Performing Actions at Logon in Linux

I recently upgraded my Fedora Silverblue installation from 39 to 40 and sought to resolve two longstanding quality of life issues, the;

  1. OnlyKey client application autostarts at every logon

  2. Bluetooth soundbar requires reconnection at every logon.

Solving the first issue paved the pathway to solving the second issue.

Preventing the OnlyKey Application from Autostarting at Logon

A quick Google search turned up on the Gnome Help page which specifically addressed how to add an auto start application for all users. This was a great start but it did not tell me how to override the autostart function. Drop-in files are used extensively in Linux and are often used to override system wide behaviour so my working theory is that there should be an option to use a drop-in override file to disable the autostart behaviour which raises two further questions;

  • How can I override the autostart behaviour on a per user basis and

  • What does a compliant .desktop file look like

A Google search of “xdg auto start” turned up the freedesktop.org Desktop Application Autostart Specification which identified that;

  • /etc/xdg/autostart controls system wide behaviour and

  • ~/.config/autostart/ is used to influence per-user behaviour overriding the system wide configuration.

Okay, we’re making progress, moving onto the .desktop specification.

Once again, Google and freedesktop.org to the rescue with the Desktop Entry Specification. Reading over the .desktop specification the Hidden key appears to be what I am after. The specification states hidden should have been called deleted. It means the user deleted (at their level) something that was present at an upper level.

Turns out that /etc/xdg/autostart was not used on my installation but rather the OnlyKey application generated a .desktop file in the ~/.config/autostart/ directory. To disable the autostart behaviour I added the key Hidden=true as shown below.

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[Desktop Entry]
Version=1.0
Type=Application
Encoding=UTF-8
Name=OnlyKey App
Hidden=true
Comment=Setup and configure OnlyKey
Exec=/opt/OnlyKey/nw
Icon=/opt/OnlyKey/icon.png
Terminal=false
Categories=Utility;

A quick log out to verify it works and we’re onto problem number two.

Automatically Connecting my Bluetooth Soundbar at Logon

Having solved the first issue I am aware that there is a key in the .desktop specification called Exec which specifies the path to the executable associated with the entry. There is also another key named NoDisplay which prevents the application from displaying in the menus which will keep the Gnome App Grid clean.

Fedora uses the bluetoothctl to interface with Bluetooth devices. I can use the bluetoothctl pair command along with the device MAC address to automatically pair with the speaker at logon. The MAC address can be obtained by either looking in Bluetooth section in the Gnome Settings menu or using the bluetoothctl devices command from the terminal as displayed below.

Using the OnlyKey .desktop file as a template I end up with;

[Desktop Entry]
Name=Bluetooth Soundbar
Exec=bluetoothctl connect 64:E7:D8:86:BC:4B
NoDisplay=true
Type=Application

A quick log out to verify and both problems are solved!