Work Smarter, Not Harder: Transform IT with Configuration as Code

Henry Ford showed the world the scalable advantage of assembly lines. Building a single car in your garage is certainly feasible, especially for a one-of-a-kind vehicle. However, this approach is impractical for mass production. Ford's assembly line revolutionized manufacturing by enabling cars to be produced efficiently and at scale, making them accessible to the masses.  

Configuration as Code (CaC) is the equivalent of introducing an assembly line to deploy and manage your system configurations across your enterprise. A CaC approach transforms traditional configuration deployments into repeatable, automated, and scalable events. Rather than manually configuring each system, you can define the process once and replicate it efficiently across your multitude of environments, whether managing tens, hundreds, or thousands of systems. 

Watch: Introduction to CaC with Daniel Perrinez

A Close Look at CaC 

The founding principle of CaC is that configuration data is now treated as versioned artifacts. This allows for better tracking and iteration of changes. System configurations are defined in files and stored in source code repositories to ensure they are structured and version controlled. See our previous introductory blog on Git to learn more.  

CaC leverages these managed system settings to automate deployments across various environments to maintain consistency and reduce errors. It can be applied to a wide range of systems, including firewalls, switches, servers, and cloud infrastructure. 

While Git serves as the collaborative repository for tracking changes, CaC automation tools such as YAML, Ansible, and PowerShell are used to define and deploy configurations. These tools allow teams to manage infrastructure declaratively for readability and sharing. 

To better understand what CaC is fully capable of, let’s consider a real-life example of CaC.  

Scenario #1: Configuring VLANs 

Let’s take something as simple as creating or consolidating VLANs on switches. It is an easy task for an experienced network admin. You can create a VLAN within a minute on a designated switch. Let’s say you wanted to consolidate two VLANs into one - add another minute. But now let’s scale this task out to an entire fleet of 500 switches across different environments. Sure, you could copy and paste the code but now you introduce some challenges: 

• Human Error: Copy-pasting CLI commands risks typos or misconfigurations (e.g., incorrect VLAN IDs or trunk ports). 

• Lack of Visibility: No centralized tracking of changes or failures across devices. 

This traditional CLI approach hits its limitation quickly as the number of switches increases. However, using a configuration as code approach now transforms the process into a scalable, auditable workflow using a one-two punch: 

Version Control with Git: 

Store VLAN configurations in a Git repository (e.g., vlans.yaml), to enable: 

• Change Tracking: Compare revisions to see when VLAN 30 and 40 were merged into VLAN 50. 

• Collaboration: Teams review changes via pull requests, catching errors before deployment. 

• Rollbacks: Revert to a known-good state if issues arise. 

Automated Deployment with Ansible: 

• By defining configurations in YAML files, Ansible ensures that the settings are consistently applied across all switches and ensures configurations are applied only if needed 

• Use Ansible playbooks to deploy VLAN configurations with real-time feedback to show the success or failure of the deployment along with error details. 

Configuration as Code does more than just save you time in this case. It reduces risk, improves collaboration, and transforms network operations from reactive to reliable and repeatable. 

Watch: What Is HPE Private Cloud AI?

Advantages of CaC 

The above scenario clearly demonstrated some of the key advantages of a configuration as code approach for large enterprises: 

• CaC allows system settings to be managed and versioned in a source code repository like Git where configuration changes can be tracked and reverted if necessary  

• Defining system settings in files and automating their application ensures that configurations are consistent across different environments  

• CaC enables the reproducibility of configurations which makes it easy to replicate environments for testing, development, and production  

• CaC reduces manual errors by automating the process of configuring systems using tools like Ansible  
• The agentless architecture of Ansible makes it highly scalable and efficient in managing configurations across large environments, whether it's tens, hundreds, or thousands of nodes.
  

Scenario #2: Creating VMs in AWS 

Creating several VMs in AWS is a relatively simple task. It is part of the beauty of using a cloud portal. Creating three VMs can be completed within a dozen clicks or so. This includes things such as selecting options like OS, instance type, key pairs, storage, and a few tags. While this process is manageable for small-scale tasks, it becomes inefficient and error prone when scaled to hundreds of VMs or multiple environments such as dev, test and production. Relying on the manual creation of VMs using a GUI interface increases the likelihood of inconsistencies and forgotten configurations.  

Automated Method Using Terraform ‘Infrastructure as Code’ (IaC): 

“Infrastructure as Code” is a subset of “Configuration as Code” and largely achieves the same goals. Terraform IaC allows defining cloud resources, like VM configurations, in a single code file. Key attributes like instance count, types, and tags are stored in version-controlled files (e.g., Git). Tags defined in the Terraform configuration are used for tracking and categorizing cloud resources.  

The advantages of this approach are: 

• Ensures all configurations are consistent across environments 

• Easily deploys hundreds of VMs without additional effort 

• Eliminates repetitive manual input, and facilitates collaboration by enabling teams to review and track changes over time 

• Tags and configurations are stored in code, ensuring standardization and reducing human error 

CaC Best Practices 

Here is a list of CaC best practices to ensure you are getting the most out of your projects: 

• Those just getting into CaC should use an integrated development environment (IDE). A great choice is Visual Studio Code. It’s widely supported and it is free. 
• Auto-check your code using tools like linters. 

• Use Git to encourage greater developer collaboration and code review. Git ensures that configuration changes are tracked and can be reverted if necessary 

• Don’t start from scratch. Both Terraform and Ansible offer published templates to get you started. You can also go to Github or Gitlab and search for the code you need because chances are it is mostly written already by someone else in the community.  

Configuration as Code is fundamentally about working smarter, not harder. By minimizing the risk of human error, streamlining scalability, and offering a transparent audit trail for changes, CaC enhances efficiency and consistency across IT operations. CaC can help transform how your IT teams operate to ensure a future-ready IT ecosystem that can easily evolve and scale with your business. Let's get started with your enterprise.