Congress is an open policy framework for the cloud. With Congress, a cloud operator can declare, monitor, enforce, and audit "policy" in a heterogeneous cloud environment. Congress gets inputs from a cloud's various cloud services; for example in OpenStack, Congress fetches information about VMs from Nova, and network state from Neutron, etc. Congress then feeds input data from those services into its policy engine where Congress verifies that the cloud's actual state abides by the cloud operator's policies. Congress is designed to work with any policy and any cloud service.
Please refer to the installation guide