Managing cloud resources has really changed with the Infrastructure as Code (IaC) approach, and Terraform has become one of the best tools for the job. But as things get more complicated, it can be difficult to keep your Terraform code clean, efficient and secure. Just as software developers use tools such as linters and documentation generators, infrastructure engineers also need specific tools to ensure that their Terraform code is ready for production.

In this article, I’ll cover a few important tools that can help you keep your Terraform code in good shape. I’ll cover areas such as static analysis, documentation, security checks and ways to improve your workflow. These tools can alert you early on to potential problems, help you adhere to best practices, stimulate teamwork and reduce operational risks.

1 — Static Analysis and Linting with TFLint

Image

What is TFLint?

TFLint is a powerful static analysis tool specifically designed for Terraform. Unlike Terraform’s built-in terraform validate command, which only checks syntax and basic structure, TFLint performs deeper analysis to identify potential errors, deprecated syntax, and provider-specific issues before you apply your infrastructure changes.

Key Benefits

  1. Provider-Specific Rules : TFLint includes rules tailored to major cloud providers like AWS, Azure, and GCP, catching issues such as using instance types that don’t exist in a specific region.
  2. Custom Rule Support : You can create organization-specific rules to enforce your internal standards and best practices.
  3. Integration with CI/CD Pipelines : TFLint can be easily integrated into your continuous integration workflows, preventing problematic code from reaching production.

Getting Started with Tflint

Installing TFLint is straightforward:

1
2
3
4
5
6
7
8

   # Using Homebrew on macOS
   brew install tflint

   # Using Chocolatey on Windows
   choco install tflint

   # Using curl
   curl -s <https://raw.githubusercontent.com/terraform-linters/tflint/master/install_linux.sh> | bash

Create a .tflint.hcl configuration file in your project root to customize rules:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19

    plugin "terraform" {
      enabled = true
      preset  = "recommended"
    }
    plugin "aws" {
        enabled = true
        version = "0.38.0"
        source  = "github.com/terraform-linters/tflint-ruleset-aws"
    }
    plugin "azurerm" {
        enabled = true
        version = "0.27.0"
        source  = "github.com/terraform-linters/tflint-ruleset-azurerm"
    }
    plugin "google" {
        enabled = true
        version = "0.31.0"
        source  = "github.com/terraform-linters/tflint-ruleset-google"
    }

Run TFLint regularly during development:

1

    tflint --recursive

Output:

Image Tflint output for the module https://github.com/Z4ck404/terraform-aws-eks-ebs-csi-driver

2 — Automated Documentation with terraform-docs

Image

What is terraform-docs?

Terraform-docs automatically generates documentation from your Terraform code, helping team members understand the purpose, inputs, outputs, and dependencies of your modules without having to manually maintain README files.

Key Benefits

  1. Consistent Documentation : Ensures all modules are documented in a standard format.
  2. Always Up-to-Date : Documentation is generated directly from code, eliminating drift between documentation and implementation.
  3. Multiple Output Formats : Supports Markdown, JSON, YAML, and other formats to fit different needs.

Getting Started with terraform-docs

Install terraform-docs:

1
2
3
4
5

    # Using Homebrew
    brew install terraform-docs

    # Using Go
    go install github.com/terraform-docs/terraform-docs@latest

Create a .terraform-docs.yml configuration file:

1
2
3
4
5
6
7
8

    formatter: "markdown table"

    output:
      file: "README.md"
      mode: inject

    settings:
      indent: 3

Generate documentation with:

1

    terraform-docs markdown . > README.md

The output : Image

For Git repositories, consider using pre-commit hooks to automatically update documentation before each commit.

3 — Security Scanning with Terrascan and Trivy

3.1 — Terrascan

Terrascan is an open-source security vulnerability scanner for Infrastructure as Code that detects compliance and security violations to mitigate risk before provisioning infrastructure.

Image

Key Features

  1. Comprehensive Policy Set : Includes hundreds of policies based on security best practices.
  2. Multiple IaC Support : Works with Terraform, Kubernetes, AWS CloudFormation, and more.
  3. Customizable Policies : Supports custom policies written in Rego (Open Policy Agent language).

Getting Started with terrascan

Install Terrascan:

1
2
3
4
5

    # Using Homebrew
    brew install terrascan

    # Using Docker
    docker pull accurics/terrascan

Run a scan:

1

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

3.2 — Trivy

Trivy is a comprehensive security scanner that can find vulnerabilities in container images, file systems, and configuration files including Terraform.

Image

Key Features

  1. Wide Coverage : Scans for vulnerabilities in infrastructure code, container images, and more.
  2. Misconfigurations Detection : Identifies security issues in Terraform configurations.
  3. Fast and Easy to Use : Simple setup with minimal configuration required.

Getting Started with trivy

Install Trivy:

1
2
3
4
5

    # Using Homebrew
    brew install trivy

    # Using apt
    apt-get install trivy

Scan Terraform files:

1

    trivy config --file-patterns "*.tf" /path/to/terraform/files

Additional Essential Tools for Production-Ready Terraform

1 — tfenv — Terraform Version Manager

tfenv is a simple yet powerful tool that solves the common challenge of managing multiple Terraform versions across different projects and teams. Version compatibility issues can lead to frustrating errors and inconsistent behavior, making tfenv an essential addition to any serious Terraform workflow.

Key Features

  1. Simple Version Management : Install, uninstall, and switch between Terraform versions with simple commands.
  2. Project-Specific Versions : Automatically use the correct Terraform version for each project using .terraform-version files.
  3. Easy Installation : Works on macOS, Linux, and Windows (via Windows Subsystem for Linux).

