Just to make sure:
sudo yum update
Get the YUM package:
sudo curl -o /etc/yum.repos.d/mssql-server.repo https://packages.microsoft.com/config/rhel/7/mssql-server-2017.repo
Install MS SQL:
sudo yum install -y mssql-server
Setup server:
sudo /opt/mssql/bin/mssql-conf setup
Open network firewall for 1433 (default port for MSSQL) so that it could be accessed from other machine.
sudo firewall-cmd --zone=public --add-port=1433/tcp --permanent
sudo firewall-cmd --reload
Done.