Infrastructure as Code (IaC): A Complete Guide

The need for software development teams to create, test, and deploy applications quickly and efficiently has never been greater. Traditionally, setting up the infrastructure—like servers, databases, and storage—required manual processes and manual configuration, which was time-consuming and error-prone.

Infrastructure as Code (IaC) changes this by automating these tasks.

IaC is also an essential DevOps practice, indispensable to a competitively paced software delivery lifecycle. It enables IT operations teams to create and version infrastructure rapidly—like they version source code—and track these versions to avoid inconsistencies among IT environments that can lead to issues during deployment. This means that every environment, from development to production, is set up the same way, reducing the chance of unexpected problems and making it easier to manage and update the infrastructure.

This guide will explore IaC, its benefits, why IaC security is essential, and more. 

What is Infrastructure as Code? 

Infrastructure as Code is an IT practice that manages and provides computing infrastructure through machine-readable configuration files rather than physical hardware configuration or interactive configuration tools.

More simply stated, it’s a way to manage and set up your IT infrastructure using code, just like you would for software applications. Instead of manual infrastructure management—configuring servers, networks, and databases—you write scripts that automate these tasks. This makes creating, updating, and maintaining your infrastructure faster and more reliable. By treating infrastructure like code, teams can ensure consistency, reduce errors, and scale their systems more efficiently.

What are the Key Benefits of IaC? 

In essence, IaC transforms infrastructure management into a software engineering task, allowing teams to deploy and manage infrastructure using the tools and procedures they already use in application development. 

The main benefits of implementing IaC are this infrastructure automation and the efficiency that comes with it. When you automate the provisioning and management of infrastructure, you reduce the time and effort required for setup and maintenance.

Some other significant advantages of implementing Infrastructure as Code include:

• Consistency and reliability through ensuring that infrastructure is configured the same way every time, eliminating inconsistencies and reducing the risk of errors.
  
  
• Easy scaling of infrastructure to meet changing demands, enabling quick adaptation to business needs.
  
  
• Simple version control and tracking. Just like changes in the software core are easily tracked, IaC allows for easy auditing, rollbacks, and collaboration.
  
  
• Cost management and resource usage optimization by automating the creation and teardown of environments as needed, reducing idle resource costs.
  
  
• Improved security by embedding security configurations and policies in IaC scripts, ensuring consistent application of security best practices and easier compliance with regulations.
  
  
• Quick and reliable disaster recovery and infrastructure rebuilding in case of failure, ensuring minimal downtime and improved resilience.

IaC is a vital process in DevOps and DevSecOps because it allows these teams to efficiently create and operate multiple test environments. It also offers developers the flexibility to use different programming languages. This added flexibility lets teams concentrate on building, testing, and running high-quality applications more efficiently and cost-effectively.

However, the same features that make IaC advantageous can also introduce vulnerabilities into the infrastructure.

What Security Risks Are Commonly Associated with IaC?

The inter-connected and automated nature of IaC is both a benefit and its most significant security issue. This is especially true for misconfigurations. If one resource is misconfigured manually, the mistake should be easy to catch and remediate. However, the damage can be significant if one mistake in your code automatically provisions tens or even hundreds of resources. 

Misconfigurations can occur when IaC scripts have incorrect settings, such as open ports that should be closed, unencrypted data transmission configurations, or overly permissive security groups. These errors often stem from needing more expertise, oversight, or thorough testing.

IaC scripts can also contain vulnerabilities such as hard-coded credentials, insecure default configurations, or logical errors that expose infrastructure to attacks. 

According to a recent cloud threat report by Palo Alto Network’s Unit 42, 83% of organizations have hard-coded credentials in their version control management systems, and 85% have hard-coded credentials in virtual machines’ user data. The report also found that sensitive data lives in 66% of storage buckets and 63% of publicly exposed storage buckets. 

These vulnerabilities often arise from rushed development processes or a need for more secure coding practices.

Some other common security risks related to Infrastructure as Code include: 

• Lack of proper access controls: If IaC repositories are not adequately secured, unauthorized users may gain access to modify IaC scripts. This could happen due to insufficient access control policies or failure to enforce the principle of least privilege, leading to potential malicious changes to the infrastructure.

• Inadequate change management: Without proper version control and change management practices, changes to IaC scripts can go undocumented and unreviewed. This increases the likelihood of introducing insecure configurations as changes are not tracked, tested, or peer-reviewed before deployment.

• Dependency risks: IaC often relies on third-party modules and libraries. These dependencies can introduce vulnerabilities if they contain outdated or insecure code. Risks arise when dependencies are not regularly audited, updated, or adequately vetted for security issues.

