The Bridge and the Blueprint: Providers & Resources

How a Request Travels

• Terraform
• ↓
• Provider (AWS)
• ↓
• AWS API
• ↓
• Creates Infrastructure

The Bridge

Without a provider, Terraform has no idea how to create an AWS EC2 instance, an Azure VM, a Docker container, or a GitHub repository. It's a plugin, downloaded during terraform init, that translates your configuration into real API calls.

The Blueprint

The resource block is what you actually want built — the EC2 instance, the S3 bucket, the VPC. Terraform reads it, compares it to current state, and creates, updates, or deletes accordingly.

Terraform Providers

Popular Providers

provider "aws" {
  region = "ap-south-1"
}

Region: Mumbai

This tells Terraform to use the AWS provider and create every AWS resource in this configuration inside the ap-south-1 region.

provider "azurerm" {
  features {}
}

provider "google" {
  project = "my-project"
  region  = "asia-south1"
}

Multiple Providers, One Project

provider "aws" {
  region = "ap-south-1"
}

provider "cloudflare" {}

• In one run, Terraform can create an AWS EC2 instance, a Cloudflare DNS record, a CloudFront distribution, and a Route53 zone — all coordinated from a single configuration.

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 6.0"
    }
  }
}

hashicorp/aws

Reads as Company / Provider — HashiCorp's own build of the AWS provider plugin.

~> 6.0

Means >= 6.0 and < 7.0 — accepts any patch or minor update within the 6.x line, never a breaking major version.

terminalAUTHENTICATION

$ export AWS_ACCESS_KEY_ID=xxxxxxxx
$ export AWS_SECRET_ACCESS_KEY=xxxxxxxx
# or
$ aws configure

Provider Lifecycle

• terraform init
• ↓ downloads provider
• terraform plan
• ↓ uses provider
• terraform apply
• ↓ calls cloud APIs

Terraform never stores credentials itself — it reads them from environment variables or your provider's own CLI configuration.

Terraform Resources

A resource is an infrastructure object Terraform creates and manages — an EC2 instance, an S3 bucket, a VPC, an RDS database, an IAM user, a security group, a Docker container. Everything you create in Terraform is, ultimately, a resource.

resource "<TYPE>" "<NAME>" { }

The type tells Terraform what kind of object to create; the name is a local label used only inside your configuration to reference it later.

resource "aws_instance" "web" {
  ami           = "ami-0123456789"
  instance_type = "t2.micro"
}

What You Set

Arguments tell Terraform what to create — inputs like instance_type, ami, or availability_zone. You write these directly into the resource block.

What You Get Back

After creation, Terraform knows values it couldn't have known beforehand — public IP, private IP, ARN, ID, DNS name. Reference them as aws_instance.web.public_ip.

resource "aws_instance" "web" {
  ami           = "ami-123456"
  instance_type = "t2.micro"

  tags = {
    Name = "WebServer"
  }
}

resource "aws_vpc" "main" {
  cidr_block = "10.0.0.0/16"
}

resource "aws_security_group" "web" {
  vpc_id = aws_vpc.main.id
}

resource "aws_vpc" "main" {}
resource "aws_subnet" "public" {}
resource "aws_instance" "web" {}

Resource Lifecycle

• terraform apply
• ↓
• Reads Configuration
• ↓
• Compares State
• ↓
• Creates / Updates / Deletes

Provider vs Resource

Provider + Resource Together

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 6.0"
    }
  }
}

provider "aws" {
  region = "ap-south-1"
}

resource "aws_instance" "web" {
  ami           = "ami-0123456789abcdef0"
  instance_type = "t3.micro"

  tags = {
    Name = "Terraform-Web-Server"
  }
}

How Terraform Processes This

• terraform init
• ↓ downloads AWS provider
• terraform plan
• ↓ reads aws_instance, calculates changes
• terraform apply
• ↓ AWS provider calls AWS API
• EC2 Instance Created