These packages are *optional* dependencies for salt. By default, they are not included in the salt RPMs.
Install any of these packages to enable the functionality within salt.

python-psutils
python-mysql
python-mako
python-pymongo
python-redis / redis

A semi-canonical list of the optional salt modules can be found at
https://github.com/saltstack/salt/blob/develop/doc/conf.py#L30
