Flatpak related issues

I posted in the Flatpak request thread but received no response, and tried my luck getting a response from the dev team via email but that didn’t work also, so I hope I’ll get more feedback by posting here.

I’m packaging Insync as a Flatpak for myself (see here) but if the issues will be resolved then it can be picked up for distributing via Flathub.org.

Blocking issues: must be fixed or get workarounds

  1. Traybar status icon is missing. /usr/share/icons/hicolor/48x48/status is probably hardcoded, Insync is not considering $XDG_DATA_DIRS.
    /usr/share/ and /usr/share/runtime/share are from the Flatpak runtime while /app/share is from the Flatpak packaged app. So Insync should at least also check /app/share/.
    I was able to confirm that the problem is with /usr/share being the only path used for looking up the icons by injecting them into the Flatpak runtime (changing the filesystem), updating the icons cache, and watch the status icon appear.

  2. The use of Unix file socket at /tmp/insync${UID}.sock to check if another Insync instance already running and communicate with file-manager extensions.
    I believe this should be changed to a Linux named socket that could be shared across the network (edit:) namespace, accessible to the host, and other Flatpak applications (that could be file-managers).

Not blocking but would nice to have:

  1. Check $XDG_CONFIG_HOME value before defaulting to ~/.config/Insync as the settings folder.

Please consider fixing these issues.
It’s very easy to build and install the Flatpak package.

flatpak instal flathub org.gnome.Sdk//3.36
flatpak-builder --install --user --force-clean --state-dir=build/flatpak-builder --repo=build/flatpak-repo build/flatpak-target com.insynchq.insync.yaml

Hi @tinywrkb, thanks for your efforts, it’s a pity you are not getting answered here either :worried:

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Two other alternatives for the Unix file socket:

  1. Instead of hard-coding the socket path as /tmp/insync${UID}.sock use instead $TMPDIR/insync${UID}.sock and fall back to /tmp/insync${UID}.sock if $TMPDIR is empty or does not exist.

  2. Use d-bus instead.

I noticed a similar status icon issue with another QT5 app so I’m guessing the same workaround I used for the other app could be applied to Insync.
My guess is that Insync is loading the status icons from an hardcoded path that isn’t available on Flatpak as Insync is installed at /app.
So instead, I suggest that Insync would use QIcon::fromTheme to load icons for the status bar and that should solve the issue, at least as long as icons were exported by Flatpak, meaning they should have the AppData app-id as a prefix, e.g. com.insynchq.insync.status-alert.png and trayIcon->setIcon(QIcon::fromTheme("com.insynchq.insync.status-alert"));

Considering the lack of response from an informed Insync representative, I’m posting here my last opinion on the matter.
I don’t think anyone that is not an Insync developer should put any effort into trying to publish a Flatpak package on Flathub before these issues are resolved.

There are blocking issues:

  1. No system status icon. Probably can be easily solved by Insync if they would load a pixmap instead of using a file path and this change should have zero negative affect.
    A solution that will be also compatible with desktop icon themes is to use the Freedesktop icon naming (with QIcon::fromTheme) but this means it should follow the Flatpak guidelines for icon exports by using the AppData app-id as a prefix.

  2. Using an IPC for communicating between the Insync daemon to file manager extensions that can compatible with both host applications and Flatpak applications. The current Unix file socket at /tmp is terrible for Flatpak, it means every packaged Flatpak file manager that wants to use the Insync extension would need to add /tmp filesystem permission, and I don’t see this happening.
    My suggestion is to use D-Bus, it should be perfect for this. It should be possible to also a Linux named socket without making much changes to the code, but I’m not sure this is a great idea security-wise, and it will break in the future when Flatpak will have network namespaces capability.

If both these will be solved then Insync will be ready for being packaged as a Flatpak package.

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Thanks for investigating this @tinywrkb.

I hope the devs will take a look at your findings at some point and implement this feature.

It’s being a while since their last word on that matter AFAIK.

After looking at the tray icon problem in a different application I think I found another workaround that requires minimal changes to Insync’s code.

I don’t have access to Insync’s code but I’m guessing it’s doing something like

There are two problems with this:

  1. /usr is where the runtime lives while /app is for the app, so the status icons are not in /usr.
  2. When setIcon method is used like that (and not with QIcon::fromTheme) it creates an icon file in $XDG_RUNTIME_DIR/qt-trayicon-XXXXX.png and set this path as the value of IconName in the D-Bus interface. This path is not accessible on the host so the system tray app can not load the icon.

The workaround for 2. is to set XDG_RUNTIME_DIR as a path that is accessible on the host, I settled on export XDG_RUNTIME_DIR=$XDG_RUNTIME_DIR/app/$FLATPAK_ID, and so far it doesn’t seem to break anything. This is a change to the Flatpak packaging, no Insync code change is needed. edit: this seems to break Wayland but I think it’s acceptable a a temporary solution.

A possible workaround for 1. would be to test if /usr/share/icons/hicolor/48x48/status/insync-*.png are available, and if not to try /app/share/icons/hicolor/48x48/status/insync-*.png. This should be a pretty minimal change to Insync’s code, that’s if my guess about the current implementation is correct.