What is the proper way to apply the update "gracefully"?

[Eoic]

Ideally, I want to:

1. Check for updates and download if one is available.
2. Show update download progress to the user and apply the update without any further user interaction.
3. Re-open the application when the update is applied.

How do I achieve this? Does tufup provide any hooks or different API methods that I could use to implement such update process?

---

In the code below I check for and apply updates, if any were found. I run this code in a separate thread, so that it wouldn't block the UI and show download progress to the user.

def apply_update(self):
    if not self.updater_client.check_for_updates():
        return

    self.updater_client.download_and_apply_update(
        purge_dst_dir=False,
        skip_confirmation=True,
        exclude_from_purge=None,
        progress_hook=lambda **download_args: self.update_progress_signal.emit(download_args),
    )

However, when the update is downloaded, it opens up a console window, but does not close the application. The output at this moment is shown below. Also, it cannot copy files when the application is running and I have to close the application manually for the update to succeed.

Waiting 2 seconds... Retrying...
            Newer                 12.6 m        app.exe
2023/12/15 23:03:07 ERROR 32 (0x00000020) Copying File C:\Users\<USER>\AppData\Local\Temp\tufup\app.exe
The process cannot access the file because it is being used by another process.
Waiting 2 seconds... Retrying...
            Newer                 12.6 m        app.exe

[dennisvang]

1. Check for updates and download if one is available.

Basically do what you're doing in your example above.

2. Show update download progress to the user and apply the update without any further user interaction.

The skip_confirmation=False takes care fo the user interaction in the console. If you also want to prevent the console window from appearing, have a look at the process_creation_flags arg, as described in #90.

That is, assuming you're on Windows.

3. Re-open the application when the update is applied.

There's a batch_template hook that allows you to provide a custom batch script. Have a look at this discussion for details.

On macOS the app is already restarted out-of-the-box. See source

... I run this code in a separate thread, ...

Tufup was not designed with multi-threading in mind.

It can probably be done, but you'd have to jump through some hoops:

Off the top of my head, I think you could probably run the _download_updates() step in a separate thread, as long as you run the _apply_updates() step in your main thread. Tufup checks if the files for new updates have already been downloaded, so the update would then be applied on the next run of your app.

However, use at your own risk: this is untested and not officially supported.

I'm also not quite sure if, and how, the underlying python-tuf package handles multi-threading (see e.g. 8, 7, 6).

... However, when the update is downloaded, it opens up a console window, but does not close the application. ... Also, it cannot copy files when the application is running ...

That's probably all due to the multi-threading. The _apply_updates() step must run on the main thread.