How can I get rid of the keyring popup showing up on Ubuntu desktop?

Turn of automatic login

—or

Set the login password to a blank value in "Passwords and Keys" (seahorse).

Background

The password of your keyring, i.e., the file containing passwords, certificates, etc., is automatically set the same as your user login password. When you log in, that keyring is automatically unlocked. However, when you automatically log in to your system, i.e. without providing your user credentials, the keyring is not unlocked. You then need to unlock it the first time an application needs something from the keyring.

There are two solutions, one more secure and another less secure.

• The more secure solution is to disable automatic login. You log in after the computer starts, and then your keyring is automatically unlocked as well for the current session.
• The less secure solution is to leave automatic login enabled, but set the login password of the keyring to nothing. Then, the keyring is not secured by a password anymore, and no password needs to be asked to access the keyring after you automatically logged in.

Howto

• You can disable automatic login in Settings - Users
• You can disable the password of the keyring by loading "Passwords and Keys". Under "Passwords", right-click the folder "Login". Select "Change password". You will need to enter your current login password before you can change the keyring password. Then leave the entries that ask for a new password blank, and ignore the warning message.

Security settings are a balance between security level and convenience. Whether you choose more security versus more convenience is your choice. The choices you make should be based on being well informed about possible risks, and your own risk assessment, which in turn depends on your specific requirements and use case.