Header V3 DSA signature: NOKEY, key ID 6b8d79e6

centos 使用 rpm安装的时候提示

Header V3 DSA signature: NOKEY, key ID 6b8d79e6

解决办法：

cd /etc/pki/rpm-gpg 
wget http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6 
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY*