Harness is a Continuous Deployment platform that allows automating the deployment of software to infrastructure and environments. To set up a private Cloudsmith repository as an artifact source for a Harness pipeline, users log into the Harness Manager, navigate to "Setup", and configure the Cloud Provider, Connectors, and Applications. The user adds their Cloudsmith registry URL, username, encrypted password, and Cloudsmith API key as an encrypted secret. They define an Application with Services, Environments, Workflows, Pipelines, Triggers, and Infrastructure Provisioners, including deploying a docker image to AWS ECS. After creating a pipeline that runs a workflow, the user pushes a docker image to their Cloudsmith repository and sets up a trigger to start the pipeline when a new artifact is pushed. Once the pipeline executes, it deploys the docker image to AWS ECS successfully.