What is IAC?

IaC automates the provisioning and management of infrastructure through code, drastically reducing the manual labor involved in configuring and maintaining resources. This is typically achieved through either a declarative or an imperative approach.

Declarative (functional) approach: This method involves defining the desired state of the infrastructure, but not the steps to get there. The IaC tooling then automatically makes the necessary changes to achieve this state.

Here’s an example of declarative IaC code:

Resource: WebServer
Type: AWS::EC2::Instance
Properties:
  ImageId: "ami-0abcdef1234567890"
  InstanceType: t2.micro
  SecurityGroups:
    - WebServerSG
  KeyName: MyKeyPair

In this example, the desired state is defined for an AWS EC2 instance. It specifies what the final configuration should look like, including the instance type, image ID, security groups, and key pair, but not how to create it.

Imperative (procedural) approach: Here, the specific commands and steps needed to achieve the desired end-state are defined.

create_security_group(name: "WebServerSG")
create_key_pair(name: "MyKeyPair")
instance_id = create_instance(image_id: "ami-0abcdef1234567890", instance_type: t2.micro)
assign_security_group(instance_id: instance_id, group_name: "WebServerSG")
assign_key_pair(instance_id: instance_id, key_name: "MyKeyPair")

In this example, each step in setting up an EC2 instance is explicitly stated: creating a security group, creating a key pair, launching an instance, and then assigning the security group and key pair to the instance.

Choosing between declarative and imperative IaC usually comes down to the level of flexibility or precision required for your project:

• A team might choose a declarative IaC approach for its simplicity in defining a specific end state of the infrastructure without the need to script the exact steps to achieve it, which is particularly helpful for managing large-scale and complex environments.

• The imperative approach is often preferred for use cases requiring finer control and specificity in the setup process, such as specialized research environments or applications with strict compliance requirements.

Whether you use a declarative or an imperative approach to IaC, the core of IaC lies in its ability to read these configuration files and translate them into actions that set up the infrastructure as defined.

Once a configuration file is written, it is fed into an IaC tool that parses the configuration files, understands the desired state of the infrastructure as defined in them, and makes API calls or executes commands to bring the actual infrastructure in line with this state. This process is repeatable and idempotent, meaning that executing the configuration multiple times results in the same state of the infrastructure, ensuring consistency and reliability in the infrastructure setup.

Adopting IaC offers many advantages:

• Consistency and reproducibility: Defining infrastructure configurations as code ensures that your infrastructure is reproducible and consistent across environments. It allows you to easily recreate and share exactly the same infrastructure setup for development, testing, and production. This reduces the likelihood of configuration drift and makes it easier to maintain and troubleshoot infrastructure.

• Version control and change tracking: IaC uses version control systems like Git to manage infrastructure code. Version control ensures that every change to the infrastructure is documented, and that you can review the history of changes to understand who made the modifications and when. This audit trail is invaluable for compliance, debugging, and maintaining a secure and stable infrastructure.

• Scalability and automation: IaC enables you to automate the provisioning and scaling of infrastructure resources. Through code, you can define how your infrastructure should expand or contract based on demand. This scalability and automation works hand-in-hand with Agile methodologies, allowing your organization to respond efficiently to changing requirements with minimal manual intervention.

• Efficiency and cost-effectiveness: IaC significantly enhances operational efficiency by allowing teams to easily replicate and deploy complex infrastructure in a matter of minutes. IaC also enables you to optimize resource allocation and scaling strategies, eliminating over-provisioning and reducing unnecessary costs. This cost-effectiveness is especially valuable in the cloud, where paying for unused resources can quickly add up. IaC empowers teams to fine-tune their infrastructure, ensuring that resources are allocated judiciously to meet performance requirements while minimizing expenses.

IaC relies on a set of tools and technologies that help manage IT infrastructure. These tools fall into several categories, each serving a specific purpose in the IaC workflow:

Configuration management: These tools are used to define and manage the state of your infrastructure, configuring servers, applications, and other resources to match the defined specifications. Examples include Ansible, Puppet, and Chef.

Orchestration and provisioning: These tools spin up servers, virtual machines, databases, and other resources as defined in your IaC code. Common tools in this category include Terraform, AWS CloudFormation, and Azure Resource Manager templates.

