What Do Infrastructure-as-Code Practitioners Discuss: An Empirical Study on Stack Overflow

Background. Infrastructure-as-Code (IaC) is an emerging practice to manage cloud infrastructure resources for software systems. Modern software development has evolved to embrace IaC as a best practice for consistently provisioning and managing infrastructure using various tools such as Terraform and Ansible. However, recent studies highlighted that developers still encounter various challenges with IaC tools. Aims. We aim in this paper to understand the different challenges that developers encounter with IaC and analyze the trend of seeking assistance on Q&A platforms in the context of IaC. To this end, we conduct a large-scale empirical study investigating developers' discussions in Stack Overflow. Method. We first collect IaC-relevant tags on Stack Overflow, constituting a dataset that comprises 52,692 questions and 64,078 answers. Then, we group questions into specific topics using the Latent Dirichlet Allocation (LDA) method, which we optimize using a Genetic Algorithm (GA) for parameter's fine-tuning. Finally, to gain better insights, we analyze the identified topics based on different criteria such as popularity and difficulty. Results. Our findings reveal an average yearly increase of 150% in terms of IaC-related questions and 135% in terms of users between 2011 and 2022. Furthermore, we observe that IaC questions revolve around seven main topics: server configuration, policy configuration, networking, deployment pipelines, variable management, templating, and file management. Notably, we found that server configuration and file management are the most popular topics, i.e., the most discussed among IaC developers, while the deployment pipelines and templating topics are the most difficult. Conclusions. Our results shed light on IaC challenges that are often encountered by developers on popular Q&A platforms. These findings reveal important implications for practitioners seeking better support for IaC tools in real-world settings and for researchers to better understand the IaC community needs and further investigate IaC in different aspects.