Linux Mint Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead

Solving Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead in Linux Mint

Hi! This Guide is Solving the “Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead” Issue in Mint 21+ GNU/Linux.

The former apt-key is deprecated, except for the use of apt-key del in maintainer scripts to remove existing keys from the main keyring.

1. 1. Setting up Key

   Now to Set up GPG Key in Mint
   First, set the Target Directory with:

   sudo install -m 0755 -d /etc/apt/keyrings

   The General Command is:

   curl -fsSL [MYKEYURL].[GPG/ASC] | sudo gpg --dearmor -o /etc/apt/keyrings/[MYKEYNAME].gpg

   Amend conformly the [MY…] in the above Command.
   The “dearmor” Flag provide to the possible Decryption.
   So for example:

   curl -fsSL http://download.virtualbox.org/virtualbox/debian/oracle_vbox_2016.asc | sudo gpg --dearmor -o /etc/apt/keyrings/virtualbox.gpg

2. 2. Fixing Repo

   Next, provide to Sign Apt Repository properly
   So Edit the Configuration File:
   (Here for simplicity with the nano Editor, but you can just use Anyone.)

   sudo nano /etc/apt/sources.list.d/[MYREPO].list

   And modify the Line inserting:

   [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/[MYKEY].gpg]

   So in case to follow the former Example like:

   [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/virtualbox.gpg]

   Ctrl+w to Search.
   Finally, Ctrl+x to Save & Exit from nano Editor.
   Last, Refresh the Apt Sources:

   sudo apt update

   And Happy Apt Software! ;)