1. A method comprising: receiving configuration instructions for elements of a network topology to be simulated and tested; configuring via an Application Programming Interface (API), in response to receiving and in accordance with the configuration instructions, a plurality of software images running in a cloud host for a plurality of virtual network elements in the network topology; configuring via the API, in response to receiving and in accordance with the configuration instructions, data representing one or more connections between the virtual network elements; and executing the plurality of software images for the plurality of virtual network elements in accordance with the data representing the connections, for development and testing of the network topology.