Version control: Git, along with platforms like GitHub or GitLab, is fundamental for IaC development and collaboration. It allows teams to manage and track changes to infrastructure code, collaborate effectively, and maintain a history of modifications.

Continuous integration/continuous deployment (CI/CD): CI/CD automates the building, testing, and deployment of infrastructure code. It helps ensure that changes to your IaC code are tested thoroughly and deployed consistently across different environments.

Learn more about CI/CD

Cloud services: Major cloud providers offer their own IaC solutions, such as AWS CloudFormation or Azure Resource Manager. These services allow you to define and manage cloud infrastructure using native tools and resources specific to each cloud platform.

Containerization and container orchestration: In containerized environments, tools like Docker and Kubernetes help manage the packaging and deployment of applications and microservices. While not strictly IaC tools, they are often used in conjunction with IaC to achieve infrastructure automation in containerized environments.

Monitoring and logging: Monitoring and logging tools help keep track of the health and performance of your infrastructure. They ensure that the IaC-deployed resources are running as expected. Popular tools include Prometheus, Grafana, and the monitoring services provided by cloud providers.

Infrastructure as Code relies on a range of tools to automate infrastructure provisioning and management. These tools fit into categories like configuration management, provisioning, version control, CI/CD, cloud provider services, containerization, and monitoring. The combination of these tools allows organizations to achieve efficient, scalable, and consistent infrastructure management through code.

DevOps is a set of practices and cultural principles that emphasize collaboration and communication between development (Dev) and operations (Ops) teams. It promotes a shared responsibility for the entire software delivery lifecycle, including infrastructure management.

In a DevOps environment, IaC becomes a crucial tool, helping organizations achieve the DevOps goal of delivering software more efficiently, reliably, and with reduced manual intervention. This work is done through two key mechanisms:

• When developers make changes to application code, the IaC code is automatically executed to provision or update the underlying infrastructure.

• Because the infrastructure configuration stays consistent from development all the way into production, DevOps teams can deploy code changes with confidence that their application will work as expected.

This close integration of IaC within the DevOps workflow minimizes human error, reduces deployment complexities, and enhances overall system reliability. In essence, IaC is a technical component that aligns with the cultural and process-oriented aspects of DevOps, improving the overall efficiency and reliability of software development and infrastructure operations.

Adopting IaC involves several crucial steps to ensure a successful integration into your organization’s DevOps practices:

1. Select the right tools: Different IaC tools cater to varying needs and preferences, so it’s essential to choose the one that aligns best with your infrastructure goals and capabilities. Consider factors like your cloud provider, existing tech stack, and team’s familiarity with a particular tool.

2. Understand the tool’s syntax and methodology: Each tool has its own language for defining infrastructure configurations. For instance, Terraform uses HashiCorp Configuration Language (HCL), Ansible employs YAML, and Chef/Puppet utilize Ruby-based DSLs. Familiarizing yourself with the chosen tool’s language and principles is crucial for writing effective IaC code.

3. Begin with a pilot project: To mitigate potential challenges and reduce risks, it’s a good practice to start implementing IaC on a smaller scale as a pilot project. Select a specific infrastructure component or a subset of your overall infrastructure to apply IaC principles. This provides an opportunity to refine your IaC practices and iron out any issues before scaling up to your entire infrastructure.

By following these steps, organizations can effectively introduce IaC into their DevOps workflow, ensuring a smoother transition and reaping the benefits of improved infrastructure automation, consistency, and collaboration.

CircleCI is a powerful automation tool that can simplify the implementation of IaC for your DevOps teams.

With CircleCI, you can set up CI/CD pipelines for your IaC projects, ensuring that any changes to your infrastructure code are thoroughly tested and reliably deployed across different environments. CircleCI’s user-friendly interface and configuration options make it accessible for both developers and operations teams, helping your organization adopt IaC practices more efficiently and with less manual intervention.

To eliminate tedious, error-prone processes from your software delivery, start by adopting automation and IaC. Sign up for a CircleCI account and get up to 6,000 free monthly build minutes, or contact us for a personalized demo to see how IaC and CI/CD can help you deliver better, more reliable software with less manual effort.