However please ensure that any previously logged in

However, please ensure that any previously logged in oracle or grid user sessions (if any) are
logged out and logged back in for the changes to take effect.
1. Install the Oracle YUM Repo GPG Key

su 
wget -O /etc/pki/rpm-
gpg/RPM-GPG-KEY-oracle

2. Download the Needed Oracle Repo
cd /etc/yum.repos.d/
wget
3.
Install the Oracle Pre-Install RPM
yum install oracle-rdbms-server-12cR1-preinstall
4. Update the System
yum update
My setup
groupadd --gid 54321 oinstall
groupadd --gid 54322 dba
groupadd --gid 54323 asmdba
groupadd --gid 54324 asmoper
groupadd --gid 54325 asmadmin
groupadd --gid 54326 oper
groupadd --gid 54327 backupdba
groupadd --gid 54328 dgdba
groupadd --gid 54329 kmdba
useradd --uid 54321 --gid oinstall --groups dba,oper,asmdba,asmoper,backupdba,dgdba,kmdba
oracle # passwd oracle
useradd --uid 54322 --gid oinstall --groups dba,asmadmin,asmdba,asmoper grid # passwd grid
2- systemctl disable firewalld
3-
/etc/selinux/config
4- yum install -y compat-libcap1 compat-libstdc++* glibc-devel* ksh libaio* libstdc++*
5- yum -y install rpm-build rpmdevtools wget
6- wget -
database-server-12cR2-preinstall-1.0-1.el7.src.rpm
7- I have created the RPM working directory tree:

$ rpm -ivh oracle-database-server-12cR2-preinstall-1.0-1.el7.src.rpm