What questions do programmers ask about configuration as code?

Configuration as code (CaC) tools, such as Ansible and Puppet, help software teams to implement continuous deployment and deploy software changes rapidly. CaC tools are growing in popularity, yet what challenges programmers encounter about CaC tools, have not been characterized. A systematic investigation on what questions are asked by programmers, can help us identify potential technical challenges about CaC, and can aid in successful use of CaC tools. The goal of this paper is to help current and potential configuration as code (CaC) adoptees in identifying the challenges related to CaC through an analysis of questions asked by programmers on a major question and answer website. We extract 2,758 Puppet-related questions asked by programmers from January 2010 to December 2016, posted on Stack Overflow. We apply qualitative analysis to identify the questions programmers ask about Puppet. We also investigate the trends in questions with unsatisfactory answers, and changes in question categories over time. From our empirical study, we synthesize 16 major categories of questions. The three most common question categories are: (i) syntax errors, (ii) provisioning instances; and (iii) assessing Puppet's feasibility to accomplish certain tasks. Three categories of questions that yield the most unsatisfactory answers are (i) installation, (ii) security, and (iii) data separation.