Checkov

Checkov is a static code analysis tool for infrastructure-as-code (IaC) that scans cloud infrastructure provisioned using Terraform, CloudFormation, Kubernetes, Helm, ARM Templates and Serverless framework.

Installation

Using pip

pip install checkov

Using Homebrew

brew install checkov

Using Docker

docker pull bridgecrew/checkov

Basic Usage

Scan a Directory

checkov -d /path/to/terraform/code

Scan a Specific File

checkov -f /path/to/terraform/file.tf

Output Formats

# Output as JSON
checkov -d . --output json

# Output as JUnit XML
checkov -d . --output junitxml

# Output as SARIF
checkov -d . --output sarif

Configuration

Skip Checks

Create .checkov.yaml in your project root:

skip-check:
  - CKV_AWS_1  # Skip check for unencrypted S3 bucket
  - CKV_AWS_23 # Skip check for unencrypted RDS instance

skip-path:
  - terraform/examples/
  - tests/

framework:
  - terraform
  - kubernetes

Policy Categories

  1. Security

    • Access Control

    • Encryption

    • Network Security

    • IAM

  2. Compliance

    • HIPAA

    • PCI DSS

    • SOC2

    • NIST

  3. Operational Excellence

    • Backups

    • Monitoring

    • High Availability

CI/CD Integration

GitHub Actions

name: Checkov
on: [push, pull_request]

jobs:
  checkov:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Run Checkov
        uses: bridgecrewio/checkov-action@master
        with:
          directory: .
          framework: terraform
          output_format: sarif
          output_file: results.sarif
          soft_fail: true

Azure DevOps Pipeline

steps:
- script: |
    python -m pip install --upgrade checkov
    checkov -d . --output cli --quiet
  displayName: 'Run Checkov'

Pre-commit Hook

Add to .pre-commit-config.yaml:

repos:
- repo: https://github.com/bridgecrewio/checkov.git
  rev: '2.3.234'
  hooks:
    - id: checkov
      args: [--soft-fail]

Common Security Checks

1. S3 Bucket Security

# Secure configuration
resource "aws_s3_bucket" "compliant" {
  bucket = "my-secure-bucket"
  
  server_side_encryption_configuration {
    rule {
      apply_server_side_encryption_by_default {
        sse_algorithm = "AES256"
      }
    }
  }
  
  versioning {
    enabled = true
  }
  
  logging {
    target_bucket = aws_s3_bucket.log_bucket.id
    target_prefix = "log/"
  }
}

2. Security Group Rules

# Secure configuration
resource "aws_security_group" "compliant" {
  name = "compliant-sg"
  
  ingress {
    from_port   = 443
    to_port     = 443
    protocol    = "tcp"
    cidr_blocks = ["10.0.0.0/16"]
  }
  
  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

Custom Policies

Create custom_policies.py:

from checkov.common.models.enums import CheckResult, CheckCategories
from checkov.terraform.checks.resource.base_resource_check import BaseResourceCheck

class MyCustomCheck(BaseResourceCheck):
    def __init__(self):
        name = "Ensure custom tag exists"
        id = "CKV_CUSTOM_1"
        supported_resources = ['aws_instance']
        categories = [CheckCategories.CONVENTION]
        super().__init__(name=name, id=id, categories=categories, supported_resources=supported_resources)
    
    def scan_resource_conf(self, conf):
        if 'tags' in conf.keys():
            if 'CustomTag' in conf['tags'][0]:
                return CheckResult.PASSED
        return CheckResult.FAILED

Best Practices

  1. Regular Scanning

    • Integrate with CI/CD

    • Use pre-commit hooks

    • Schedule periodic scans

  2. Policy Management

    • Document skip decisions

    • Review skipped checks regularly

    • Maintain custom policies

  3. Remediation

    • Prioritize findings

    • Track fixes

    • Validate fixes

Checklist

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