What is Terraform?

Table of Contents

How Terraform Works
Key Concepts
Example Snippet
Why Use Terraform with RELIANOID?
Resources

Terraform is an open-source Infrastructure as Code (IaC) tool that lets you declaratively provision and manage infrastructure across many providers (AWS, Azure, GCP, VMware, etc.). It enables repeatable, version-controlled environments.

How Terraform Works #

Configuration: You describe infrastructure in HCL files (resources, data sources, variables, outputs).
Providers: Plugins that translate configuration into API calls for each platform.
State: A state file tracks real resources and their attributes, enabling change detection (plan) and updates (apply).
Modules: Reusable units that encapsulate patterns and best practices.
Workflows: init → validate → plan → apply with remote state backends (e.g., S3, Azure Storage, GCS) and locking.

Key Concepts #

Idempotency: Running apply repeatedly converges resources to the declared state.
Dependency Graph: Terraform builds a DAG to order operations safely (create, update, destroy).
Immutability: Prefer replace-over-modify for safer rollouts.
Policy & CI/CD: Validate with fmt/validate, run plans in pipelines, and gate changes with code reviews.

Example Snippet #

# providers, variables, and modules omitted for brevity
resource "aws_instance" "relianoid_lb" {
  ami           = var.relianoid_ami_id
  instance_type = "c6i.large"
  subnet_id     = var.private_subnet_id
  user_data     = file("${path.module}/cloud-init-relianoid.yaml")
  tags = { Name = "relianoid-lb" }
}

Why Use Terraform with RELIANOID? #

Terraform lets you provision RELIANOID load balancers reproducibly across clouds and environments using the same Git-driven workflow:

Repeatability & audit: Versioned configuration ensures consistent LB instances, networks, and security rules across stages.
Multi-cloud standardization: One codebase to stand up RELIANOID on AWS, Azure, or GCP with environment-specific variables.
Reliable rollouts: Use plan to preview changes; apply with pipelines; leverage hot restart on RELIANOID to minimize disruption during policy updates.
Bootstrapping: Cloud-init or startup scripts can load initial RELIANOID configuration, certificates, and health checks at first boot.
Composability: Encapsulate listeners, pools, health probes, and security policies into reusable modules per application team.

With Terraform, your RELIANOID layer becomes part of the same audited, automated delivery process as the rest of your infrastructure.