Terraform Infrastructure as Code

Terraform is a free and open-source infrastructure as code (IaC) software tool that provides a consistent CLI workflow to manage hundreds of cloud services. Created by Mitchell Hashimoto and Armon Dadgar at HashiCorp in 2014, Terraform codifies cloud APIs into declarative configuration files, enabling developers and operations teams to provision, manage, and destroy infrastructure using a unified workflow. Key features: declarative configuration: infrastructure is defined in HashiCorp Configuration Language (HCL) or JSON files. Users describe the desired end state (resources and their properties), and Terraform determines how to achieve that state by comparing it with the current state and generating an execution plan. Providers: Terraform uses plugins called providers to interact with cloud platforms, SaaS services, and other APIs. Over 3,000 providers are available via the Terraform Registry, including AWS, Azure, Google Cloud, Kubernetes, Docker, GitHub, Datadog, Fastly, Cloudflare, and PostgreSQL. Resources: each provider defines resource types (aws_instance, azurerm_virtual_machine, google_compute_instance) and data sources (read-only resources). Resources have arguments, attributes, and lifecycle settings. State management: Terraform maintains a state file (terraform.tfstate) that maps configuration to real-world resources. State enables incremental updates. Remote state backends (S3, Azure Blob, Terraform Cloud) for team collaboration and state locking. Plan and apply: terraform plan generates a preview of changes, terraform apply executes them. Modules: reusable, versioned infrastructure packages. Module registry for sharing community modules. Variables and outputs for parameterization. Resource graph: Terraform builds a dependency graph and parallelizes non-dependent operations. Go. MPL-2.0.