The contrib/devstack/ directory contains the files necessary to integrate Rally with devstack.

To install:

$ DEVSTACK_DIR=.../path/to/devstack
$ cp lib/rally ${DEVSTACK_DIR}/lib
$ cp extras.d/70-rally.sh ${DEVSTACK_DIR}/extras.d

To configure devstack to run rally:

$ cd ${DEVSTACK_DIR}
$ echo "enable_service rally" >> localrc

Run devstack as normal:

$ ./stack.sh