解决The following signatures couldn't be verified because the public key is not available: NO_PUBKEY FEEA9169307EA071 NO_PUBKEY 8B57C5C2836F4BEB

问题

yang@k8s-master:/etc/apt/sources.list.d$ sudo apt update
Get:1 https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial InRelease [9,383 B]
Hit:2 http://repo.huaweicloud.com/ubuntu focal InRelease
Hit:3 http://repo.huaweicloud.com/ubuntu focal-updates InRelease
Hit:4 http://repo.huaweicloud.com/ubuntu focal-backports InRelease
Err:1 https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY FEEA9169307EA071 NO_PUBKEY 8B57C5C2836F4BEB
Hit:5 http://repo.huaweicloud.com/ubuntu focal-security InRelease
Hit:6 https://download.docker.com/linux/ubuntu focal InRelease
Reading package lists... Done
W: GPG error: https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY FEEA9169307EA071 NO_PUBKEY 8B57C5C2836F4BEB
E: The repository 'https://mirrors.aliyun.com/kubernetes/apt 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.

解决方法：

sudo gpg --keyserver keyserver.ubuntu.com --recv FEEA9169307EA071  # 此公钥根据自己生成的填写

sudo gpg --export --armor FEEA9169307EA071 | sudo apt-key add -

sudo apt-get update