docker安装之【异常】NO_PUBKEY

W: GPG error: https://apt.dockerproject.org ubuntu-trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F76221572C52609D

问题:执行 apt-get update 时错误

W: GPG 错误：https://apt.dockerproject.org ubuntu-trusty InRelease: 因为没有公钥，没法验证下列签名： NO_PUBKEY F76221572C52609D

解决：

# apt-key adv --keyserver keyserver.ubuntu.com --recv-keys F76221572C52609D

Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --homedir /tmp/tmp.O9IakFlDl6 --no-auto-check-trustdb --trust-model always --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyring /etc/apt/trusted.gpg.d/apt.postgresql.org.gpg --keyserver keyserver.ubuntu.com --recv-keys 16126D3A3E5C1192
gpg: 下载密钥‘3E5C1192’，从 hkp 服务器 keyserver.ubuntu.com
gpg: 密钥 3E5C1192：公钥“Ubuntu Extras Archive Automatic Signing Key <ftpmaster@ubuntu.com>”已导入
gpg: 合计被处理的数量：1
gpg: 已导入：1

#apt-get clean

#apt-get update