Network controller as a service (ncaas) to define network policies for third-party container clusters

A non-transitory machine readable medium storing a program for execution by at least one processing unit for using a first software defined networking (SDN) controller cluster as a network controller as a service (NCaaS) to define a particular set of network policies to enforce in a plurality of container clusters, the program comprising sets of instructions for:

• at the first SDN controller cluster that provides the network controller as a service:
• receiving a first set of network attributes regarding a first set of network elements in a first container cluster that is configured by a second SDN controller cluster and does not have a controller cluster in the first container cluster for defining the particular set of network policies;
• receiving a second set of network attributes regarding a second set of network elements in a second container cluster that is configured by a third SDN controller cluster and does not have a controller cluster in the second container cluster for defining the particular set of network policies;
• based on the first and second sets of network attributes, defining the particular set of network policies to control forwarding data messages between the first and second container clusters;
• and
• distributing at least a subset of the defined network policies to the first container cluster in order for at least one of the first set of network elements at the first container cluster to enforce on data messages exchanged between the first and second container clusters.