Getting Started with tfenv

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16

    # Install via Git
    git clone https://github.com/tfutils/tfenv.git ~/.tfenv
    echo 'export PATH="$HOME/.tfenv/bin:$PATH"' >> ~/.bash_profile

    # Or via Homebrew
    brew install tfenv

    # Install a specific Terraform version
    tfenv install 1.5.7

    # Use a specific version
    tfenv use 1.5.7

    # Auto-select version based on .terraform-version file
    echo "1.5.7" > .terraform-version
    tfenv install

Best Practices

  1. Version Pinning : Always specify the exact Terraform version in your .terraform-version file to ensure consistent behavior across all environments.
  2. CI/CD Integration : Configure your CI/CD pipelines to use tfenv to guarantee the correct Terraform version is used during automated deployments.
  3. Upgrade Testing : Use tfenv to test your Terraform configurations against new versions before officially upgrading.

A .terraform-version file in each project’s root directory allows tfenv to automatically switch to the appropriate version when you change directories, reducing the risk of applying infrastructure changes with an incorrect Terraform version.

2 — Checkov

Checkov is a static code analysis tool for infrastructure as code that scans cloud infrastructure configurations to find misconfigurations before they’re deployed.

Key Features

  1. Extensive Policy Library : Includes over 1,000 built-in policies.
  2. Custom Policies : Supports Python-based custom policies.
  3. Skip Mechanism : Allows you to skip specific checks with justification.

Getting Started

1
2

    pip install checkov
    checkov -d /path/to/terraform/files

3 — pre-commit Hooks

Pre-commit is a framework for managing and maintaining multi-language pre- commit hooks, which can automate formatting, linting, and documentation generation before code is committed.

Sample Configuration

Create a .pre-commit-config.yaml file:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16

    repos:
    - repo: https://github.com/pre-commit/pre-commit-hooks
      rev: v4.4.0
      hooks:
        - id: trailing-whitespace
        - id: end-of-file-fixer
        - id: check-yaml

    - repo: <https://github.com/antonbabenko/pre-commit-terraform>
      rev: v1.77.1
      hooks:
        - id: terraform_fmt
        - id: terraform_docs
        - id: terraform_tflint
        - id: terraform_validate
        - id: terraform_checkov

4 — Terragrunt

Terragrunt is a thin wrapper for Terraform that provides extra tools for working with multiple Terraform modules, fostering a DRY approach to Terraform code.

Key Features

  1. Configuration Reuse : Reduces repetition in Terraform configurations.
  2. Remote State Management : Simplifies backend configuration.
  3. Dependency Management : Handles dependencies between modules more elegantly.

Getting Started

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12

    # Install
    brew install terragrunt

    # Example structure
    /root
      terragrunt.hcl
      /dev
        terragrunt.hcl
      /staging
        terragrunt.hcl
      /prod
        terragrunt.hcl

5 — Infracost

Infracost shows cloud cost estimates for Terraform, helping engineers understand the financial implications of their infrastructure changes.

Image

Key Features

  1. Cost Breakdowns : Detailed breakdowns of resources and their estimated costs.
  2. CI/CD Integration : Can run in CI/CD pipelines to show cost differences in pull requests.
  3. Multiple Cloud Provider Support : Works with AWS, Azure, GCP, and more.

Getting Started

1
2
3
4
5
6
7
8
9

    # Install
    brew install infracost

    # Initialize with API key
    # Create an account first in https://www.infracost.io/
    infracost auth login

    # Generate cost estimate
    infracost breakdown --path /path/to/terraform

Image Infracost run against https://github.com/Z4ck404/aws-morocco-samples/tree/main/inter-region-privatelink

6 — Terraform Compliance

Terraform Compliance is a lightweight, compliance-focused test framework against Terraform that enables negative testing capability.

Key Features

  1. BDD-style Testing : Uses human-readable language for compliance rules.
  2. Focuses on Security : Specifically designed to enforce security and compliance requirements.
  3. CI/CD Integration : Can be integrated into CI/CD pipelines.

Example

1
2
3
4

    Feature: AWS S3 Bucket Security
      Scenario: Ensure S3 buckets have encryption enabled
        Given I have AWS S3 Bucket defined
        Then it must have encryption enabled

Integrating These Tools into Your Workflow

To get the most benefit from these tools, integrate them into your development workflow:

  1. Local Development : Use pre-commit hooks to ensure code quality before commits.
  2. CI/CD Pipeline : Run all tools during your CI process to catch issues before they reach production.
  3. Code Reviews : Use generated reports as part of the pull request review process.
  4. Regular Audits : Schedule comprehensive scans of your entire infrastructure codebase weekly or monthly.

A sample CI/CD pipeline stage might look like:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14

    terraform-quality:
      stage: validate
      script:
        - terraform init -backend=false
        - terraform validate
        - tflint
        - checkov -d .
        - terrascan scan -d .
        - terraform-docs markdown . > README.md
        - infracost breakdown --path .
      artifacts:
        paths:
          - README.md
          - infracost-report.html

Conclusion

In this article, we’ve looked at some practical tools that can help you keep your Terraform code in good shape. By using static analysis, automated documentation, security checks and cost estimation as part of your routine, you can catch errors early, meet your standards and keep your infrastructure safe and running smoothly.

By combining the right tools with code/infra best practices, you can create a sustainable infrastructure that’s scalable, secure and easy to manage.

What tools have you found useful on your Terraform journey? Please let me know in the comments! 💬

Terraform Infrastructure as Code: Essential Tools for Clean, MaintainableProduction Environments was originally published in AWSMorocco on Medium, where people are continuing the conversation by highlighting and responding to this story.