Tray: Singleton tray

[iLLiCiTiT]

Changelog Description

Tray is now singleton process. Only one tray can be running for AYON url and settings variant (production, staging or dev variants).

Additional info

Moved webserver module to tray tool and make it as base functionality of the tool. The webserver is also used to determine if tray is running or not. Tray is storing metadata file containing webserver url, pid and information if initialization finished which is used to determine if is already running.

Added some api functions to be able receive some of these information. The most important are is_tray_running and get_tray_server_url. The get_tray_server_url should be used instead of os.environ["AYON_WEBSERVER_URL"].

Notes

More features will come in future PRs, based on what we'll need.

Testing notes:

1. Create ayon-core package and upload to AYON server.
2. Use it in a bundle.
3. Start tray.
4. Try to start tray again, it should not start second one.

[ynbot]

Task linked: AY-6113 Singleton tray with API

[BigRoy]

Overall this seemed to work.

1. I could not usually launch another tray to the same server
2. I was able to launch a dev tray to my dev server, and simultaneously launch one for my production server (both in dev mode)

---

I did notice that if I run tray very rapidly after each other (e.g. run twice almost at the same time) it gets a bit further, doesn't close down but reaches this error (in console):

Traceback (most recent call last):
  File "E:\dev\ayon-core\client\ayon_core\tools\tray\ui\tray.py", line 625, in _on_start_timer
    self._tray_widget.initialize_addons()
  File "E:\dev\ayon-core\client\ayon_core\tools\tray\ui\tray.py", line 540, in initialize_addons
    self._tray_manager.initialize_addons()
  File "E:\dev\ayon-core\client\ayon_core\tools\tray\ui\tray.py", line 187, in initialize_addons
    set_tray_server_url(
  File "E:\dev\ayon-core\client\ayon_core\tools\tray\lib.py", line 182, in set_tray_server_url
    raise TrayIsRunningError("Tray is already running.")
ayon_core.tools.tray.lib.TrayIsRunningError: Tray is already running.

Aside of that it visually appears to "keep running" from the UI perspective.

---

Aside of me seeing from the console that it's shutting down because it already had a tray running I can imagine it's very easy to miss by an artist why it may fail to launch (if they even see that at all). As such, I wonder whether we should add a pop-up that says something like "Shutting down because another Tray process is already running") Or - maybe better yet, have it shut down but send a message to the running tray to show a "tray message/popup" with that message (so it brings to attention the one that is actively running with a tray message - and when the message is clicked (and not dismissed) opens the Launcher for example. So that for the artists running it again it doesn't look like nothing happens, instead they get focused at the one that is already running?

[iLLiCiTiT]

I did notice that if I run tray very rapidly after each other (e.g. run twice almost at the same time) it gets a bit further, doesn't close down but reaches this error (in console):

Should be resolved now.

[BigRoy]

I did notice that if I run tray very rapidly after each other (e.g. run twice almost at the same time) it gets a bit further, doesn't close down but reaches this error (in console):

Should be resolved now.

Correct, works now.

---

I still think this comment is valid:

Aside of me seeing from the console that it's shutting down because it already had a tray running I can imagine it's very easy to miss by an artist why it may fail to launch (if they even see that at all). As such, I wonder whether we should add a pop-up that says something like "Shutting down because another Tray process is already running") Or - maybe better yet, have it shut down but send a message to the running tray to show a "tray message/popup" with that message (so it brings to attention the one that is actively running with a tray message - and when the message is clicked (and not dismissed) opens the Launcher for example. So that for the artists running it again it doesn't look like nothing happens, instead they get focused at the one that is already running?

But we can leave that to a separate issue and PR.

[iLLiCiTiT]

But we can leave that to a separate issue and PR.

100% agree, 100% different PR.