Terraform (HashiCorp)

Terraform is an infrastructure as code tool for building, changing and versioning infrastructure safely and efficiently, covering low-level components such as compute instances, storage and networking alongside high-level ones including DNS entries and SaaS features. HashiCorp publishes hands-on tutorials and a sandbox environment with preinstalled tools for experimenting with it.

Covering SaaS configuration as well as cloud infrastructure is the property that changed how the tool is used. Declaring a DNS record, a monitoring alert or a repository setting in the same file as the servers means the whole environment is described in one place, and the boundary between infrastructure and configuration stops mattering.

Versioning is the word doing the real work in the description. Infrastructure defined in files that live in source control can be reviewed, reverted and audited like application code, which is what turns a change to production from an action somebody took into a change somebody approved.

The provider ecosystem is what makes any of this possible and is worth checking for anything unusual. Terraform manages whatever a provider exists for, so the practical question during evaluation is whether the systems you actually run are covered.