Inotify on shared drives does not work

[DeltaWhy]

I'm using docker-compose to run a Node.js application with nodemon. The application source is on the Windows host and mounted on the container so that I can make changes without rebuilding. However, nodemon does not pick up file changes. If I exec a shell inside the container and touch one of the files from there, nodemon picks it up and restarts the app, but any changes from Windows don't seem to trigger the inotify events.

[friism]

@DeltaWhy thanks, this is a known limitation that we're trying to figure out how to address.

nodemon has a fallback polling mode that I recommend you try: https://github.com/remy/nodemon#application-isnt-restarting

@londoncalling I checked the FAQ, and it looks like we don't have a mention that inotify doesn't work on Windows - it might be good to add.

[londoncalling]

@friism adding it now to the FAQs

[rn]

@DeltaWhy We are using SMB for the file sharing and the Linux SMB implementation does not support change notifications. We have update the FAQ accordingly andI'm closing this issues.
Thanks for reporting

[garveen]

https://wiki.samba.org/index.php/Samba_3.0_Features_added/changed

Samba 3.0.25:

New file change notify subsystem which is able to make use of inotify on Linux.

[rn]

@garveen unfortunately, the linux kernel implementation of SMB (in ./fs/cifs) does not support inotify. There are various comments in the code that the older dnotify once was supported (and it is marked as experimental) but none of the code calls into the fsnotify API.

UPDATE: I think the above refers to the Linux SMB server being able to generate SMB change notification from inotify events. The opposite direction is what is needed by Docker for Windows: SMB change notifications generated by the server on the host need to be translated into the events on Linux

[garveen]

@rneugeba maybe other than smb:

If we have a tool that listen on native Windows' file system APIs, communicate with MobyLinux and generate Linux events, it would be great.

Does this idea practicable?

[DeltaWhy]

I assume Hyper-V doesn't have anything akin to VirtualBox shared folders? Inotify works great with Docker Toolbox as well as Vagrant.

[rn]

@DeltaWhy I haven't seen anything in the VBox source suggesting they support inotify on the shared folders, but I may have looked at the wrong place, but there seems plenty of evidence on the web that it doesn't, like for example: https://www.virtualbox.org/ticket/10660?cversion=0&cnum_hist=1

[kidlj]

@rneugeba @friism
Vagrant can make bi-directional file changes synchronization between Windows host and Linux guest machines. And Vagrant takes several ways to achieve this:

SMB: https://www.vagrantup.com/docs/synced-folders/smb.html
RSync: https://www.vagrantup.com/docs/synced-folders/rsync.html
Virtualbox shared folders: https://www.vagrantup.com/docs/synced-folders/virtualbox.html

Hope you can get some inspirations from there! Thank you D4W developers.

[friism]

@kidlj yes, moving files and file changes back and forth works fine (as it does with Docker for Windows), but the inotify change notifications are not, and not with any of those solutions that you linked to either, at least not that I know of. Do you have an example of inotify working with either SMB, RSync or vbox shared folders?

[kidlj]

@friism Thank you for the explanation. I thought inotify was the same as file changes synchronization, but now I get it.

I just found a vagrant solution for the same inotify issue, could it help?
https://github.com/adrienkohlbecker/vagrant-fsnotify

[friism]

@kidlj I don't think it works for Windows, but might be an interesting model. Maybe @rneugeba has thoughts.

[DeltaWhy]

I guess I was mistaken. It looks like mocha --watch works on both (I guess it's using polling) and nodemon doesn't by default, which is maybe why I got confused.

Rsync with rsync-auto should trigger inotify events since it's touching files on the Linux native FS, right? But that probably won't work for sharing a whole drive 😉

Vagrant-fsnotify looks very interesting but I wonder if that approach would also have performance issues when sharing a whole drive. You might need a Linux kernel module to tell what's being watched on the CIFS mount so the host side can watch those same things rather than the whole drive.

[blaggacao]

This hurts too much for beeing closed.