GPG error: https://packages.cloud.google.com/apt kubernetes-xenial InRelease: The following signatures couldn't be verified because the public key is not available

Trying to install Kubernetes on Ubuntu 22.04 and I have the error below:

ubuntu@test-vm-1:/etc/apt/sources.list.d$ sudo apt update

Hit:1 https://download.docker.com/linux/ubuntu jammy InRelease

Hit:3 http://archive.ubuntu.com/ubuntu jammy InRelease

Hit:4 http://security.ubuntu.com/ubuntu jammy-security InRelease

Hit:5 http://archive.ubuntu.com/ubuntu jammy-updates InRelease

Get:6 http://archive.ubuntu.com/ubuntu jammy-backports InRelease [109 kB]

Get:2 https://packages.cloud.google.com/apt kubernetes-xenial InRelease [8993 B]

Err:2 https://packages.cloud.google.com/apt kubernetes-xenial InRelease

The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B53DC80D13EDEF05

Reading package lists... Done

W: GPG error: https://packages.cloud.google.com/apt kubernetes-xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B53DC80D13EDEF05

E: The repository 'https://apt.kubernetes.io kubernetes-xenial InRelease' is not signed.

N: Updating from such a repository can't be done securely, and is therefore disabled by default.

N: See apt-secure(8) manpage for repository creation and user configuration details.

In various procedures I was trying to add the kubernetes gpg key and repo this way:

sudo curl -fsSLo /etc/apt/keyrings/kubernetes.gpg https://packages.cloud.google.com/apt/doc/apt-key.gpg

echo "deb [signed-by=/etc/apt/keyrings/kubernetes.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list

sudo apt update

But the url changed, is not more on google.

You need to change the gpg key source for apt, the new url is:

https://dl.k8s.io/apt/doc/apt-key.gpg

So, the new commands with the ur is:

sudo curl -fsSLo /etc/apt/keyrings/kubernetes.gpg https://dl.k8s.io/apt/doc/apt-key.gpg

echo "deb [signed-by=/etc/apt/keyrings/kubernetes.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list

After that I could run apt update without issues.