Lightweight WLCG sites: The SIMPLE Grid Framework

This article describes a new framework, called SIMPLE, for settingup and maintaining classic WLCG sites with minimal operational efforts and insights needed into the WLCG middleware. The framework provides a single common interface to install and configure any of its supported grid services, such as Compute Elements, Batch Systems, Worker Nodes and miscellaneous middleware packages. It leverages modern container orchestration tools like Kubernetes, Docker Swarm, and confiuration management tools like Puppet, Ansible, to automate deployment of the WLCG services on behalf of a site admin. The framework is modular and extensible by design. Therefore, it is easy to add support for more grid services as well as infrastructure automation tools to accommodate diverse scenarios at different sites. We provide insight into the design of the framework and our efforts towards development, release and deployment of its first implementation featuring CREAM E, TORQUE Batch System and TORQUE based Worker Nodes.