Terraform Module with for_each INSIDE Module (Azure RG)

 Terraform Module with for_each INSIDE Module (Azure RG)

#!/bin/bash

# Create directory structure
mkdir -p tfmodule-foreach-inside/modules/rg
cd tfmodule-foreach-inside || exit

echo "📁 Creating Terraform files..."

# -------------------------
# provider.tf
# -------------------------
cat <<EOF > provider.tf
provider "azurerm" {
  features {}
}
EOF

# -------------------------
# main.tf (NO loop here)
# -------------------------
cat <<EOF > main.tf

module "rg" {
  source = "./modules/rg"

  resource_groups = {
    dev  = "rg-dev"
    test = "rg-test"
    prod = "rg-prod"
  }

  rg_location = "eastus"
}

output "rg_names_output" {
  value = module.rg.rg_names_output
}
EOF

# -------------------------
# modules/rg/rg.tf (for_each HERE)
# -------------------------
cat <<EOF > modules/rg/rg.tf
resource "azurerm_resource_group" "rg" {
  for_each = var.resource_groups

  name     = each.value
  location = var.rg_location

  tags = {
    environment = each.key
  }
}
EOF

# -------------------------
# modules/rg/variable.tf
# -------------------------
cat <<EOF > modules/rg/variable.tf
variable "resource_groups" {
  type = map(string)
}

variable "rg_location" {
  type = string
}
EOF

# -------------------------
# modules/rg/output.tf
# -------------------------
cat <<EOF > modules/rg/output.tf
output "rg_names_output" {
  value = {
    for key, rg in azurerm_resource_group.rg :
    key => rg.name
  }
}
EOF

echo "✅ Terraform module with for_each INSIDE module created!"
echo ""
echo "👉 Next steps:"
echo "cd tfmodule-foreach-inside"
echo "terraform init"
echo "terraform plan"
echo "terraform apply"

---

▶️ How to Run

chmod +x setup.sh
./setup.sh

---

🎯 What This Does

• Module called once
• for_each inside module creates:
  • rg-dev
  • rg-test
  • rg-prod

---

📤 Output Example

{
  "dev": "rg-dev",
  "test": "rg-test",
  "prod": "rg-prod"
}

---

🧠 Key Concept (Very Important)

🔹 for_each inside module

• Loops over map
• Uses:
  • each.key → dev/test/prod
  • each.value → resource name

---

⚖️ Count vs for_each (Inside Module)

Feature	count	for_each
Input type	list	map
Stability	❌ index-based	✅ key-based
Production use	⚠️ limited	✅ recommended

---

✅ Summary

• for_each inside module = best practice
• Cleaner, stable, production-ready
• Ideal for multi-environment setups