STC is a developer oriented framework for testing and debugging running ONOS clusters. It allows modular definition and composition of test scenarios, as well as reuse of test modules. Developers can use scenarios in a semi-automated or fully automated manner. STC tracks dependencies between scenarios and allows parallel execution of steps that don't depend on each other to improve performance and to allow modeling concurrent activities like running a step on each node in a cluster. Larger scenarios can be built up from smaller scenarios allowing reuse of tests. STC is integrated into the cell framework and can be used to deploy and test on a cell.

Key Concepts and Terminology

• cell - definition of a set of resources used to run an ONOS cluster
• STC - framework for execution and verification of scenarios
• scenario - a reusable logical grouping of steps to accomplish some task
• step - a single unit of execution within a scenario. A step can be a call to bash, python, or other executable. Steps define an action and an expected outcome.

Predefined Scenarios

STC comes with a set of predefined scenarios designed to test specific ONOS behavior. The most commonly used scenarios are:

• stc setup - pushes a build of ONOS from the host onto all nodes of the cell. Once the bits have been pushes, ONOS is started and STC verifies that all nodes are up and in their basic configuration, and that no errors occurred. 
• stc net-setup - creates a mininet instance and standard topology on a running ONOS cluster
• stc fast - runs a set of smoke tests that complete quickly, testing reactive forwarding and basic connectivity
• stc smoke (or just stc) - runs a more involved set of smoke tests, testing intents, flows, flow objectives, drivers, and apps

Running STC

STC is run from a command line shell. If you have a properly configured development environment and cell, stc will run the tests for you and display the results of the test run. Here is an example of how to run the fast smoke test on a cell with one controller and one mininet node.