Capture The Flag (CTF) competitions have established themselves as a highly effective pedagogical tool in cybersecurity education, offering students hands-on experience in realistic attack and defense scenarios. However, organizing and hosting these events requires considerable infrastructure effort, which frequently limits their adoption in academic settings. This paper presents the design, iterative development, and evaluation of a CTF as a Service (CaaS) platform built on Proxmox virtualization, leveraging Infrastructure as Code (IaC) tools such as Terraform and Ansible, container orchestration via Docker Swarm, and load balancing with HAProxy. The system supports both a development-centered workflow, in which challenges are automatically deployed from a Git repository through a CI/CD pipeline, and a deployment-oriented workflow for ad-hoc infrastructure provisioning. The paper describes the design decisions made, the challenges encountered during development, and the solutions implemented to achieve session persistence, external routing, and challenge replicability. The platform is designed to evolve into a CTF hosting service with commercial potential, and future lines of work are outlined regarding automatic scaling, monitoring integration, and frontend standardization.

翻译：“夺旗赛”（CTF）已成为网络安全教育中高效的教学工具，为学生提供真实攻击与防御场景的动手实践体验。然而，组织与举办此类赛事需要投入大量基础设施工作，这往往限制了其在学术环境中的推广。本文介绍了基于Proxmox虚拟化、结合基础设施即代码（IaC）工具（如Terraform与Ansible）、通过Docker Swarm进行容器编排、并利用HAProxy实现负载均衡的CTF即服务平台（CaaS）的设计、迭代开发与评估。该系统支持两种工作流：以开发为中心的工作流，即通过CI/CD管道自动从Git仓库部署挑战题目；以及面向部署的工作流，用于临时基础设施供应。本文阐述了设计决策、开发过程中遇到的挑战，以及为实现会话持久性、外部路由与挑战可复现性而实施的解决方案。该平台旨在发展为具备商业潜力的CTF托管服务，并规划了自动扩展、监控集成及前端标准化等未来研究方向。