Infrastructure as Code (IaC)#

Infrastructure as Code (IaC) is a methodology that treats infrastructure provisioning and management as code. In IaC, infrastructure components, such as servers, networks, databases, and their configurations, are defined and managed using code instead of manual processes or traditional configuration tools. This approach allows for the automation and consistent deployment of infrastructure, making it more predictable and scalable.

Advantages of Infrastructure as Code (IaC)#

Infrastructure as code brings many benefits, some of which are best realised in a cloud environment where machines are virtualised. IaC is certainly not only of use in the cloud, however – in the last few years it has rapidly gained popularity for managing critical physical infrastructure such as routers and switches. The main benefits are:

Automation

  • IaC eliminates many manual provisioning and configuration tasks, reducing human errors.

  • IaC enables rapid and consistent infrastructure deployment, speeding up development and testing cycles.

  • IaC facilitates the creation of repeatable and reliable infrastructure deployments – making scaling infrastructure much quicker and more accurate.

Consistency

  • IaC ensures that infrastructure configurations remain uniform across various environments.

  • Deploying infrastructure using IaC guarantees that development, testing, and production environments are identical, reducing compatibility issues.

  • IaC enhances security by enforcing consistent security policies and configurations across all infrastructure.

  • Infrastructure information stored as code can be easily backed up and restored if required.

Scalability

  • IaC allows for quick and efficient scaling of infrastructure resources to accommodate changing workloads – this is most beneficial in the cloud where new resources (for example, VMs) can be provisioned in minutes or seconds.

  • Storing infrastructure information in a template format is usually an important step in auto-scaling or enabling automatic resource provisioning based on demand, which optimizes cost and performance.

  • IaC simplifies capacity planning and resource management as infrastructures can scale both vertically and horizontally based on predefined criteria.

Tip: When deploying a development or testing environment with IaC it’s not uncommon for some changes to the environment to be made during the testing or development process. It’s critical that the IaC templates be adjusted to reflect these changes, otherwise, deployment to production may well fail!

Disadvantages of Infrastructure as Code (IaC)#

As with any newer approach, there are some drawbacks to IaC – in addition, like many services designed with the cloud in mind, IaC may have limited benefits for organisations using primarily physical equipment, or having only a small amount of infrastructure to begin with. Some issues to keep in mind include:

Learning Curve

  • IaC Requires teams to learn and adapt to new tools and practices, which can slow down initial implementation. In some cases, there can be resistance to new technology, particularly automation services.

  • May necessitate training and upskilling of existing personnel to effectively use IaC tools and frameworks. Properly managing IaC deployments is a skilled and specialised role.

  • Teams must stay updated with changes and updates in the IaC ecosystem, adding to the learning curve.

Complexity

  • As infrastructure configurations grow in complexity, managing and troubleshooting IaC code can become challenging.

  • Complex IaC codebases may be difficult to maintain, particularly without proper documentation and version control practices. Systems such as git can be hugely helpful in managing this, however, this requires further staff training.

  • Debugging IaC issues can be time-consuming, especially when dealing with intricate deployments.

Initial Setup

  • Setting up IaC workflows, pipelines, and toolchains may require an initial investment of time and resources (this may not be so much the case in the cloud)

  • Organizations must establish best practices, governance, and coding standards to ensure the effectiveness and reliability of IaC.

  • The process of transitioning from traditional infrastructure management to IaC can be resource-intensive, especially in legacy environments.

Tools Used to Implement Infrastructure as Code#

Several tools are commonly used to implement IaC. Here are a few popular ones -

Terraform#

Terraform is an open-source tool that allows you to define infrastructure configurations using HashiCorp Configuration Language (HCL) or JSON. It supports multiple cloud providers and on-premises infrastructure.

AWS CloudFormation#

AWS CloudFormation is a service-specific IaC tool for Amazon Web Services (AWS). It uses JSON or YAML templates to define AWS resource configurations.

Ansible#

Ansible is an automation tool that can be used for IaC. It uses YAML files called playbooks to define infrastructure configurations and automation tasks.

