Pros of Terraform

• Primary infrastructure-as-code tool for defining and provisioning infrastructure
• Extensive provider ecosystem for various cloud platforms and services
• Declarative language for describing desired infrastructure state

Cons of Terraform

• Not designed specifically for testing infrastructure code
• Lacks built-in testing frameworks or assertion capabilities
• Requires additional tools or custom scripts for comprehensive testing

Code Comparison

Terraform (main.tf):

resource "aws_instance" "example" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t2.micro"
}

Terratest (example_test.go):

func TestTerraformAwsExample(t *testing.T) {
  terraformOptions := &terraform.Options{
    TerraformDir: "../examples/terraform-aws-example",
  }
  defer terraform.Destroy(t, terraformOptions)
  terraform.InitAndApply(t, terraformOptions)
}

Key Differences

• Terraform focuses on infrastructure provisioning, while Terratest is specifically designed for testing infrastructure code
• Terratest provides a Go-based testing framework with built-in assertions and helper functions for infrastructure testing
• Terraform uses HCL (HashiCorp Configuration Language), whereas Terratest uses Go for writing tests
• Terratest can be used to test Terraform configurations, as well as other infrastructure-as-code tools

While Terraform is essential for defining and managing infrastructure, Terratest complements it by providing a robust testing framework for infrastructure code, ensuring reliability and correctness of deployments.

Pros of tflint

• Focused specifically on linting Terraform code, providing more specialized and in-depth checks
• Faster execution time for static code analysis
• Easier integration into CI/CD pipelines for continuous linting

Cons of tflint

• Limited to static code analysis, lacking the ability to perform actual infrastructure tests
• Does not support testing of deployed resources or infrastructure behavior
• Less comprehensive in terms of overall infrastructure validation

Code Comparison

tflint example:

resource "aws_instance" "example" {
  ami           = "ami-12345678"
  instance_type = "t2.micro"
}

Terratest example:

func TestAwsInstance(t *testing.T) {
    terraformOptions := &terraform.Options{
        TerraformDir: "../examples/terraform-aws-example",
    }
    defer terraform.Destroy(t, terraformOptions)
    terraform.InitAndApply(t, terraformOptions)
    instanceID := terraform.Output(t, terraformOptions, "instance_id")
    aws.AssertInstanceRunning(t, instanceID, "us-west-2")
}

While tflint focuses on static analysis of Terraform code, Terratest allows for actual deployment and testing of infrastructure. tflint is more suitable for quick syntax and best practice checks, while Terratest provides comprehensive infrastructure testing capabilities.

Pros of terraform-docs

• Focused specifically on generating documentation for Terraform modules
• Lightweight and easy to integrate into CI/CD pipelines
• Supports multiple output formats (Markdown, JSON, YAML, etc.)

Cons of terraform-docs

• Limited to documentation generation, lacks testing capabilities
• Does not provide infrastructure validation or deployment checks

Code comparison

terraform-docs:

# Generate Markdown documentation
terraform-docs markdown . > README.md

# Generate JSON documentation
terraform-docs json . > output.json

Terratest:

package test

import (
    "testing"
    "github.com/gruntwork-io/terratest/modules/terraform"
    "github.com/stretchr/testify/assert"
)

func TestTerraformModule(t *testing.T) {
    terraformOptions := &terraform.Options{
        TerraformDir: "../",
    }

    defer terraform.Destroy(t, terraformOptions)
    terraform.InitAndApply(t, terraformOptions)

    output := terraform.Output(t, terraformOptions, "example_output")
    assert.Equal(t, "expected_value", output)
}

Summary

terraform-docs is a specialized tool for generating documentation from Terraform modules, while Terratest is a comprehensive testing framework for infrastructure code. terraform-docs excels in simplicity and documentation generation, whereas Terratest offers robust testing capabilities for Terraform configurations.

Pros of Checkov

• Focuses on static code analysis and security scanning
• Supports multiple IaC languages (Terraform, CloudFormation, Kubernetes, etc.)
• Provides out-of-the-box policies and customizable rules

Cons of Checkov

• Limited to static analysis, doesn't perform actual infrastructure testing
• May produce false positives or miss runtime issues
• Requires separate integration for dynamic testing

Code Comparison

Checkov (policy-based scanning):

check = Check()

@check.check_resource("aws_s3_bucket")
def check_s3_bucket_encryption(resource):
    if "server_side_encryption_configuration" not in resource:
        return CheckResult.FAILED
    return CheckResult.PASSED

Terratest (infrastructure testing):

func TestS3BucketEncryption(t *testing.T) {
    bucketName := "my-test-bucket"
    aws.CreateS3Bucket(t, awsRegion, bucketName)
    defer aws.DeleteS3Bucket(t, awsRegion, bucketName)

    aws.AssertS3BucketEncrypted(t, awsRegion, bucketName)
}