ubuntu 에서 sudo apt-get update 오류
Reading package lists... Done Building dependency tree Reading state information... Done All packages are up to date. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error:
https://packages.cloud.google.com/apt google-cloud-ops-agent-focal-all InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B53XXXXX05 W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error:
http://packages.cloud.google.com/apt google-compute-engine-focal-stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B53XXXXX05 W: Failed to fetch
https://packages.cloud.google.com/apt/dists/google-cloud-ops-agent-focal-all/InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B53XXXXX05 W: Failed to fetch
http://packages.cloud.google.com/apt/dists/google-compute-engine-focal-stable/InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B53XXXXX05 W: Some index files failed to download. They have been ignored, or old ones used instead.