Puppet#

Puppet is an infrastructure automation tool that uses a declarative language to specify configurations. It is particularly suited for managing large-scale infrastructure.

Example of Infrastructure as Code (YAML)#

So what does IaC actually look like? - Here’s a simple YAML example of IaC for provisioning an AWS EC2 instance:

---
Resources:
  MyEC2Instance:
    Type: AWS::EC2::Instance
    Properties:
      InstanceType: t2.micro
      ImageId: ami-12345678
      KeyName: my-key-pair
      SecurityGroups:
        - my-security-group
      UserData: |
        #!/bin/bash
        echo "Hello, World! This is a user data script."
        # Additional provisioning steps can be included here.
      Tags:
        - Key: Name
          Value: MyInstance

The provided YAML example represents an Infrastructure as Code (IaC)template used for provisioning an Amazon EC2 instance within the Amazon Web Services (AWS) cloud environment. Within this IaC template, the Resources section serves as a declaration of the resources to be created or managed, with a specific focus on the creation of an EC2 instance. The logical name assigned to this instance is MyEC2Instance, enabling easy reference within the template. The Type field specifies the AWS resource type, indicating that an EC2 instance is being configured. The subsequent Properties section is where the configuration details for the EC2 instance are specified. Notably, it sets the instance type to a cost-effective t2.micro, specifies the Amazon Machine Image (AMI) to use, defines the key pair for secure access, associates a security group for network rules, includes a user data script for customization during instance launch, and assigns a tag for identification purposes. This IaC template encapsulates the infrastructure’s desired state, providing a blueprint for consistent and automated deployment while ensuring configuration control and version tracking, all of which are essential aspects of modern cloud-centric development and operations.

The Role of Infrastructure as Code in DevSecOps#

DevSecOps is an evolution of the DevOps philosophy that emphasizes the integration of security practices into the DevOps pipeline. It aims to break down traditional silos between development, security, and operations teams by embedding security throughout the entire software development and deployment lifecycle. In a DevSecOps culture, security isn’t seen as a separate phase but as an integral part of the development process - this approach fosters collaboration, automation, and a proactive stance on security.

IaC plays a pivotal role in DevSecOps by providing a systematic way to define and enforce security policies and best practices from the very beginning of the infrastructure provisioning process. By having a common language, or template style which is used to define infrastructure (for example, a document written in YAML) it’s much easier for operations and security specialists to “speak the same language” with a view to ensuring that both teams can optimise deployments per their own specialisms and goals. Here’s how IaC enhances security within a DevSecOps framework:

Security as Code#

In DevSecOps, security policies, compliance checks, and even vulnerability assessments can be codified as part of IaC templates. This means that security configurations are treated as code and are subject to the same version control, testing, and review processes as application code.

Continuous Security Testing#

IaC enables continuous security testing by allowing automated security scans and checks to be integrated into the development pipeline. This ensures that security is consistently evaluated throughout the development process.

Compliance and Audit Trail#

DevSecOps teams can leverage IaC to maintain a clear audit trail of infrastructure changes. This traceability aids in compliance with regulatory requirements and facilitates quick identification and remediation of security issues.

Rapid Response to Threats#

In the event of a security vulnerability or threat, IaC allows for rapid updates and redeployment of infrastructure with corrected configurations. This agility is crucial for responding promptly to emerging security risks.

Collaboration and Accountability#

IaC encourages collaboration between development, security, and operations teams. Security considerations are an integral part of the discussions and decisions made during the development process. This shared responsibility ensures accountability for security across the organization.

Final Words#

Infrastructure as Code is an approach which streamlines infrastructure management, enhances automation, and promotes consistency and scalability in cloud and on-premises environments. While there are challenges in adopting IaC, the benefits can often far outweigh the drawbacks, making it a valuable approach for modern IT and DevOps teams. This is especially the case in cloud environments, where it is easy to provision and de-provision virtual machines and resources with great speed and flexibility.