• Insecure defaults: Some IaC tools or templates have insecure default settings not tailored to specific security requirements. If not identified and corrected before deployment, these insecure defaults can lead to vulnerabilities, often due to a lack of thorough review or understanding of the default settings.
  
  

Infrastructure as Code (IaC) Security Best Practices

To take advantage of the benefits of IaC, teams must prioritize keeping their systems secure and safeguarding their infrastructure. Continuous compliance is foundational to IaC security. All code, including code for provisioning cloud resources, must adhere to strict rules and standards. Some common security compliance controls that should be implemented include: 

• Code validation: Ensuring code is checked against integrated development environment (IDE) standards, threat models, and peer-reviewed before committing to the main repository.
  
  
• Automated pre-testing: Using pre-commit hooks and automated testing in sandboxed environments to validate code against stricter standards like Software Composition Analysis (SCA).
  
  
• Version control: Committing code to the source repository after validation. Before pushing to production, conduct additional compliance checks. This approach integrates compliance throughout the process.
  
  

It's also essential to minimize your cloud environment's attack surface. Some continuous risk assessment best practices include:

• Threat modeling: Using threat models to ensure up-to-date risk assessments are based on the latest security standards. Consider third-party services to jumpstart the process.
  
  
• Access control: Implementing least privilege access controls using tools like AWS IAM to limit permissions to what is necessary.
  
  
• Component monitoring: Paying particular attention to front-facing microservices, APIs, storage blocks, and computing engines. Reviewing and monitoring these components regularly to limit exposure to attacks.
  
  

Some other recommended IaC security practices include: 

• Data encryption at rest and in transit: Making sure that sensitive data, such as customer information and financial data, is encrypted by default. 
  
  
• Secure IDE plugins: Using tools like TFLint and Checkov to help in assessing IaC security and detecting potential risks early.  
  
  
• Secrets management: Storing secrets securely using vaults instead of plaintext files or SCMs like Git. Tools like HashiCorp Vault can manage and protect secrets.
  
  
• Static and Dynamic Analysis: Perform static and dynamic security scans and analysis of IaC scripts and deployed environments. 
  
  
• Tagging and inventory management: Properly tag and manage cloud assets to prevent untracked or "ghost" resources. Regularly review and audit these tags to maintain visibility and control.
  
  
• Runtime threat detection: Implementing solutions for runtime threat detection to monitor application behavior and detect threats in real time.
  
  
• Logging and monitoring: Enabling logging and monitoring to keep track of security events and assess risks. Tools like ELK Stack and Prometheus can aid log analysis and infrastructure monitoring.
  
  

Infrastructure as Code Tooling

Choosing the proper Infrastructure as Code solution is crucial for efficient and secure infrastructure management. When choosing tools, take into consideration your team's engineering capabilities, current use of cloud platforms, and integration with Continuous Integration/Continuous Delivery (CI/CD) platforms. 

Some popular IaC tools include:

• Terraform: A highly flexible IaC solution supporting multiple cloud providers and on-premise infrastructure through a vast provider ecosystem. It uses a declarative approach with its own language, HashiCorp Configuration Language (HCL), which is known for its readability. Terraform automatically handles dependency mapping between resources, ensuring the correct resource creation order. 

• Pulumi: This tool allows IaC using existing programming languages like TypeScript, JavaScript, Python, Go, and C#. This can be advantageous for teams with existing coding skills, as they can use familiar testing tools and practices.

• Microsoft Azure ARM Templates: The native IaC solution for Microsoft’s Azure cloud computing platform, using JSON format. The templates are well-documented and supported by Microsoft and immediately available for new Azure resources. 
  
  
• Amazon Web Services (AWS) CloudFormation: Amazon offers CloudFormation and the AWS Cloud Development Kit (CDK) for IaC. CloudFormation uses JSON or YAML for declarative templates and includes built-in state management. CDK allows IaC using familiar programming languages, taking an imperative approach. 

Reap the Benefits of IaC By Securing Your Systems Properly 

The use of cloud in DevOps is on the rise for obvious reasons, and IaC plays a crucial role in DevSecOps cloud security automation. Multiple tools can help you provision, organize, and manage infrastructure components and ease the IaC implementation process by automating many tasks and reducing errors that can be introduced through manual efforts. 

However, using these tools correctly is essential to secure your IaC implementation. By following best practices and leveraging these tools effectively, you can secure significant areas in your IaC initiatives. Additionally, integrating application security tools like Codacy, which offers SAST and DAST scans, gives software developers a unified set of security tools to eliminate risk from all angles.

Codacy scans Terraform, CloudFormation, and Kubernetes Infrastructure as Code for misconfigurations, protecting your IaC from the inside out. To see how it works, book a demo with us or start your free trial today.