After I installed the docker, when I try to use the sudo apt update command, I get the following error:
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: focal InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7EA0A9C34573JCD8
W: Failed to fetch The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7EA0A9C34573JCD8
W: Some index files failed to download. They have been ignored, or old ones used instead.2 Answers
It looks like that you haven't added official gpg key of docker repository. Open terminal and execute below command.
curl -fsSL | sudo apt-key add -I edited :
/etc/apt/sources.list
using the vim editor : sudo vim /etc/apt/sources.listAnd I put a # character at the beginning of the line that included the docker link.
# deb-src [arch=amd64] focal stable1
