Use one found here: http://www.vagrantbox.es you can use one of those to build upon or you can create one.
These steps are if you want to to create a fresh box.
Grab the latest CentOS image here:
I use the minimal image http://ftp.usf.edu/pub/centos/7.0.1406/isos/x86_64/CentOS-7.0-1406-x86_64-Minimal.iso
First you need to create a VM using Fusion.
- Select “Install from disc or image” >> Continue
- “Use another disc or disc image” >> Find your iso >> Continue
- Uncheck “Use Easy Install” make sure “Make your home folder accessible to the virtual machine is unchecked. >> Continue
- Click “Customize Settings” >> Rename your vm and place it somewhere safe.