Pros of Checkov

• Supports multiple IaC languages (Terraform, CloudFormation, Kubernetes, etc.)
• Extensive built-in policy library with 1000+ pre-defined checks
• Integrates with CI/CD pipelines and provides machine-readable output formats

Cons of Checkov

• May require more setup and configuration for custom policies
• Can be slower for large codebases due to its comprehensive scanning approach

Code Comparison

terraform-compliance/cli example:

Scenario: Ensure all EC2 instances have tags
  Given I have AWS EC2 instance defined
  Then it must contain tags
  And its value must not be null

Checkov example:

check = Check(check_id="CKV_AWS_1")
check.name = "Ensure all EC2 instances have tags"
check.supported_resources = ['aws_instance']
check.missing_attribute_result = CheckResult.FAILED

def check_resource(resource_conf):
    if 'tags' in resource_conf and resource_conf['tags']:
        return CheckResult.PASSED
    return CheckResult.FAILED

check.scan_resource_conf = check_resource

Both tools aim to ensure infrastructure compliance, but Checkov offers a more comprehensive approach with support for multiple IaC languages and a larger policy library. terraform-compliance focuses specifically on Terraform and uses a more human-readable, BDD-style syntax for defining checks.

Pros of tfsec

• Faster scanning speed, especially for large codebases
• Built-in support for custom rules using Rego language
• Integrates well with CI/CD pipelines and provides machine-readable output formats

Cons of tfsec

• Less flexible in terms of rule customization compared to terraform-compliance
• May produce more false positives in certain scenarios
• Lacks the ability to use Gherkin syntax for writing human-readable tests

Code Comparison

tfsec example:

resource "aws_s3_bucket" "my_bucket" {
  bucket = "my-bucket"
  acl    = "private"
}

terraform-compliance example:

Scenario: Ensure S3 buckets are private
  Given I have AWS S3 Bucket defined
  Then it must contain acl
  And its value must be private

Both tools aim to improve Terraform code security, but they approach the task differently. tfsec focuses on static analysis and predefined rules, while terraform-compliance offers more flexibility with its BDD-style syntax. The choice between them depends on specific project requirements and team preferences.

Pros of Terrascan

• Supports multiple IaC tools (Terraform, Kubernetes, Helm, Kustomize, Dockerfiles)
• Offers a wider range of built-in policies and security checks
• Provides a web UI for easier visualization and management of scan results

Cons of Terrascan

• May have a steeper learning curve due to its broader scope
• Can be more resource-intensive, especially for large-scale projects
• Less focused on Terraform-specific compliance checks

Code Comparison

Terrascan:

terrascan scan -i terraform -d /path/to/terraform/files

terraform-compliance:

terraform-compliance -p /path/to/terraform/plan.out -f /path/to/features

Key Differences

1. Scope: Terrascan is a multi-IaC tool, while terraform-compliance focuses solely on Terraform.
2. Policy Definition: Terrascan uses Rego language for policies, terraform-compliance uses Gherkin syntax.
3. Integration: terraform-compliance integrates more tightly with Terraform workflow, while Terrascan offers broader CI/CD integrations.
4. Community: terraform-compliance has a more active community specifically for Terraform users.
5. Customization: terraform-compliance allows for easier custom rule creation using natural language, while Terrascan requires more technical expertise for custom policies.

Both tools are valuable for ensuring IaC security and compliance, with the choice depending on specific project needs and team expertise.