Biblio

The increasing use of Infrastructure as Code (IaC) in DevOps leads to benefits in speed and reliability of deployment operation, but extends to infrastructure challenges typical of software systems. IaC scripts can contain defects that result in security and reliability issues in the deployed infrastructure: techniques for detecting and preventing them are needed. We analyze and survey the current state of research in this respect by conducting a literature review on static analysis techniques for IaC. We describe analysis techniques, defect categories and platforms targeted by tools in the literature.

An experimental network environment plays an important role to examine new systems and protocols. We have developed an experimental network construction tool called LiONv1 (Lightweight On-Demand Networking, ver.1). LiONv1 satisfies the following four requirements: programmer-friendly configuration file based on Infrastructure as Code, multiple virtualization technologies for virtual nodes, physical topology conscious virtual node placement, and L3 protocol agnostic virtual networks. None of existing experimental network environments satisfy all the four requirements. In this paper, we develop LiONv2 which satisfies three more requirements: diversity of available network devices, Internet-scale deployment, and disaggregation of network configuration and device configuration. LiONv2 employs NETCONF and YANG to achieve diversity of available network devices and Internet-scale deployment. LiONv2 also defines two YANG models which disaggregate network configuration and device configuration. LiONv2 is implemented in Go and C languages with public libraries for Go. Measurement results show that construction time of a virtual network is irrelevant to the number of virtual nodes if a single virtual node is created per physical node.

Defects in infrastructure as code (IaC) scripts can have serious
consequences, for example, creating large-scale system outages. A
taxonomy of IaC defects can be useful for understanding the nature
of defects, and identifying activities needed to fix and prevent
defects in IaC scripts. The goal of this paper is to help practitioners
improve the quality of infrastructure as code (IaC) scripts by developing
a defect taxonomy for IaC scripts through qualitative analysis.
We develop a taxonomy of IaC defects by applying qualitative analysis
on 1,448 defect-related commits collected from open source
software (OSS) repositories of the Openstack organization. We conduct
a survey with 66 practitioners to assess if they agree with the
identified defect categories included in our taxonomy. We quantify
the frequency of identified defect categories by analyzing 80,425
commits collected from 291 OSS repositories spanning across 2005
to 2019.

Our defect taxonomy for IaC consists of eight categories, including
a category specific to IaC called idempotency (i.e., defects that
lead to incorrect system provisioning when the same IaC script is
executed multiple times). We observe the surveyed 66 practitioners
to agree most with idempotency. The most frequent defect category
is configuration data i.e., providing erroneous configuration data
in IaC scripts. Our taxonomy and the quantified frequency of the
defect categories may help in advancing the science of IaC script
quality.

Practitioners use infrastructure as code (IaC) scripts to provision servers and development environments. While developing IaC scripts, practitioners may inadvertently introduce security smells. Security smells are recurring coding patterns that are indicative of security weakness and can potentially lead to security breaches. The goal of this paper is to help practitioners avoid insecure coding practices while developing infrastructure as code (IaC) scripts through an empirical study of security smells in IaC scripts. We apply qualitative analysis on 1,726 IaC scripts to identify seven security smells. Next, we implement and validate a static analysis tool called Security Linter for Infrastructure as Code scripts (SLIC) to identify the occurrence of each smell in 15,232 IaC scripts collected from 293 open source repositories. We identify 21,201 occurrences of security smells that include 1,326 occurrences of hard-coded passwords. We submitted bug reports for 1,000 randomly-selected security smell occurrences. We obtain 212 responses to these bug reports, of which 148 occurrences were accepted by the development teams to be fixed. We observe security smells can have a long lifetime, e.g., a hard-coded secret can persist for as long as 98 months, with a median lifetime of 20 months.