are shared via docker-compose volumes aren't picked up by the running docker container.

I've got more details and a test script here: https://github.com/cmheisel/docker-machine-fstest

It seems like installing docker-machine-nfs resolves the issue

Interestingly, it seems like using Alpine base images exposes the issue, at least with Python apps.

[thaJeztah]

I think this may be because VirtualBox shared folders don't support inotify (and they won't be supporting that, see: https://www.virtualbox.org/ticket/10660)

Also see moby/moby#18246, which has some more related issues linked

[cmheisel]

@thaJeztah I didn't think about inotify support. That would explain the live-reloading.

I'm seeing the same behavior if you docker-compose stop and docker-compose up to restart the containers, the change you made doesn't show. I updated my test script to verify. That seems like something larger than inotify support.

[thaJeztah]

A colleague just mentioned that this could be due to sendfile not working on vboxsf. Don't know if there's an option to disable that in your python app?

[cmheisel]

@thaJeztah What's weird is the python app reloads on change with Debian-based distros, but not Alpine-based. And that Nginx isn't picking up changes either live or after a container restart

What I've found is below, with the really weird stuff in bold:

Distro/App	Changes appear on file change	Changes appear on container restart
Alpine/Flask	NO	NO
Alpine/Nginx	NO	NO
Debian/Flask	Yes	Yes
Debian/Nginx	NO	NO

[thaJeztah]

Nginx may be partly related to sendfile (also see http://serverfault.com/questions/269420/disable-caching-when-serving-static-files-with-nginx-for-development), although it surprises me that it doesn't pick up those changes even after a container restart. Perhaps @ncopa has an idea what difference Alpine makes in this situation.

You may be interested in https://blog.docker.com/2016/03/docker-for-mac-windows-beta/, which solves a lot of issues in this area

[cmheisel]

@thaJeztah I got access to the beta and all the tests passed with that, so it must be virtualbox/vboxfs related.

[thaJeztah]

@cmheisel excellent! Enjoy the beta, I hope you like it!

[nathanleclaire]

Closing this as nothing seems actionable on our end