Assessing Architecture Conformance to Coupling-Related Infrastructure-as-Code Best Practices: Metrics and Case Studies

Infrastructure as Code (IaC) is an IT practice that facilitates the management of the underlying infrastructure as software. It enables developers or operations teams to automatically manage, monitor, and provision resources rather than organize them manually. In many industries, this practice is widespread and has already been fully adopted. However, few studies provide techniques for evaluating architectural conformance in IaC deployments and, in particular, aspects such as loose coupling. This paper focuses on coupling-related patterns and practices such as deployment strategies and the structuring of IaC elements. Many best practices are documented in gray literature sources, such as practitioner books, blogs, and public repositories. Still, there are no approaches yet to automatically check conformance with such best practices. We propose an approach based on generic, technology-independent metrics tied to typical architectural design decisions for IaC-based practices in microservice deployments to support architecting in the context of continuous delivery practices. We present three case studies based on open-source microservice architectures to validate our approach.