I tried by following the instructions described here but they don't work. It looks like the repository mentioned in those instructions is actually not working:
http://fedora.vitu.ch/QGIS/7/x86_64/repodata/repomd.xml: [Errno 14]
HTTP Error 404 – Not Found
I was unable to find any other working method. This other repo I was able to find only goes up to CentOS 6: http://elgis.argeo.org/
Best Answer
I used the following to successfully install QGIS with Python Plugin support on a CentOS 7 minimal install:
Install a GUI Desktop
yum groupinstall "GNOME Desktop"
Install QGIS+Python Support and supporting packages
yum install qgis qgis-python python-devel PyQt4-webkit proj-devel geos-devel sqlite-devel gcc
Python Requirement: Python 2.7 comes standard in CentOS 7
Install pip
wget https://bootstrap.pypa.io/get-pip.py
python get-pip.py
Install pyspatialite (including /usr/include libraries)
CFLAGS=-I/usr/include pip install pyspatialite