CentOS/8/Yum

/etc/yum.repos.d/centos8.repo

ls -l /etc/pki/rpm-gpg
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-8

rpm -qa gpg-pubkey* | grep -i f4a80eb5

https://www.centos.org/keys/
https://www.centos.org/keys/RPM-GPG-KEY-CentOS-Official-SHA256

curl https://www.centos.org/keys/RPM-GPG-KEY-CentOS-Official-SHA256 -o /etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

curl --fail -s https://www.centos.org/keys/RPM-GPG-KEY-CentOS-Official-SHA256 -o /etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
if [ $? -ne 0 ] ; then echo "FAIL" ; fi

rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

rpm -qa gpg-pubkey* | grep -i 8483c65d

cat > /etc/yum.repos.d/centos8.repo << "EOF"

[BaseOS]
name=CentOS-8.5.2111 - BaseOS
baseurl=http://vault.centos.org/8.5.2111/BaseOS/$basearch/os/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

[AppStream]
name=CentOS-8.5.2111 - AppStream
baseurl=http://vault.centos.org/8.5.2111/AppStream/$basearch/os/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

[PowerTools]
name=CentOS-8.5.2111 - PowerTools
baseurl=http://vault.centos.org/8.5.2111/PowerTools/$basearch/os/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

EOF