yum install fontconfig libXrender libXext xorg-x11-fonts-Type1 xorg-x11-fonts-75dpi freetype libpng zlib libjpeg-turbo
rpm -Uvh wkhtmltox-0.12.2.1_linux-centos7-amd64.rpm
wkhtmltopdf http://www.google.com google.pdf
Allow apache to exicute an external program through SELinux.
here it is https://downloads.wkhtmltopdf.org/0.12/0.12.2.1/wkhtmltox-0.12.2.1_linux-centos7-amd64.rpm