Policy enforcement using Congress

Policies are defined and evaluated in the Congress project. The policy language for Congress is Datalog. The congress policy consists of the Datalog rules and facts.

Examples of policies are as follows:

• Minimum 2 GB of RAM for all VM instances.

• A certified version for all Apache server instances.

• Data placement policy: all database instances must be deployed at a given geographic location enforcing some law restriction on data placement.

These policies are evaluated over data in the form of tables (Congress data structures). A deployed Murano environment must be decomposed to the Congress data structures. The decomposed environment is sent to Congress for simulation. Congress simulates whether the resulting state violates any defined policy: deployment is aborted in case of policy violation.

Murano uses two predefined policies in Congress:

• murano_system contains rules and facts of policies defined by the cloud administrator.

• murano contains only facts/records reflecting the resulting state after the deployment of an environment.

Records in the murano policy are queried by rules from the murano_system policy. The Congress simulation does not create any records in the murano policy, and only provides the feedback on whether the resulting state violates the policy or not.

As a part of the policy guided fulfillment, you need to enforce policies on a murano environment deployment. If the policy enforcement fails, the deployment fails as well.

This section contains the following subsections:

• Setting up policy enforcement
• Creating policy enforcement rules
• Murano policy enforcement internals
  • Model decomposition
• Using policy for the base modification of an environment
  • Creating base modification rules