Infrastructure as Code is often associated with "Continuous Configuration Automation." We think the term should be "Continual Configuration Automation."
There are four popular tools to rapidly provision cloud infrastructure using templates: Azure Resource Manager, CloudFormation, Terraform, and Heat. Three of these tools each support two different types of template files for provisioning servers.
- Azure Resource Manager uses JSON exclusively (as our research indicates as of November of 2017).
- CloudFormation can use JSON (CFN, aka CloudFormation, templates) or YAML to create virtual servers architected to work together. For an article about moving away from JSON to YAML for AWS CloudFormation, see this link.
- Hashicorp's Terraform can use JSON or HashiCorp Configuration Language. See this link for more information.
- Heat uses either JSON (CFN templates) or YAML (Heat Orchestration Templates). For more information, see this link.