GPG error: "public key is not available" in Ubuntu

For both server and container:

Official solution

https://developer.nvidia.com/blog/updating-the-cuda-linux-gpg-repository-key/

Remove the outdated signing key

Debian, Ubuntu, WSL

$ sudo apt-key del 7fa2af80

Install the new key

For Debian-based distributions, including Ubuntu, you must also install the new package or manually install the new signing key.

Install the new cuda-keyring package

To avoid the need for manual key installation steps, NVIDIA is providing a new helper package to automate the installation of new signing keys for NVIDIA repositories. 

Replace $distro/$arch in the following commands with values appropriate for your OS; for example:

• ubuntu1604/x86_64
• ubuntu1804/cross-linux-sbsa
• ubuntu1804/ppc64el
• ubuntu1804/sbsa
• ubuntu1804/x86_64
• ubuntu2004/cross-linux-sbsa
• ubuntu2004/sbsa
• ubuntu2004/x86_64
• ubuntu2204/sbsa
• ubuntu2204/x86_64
• wsl-ubuntu/x86_64

Debian, Ubuntu, WSL

$ wget https://developer.download.nvidia.com/compute/cuda/repos/$distro/$arch/cuda-keyring_1.0-1_all.deb
$ sudo dpkg -i cuda-keyring_1.0-1_all.deb

Common issues and solutions on Debian-based distros

Here are some common errors that we’ve helped people with. If you see an error not listed here, please comment below.

Duplicate .list entries

{{E: Conflicting values set for option Signed-By regarding source
https://developer.download.nvidia.com/compute/cuda/repos/ubuntu1804/x86_64/ /: 
/usr/share/keyrings/cuda-archive-keyring.gpg !=
E: The list of sources could not be read.}}

Solution: If you previously used add-apt-repository to enable the CUDA repository, then remove the duplicate entry.

sudo sed -i '/developer\.download\.nvidia\.com\/compute\/cuda\/repos/d' /etc/apt/sources.list

Also check for and remove cuda*.list files under the /etc/apt/sources.d/ directory.

----------------------------------------------

Error

Err:6 http://packages.microsoft.com/repos/azurecore focal InRelease

  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EB3E94ADBE1229CF

Reading package lists... Done

W: GPG error: http://packages.microsoft.com/repos/azurecore focal InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EB3E94ADBE1229CF

Solution

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys
EB3E94ADBE1229CF

# 

Problem in docker

RUN sudo apt-key adv --fetch-keys https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/3bf863cc.pub

or 

RUN wget https://developer.download.nvidia.com/compute/cuda/repos/$distro/$arch/cuda-keyring_1.0-1_all.deb

RUN sudo dpkg -i cuda-keyring_1.0-1_all.deb

Update 2023-0705

Error:

gpgkeys: key F60F4B3D7FA2AF80 not found on keyserver

https://askubuntu.com/questions/831386/gpgkeys-key-f60f4b3d7fa2af80-not-found-on-keyserver

The solution is:

wget -qO - https://developer.download.nvidia.com/compute/cuda/repos/ubuntu1804/x86_64/7fa2af80.pub | sudo apt-key add -

as documented here: https://developer.nvidia.com/cuda-downloads -> Linux -> x86_64 -> Ubuntu -> 18.04 -> deb (network)

Conflict key error for "sudo apt update", can not find in source

E: Conflicting values set for option Signed-By regarding source https://developer.download.nvidia.com/compute/cuda/repos/ubuntu1804/x86_64/ /: /usr/share/keyrings/cuda-archive-keyring.gpg !=




Solution 1:
remove /etc/apt/source.list.d/cuda*, /etc/apt/source.list.d/nccl*
del cuda_key

Solution 2:

sed -i '/developer\.download\.nvidia\.com\/compute\/cuda\/repos/d' /etc/apt/sources.list.d/*
sed -i '/developer\.download\.nvidia\.com\/compute\/machine-learning\/repos/d' /etc/apt/sources.list.d/*

from:

https://askubuntu.com/questions/1424040/e-conflicting-values-set-for-option-signed-by-regarding-source-https-develope/1424054#1424054