when I did
apt-get update -y
I got the following errors
W: GPG error: http://security.ubuntu.com/ubuntu oracular-security InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 871920D1991BC93C
I am not quite sure why that happened with "security.ubuntu.com" and "archieve.ubuntu.com" with the fresh docker image download from the docker hub.
I tried following suggestion from https://stackoverflow.com/questions/68992799/warning-apt-key-is-deprecated-manage-keyring-files-in-trusted-gpg-d-instead/71384057#71384057 by downloading the key using the following URL https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x871920D1991BC93C, and modify both /etc/apt/sources.list and /etc/apt/sources.list.d/ubuntu.sources in order to replace the /usr/share/keyrings/ubuntu-archive-keyring.gpg with my newly download file.
But sound like no luck, Sound like even the key I downloaded from https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x871920D1991BC93C gives the error "signatures couldn't be verified because the public key is not available: NO_PUBKEY 871920D1991BC93C"
Please help.
NOTE:
In Dockerfile, I use ubuntu:oracular.
FROM ubuntu:oracular
