Terraform File Generator

Overview

This project provides a PowerShell script that dynamically generates Terraform configuration files (main.tf, variables.tf, and outputs.tf) based on JSON input. This approach streamlines the process of creating Terraform files, making infrastructure management more efficient and less error-prone.

Features

• Automates Terraform file creation: Generates main.tf, variables.tf, and outputs.tf files dynamically.
• JSON-based input: Uses a JSON file to define the provider, resources, variables, and outputs.
• Module-based approach: Ensures consistency and reduces manual errors by following a predefined pattern.

Prerequisites

• PowerShell: Ensure PowerShell is installed on your system.
• Terraform: Basic knowledge of Terraform and its configuration files.

Usage

Step 1: Prepare JSON Input

Create a JSON file (e.g., example.json) with the necessary configuration details. Below is a sample JSON structure:

{
    "provider": {
        "name": "aws"
    },
    "variables": [
        {
            "name": "region",
            "description": "The AWS region to deploy in",
            "type": "string",
            "default": "us-west-2"
        },
        {
            "name": "instance_type",
            "description": "The type of instance to use",
            "type": "string",
            "default": "t2.micro"
        },
        {
            "name": "instance_name",
            "description": "The name of the instance",
            "type": "string",
            "default": "ExampleInstance"
        }
    ],
    "resources": [
        {
            "type": "aws_instance",
            "name": "example",
            "properties": {
                "ami": "var.ami",
                "instance_type": "var.instance_type"
            }
        }
    ],
    "outputs": [
        {
            "name": "instance_id",
            "description": "The ID of the EC2 instance",
            "value": "aws_instance.example.id"
        },
        {
            "name": "public_ip",
            "description": "The public IP of the EC2 instance",
            "value": "aws_instance.example.public_ip"
        }
    ]
}

Step 2: Run the PowerShell Script

Save the PowerShell script below as main.ps1:

param (
    [string]$jsonInput
)

function New-MainTf {
    param (
        $data
    )

    $provider = $data.provider
    $resources = $data.resources

    $providerBlock = @"
provider "$($provider.name)" {
  region = var.region
}`n
"@

    $resourcesBlock = ""

    foreach ($resource in $resources) {
        $resourceBlock = @"
resource "$($resource.type)" "$($resource.name)" {
"@
        foreach ($key in $resource.properties.Keys) {
            $resourceBlock += "  $key = $($resource.properties.$key)`n"
        }
        $resourceBlock += @"
`n  tags = {
    Name = var.instance_name
  }
}`n
"@ 
        $resourcesBlock += $resourceBlock
    }

    $content = $providerBlock + $resourcesBlock
    Set-Content -Path ".\main.tf" -Value $content
}

function New-VariablesTf {
    param (
        [PSCustomObject]$data
    )

    $variables = $data.variables

    $variablesBlock = ""

    foreach ($var in $variables) {
        $default = if ($var.ContainsKey('default')) { "  default     = `"$($var.default)`"" } else { "" }
        $variableBlock = @"
variable "$($var.name)" {
  description = "$($var.description)"
  type        = $($var.type)
$default
}`n
"@
        $variablesBlock += $variableBlock
    }

    Set-Content -Path ".\variables.tf" -Value $variablesBlock
}

function New-OutputsTf {
    param (
        [PSCustomObject]$data
    )

    $outputs = $data.outputs

    $outputsBlock = ""

    foreach ($output in $outputs) {
        $outputBlock = @"
output "$($output.name)" {
  description = "$($output.description)"
  value       = $($output.value)
}`n
"@
        $outputsBlock += $outputBlock
    }

    Set-Content -Path ".\outputs.tf" -Value $outputsBlock
}

function Main {
    param (
        $jsonInput
    )

    $data = $jsonInput | ConvertFrom-Json
    New-MainTf -data $data
    New-VariablesTf -data $data
    New-OutputsTf -data $data
    Write-Output "Terraform files have been generated successfully."
}

Read the JSON input file
$jsonInput = Get-Content -Path ".\example.json"
Main -jsonInput $jsonInput

Result

Upon execution, the script will generate the following Terraform configuration files in the same directory:

• main.tf
• variables.tf
• outputs.tf#