Need for Automation - GitOps at Scale

Building a skyscraper is a lot like building software. Initially, you might experiment with materials on a different site or check how beams handle stress. Once confident, you lay the foundation and then start building upwards. Similarly, in software development, you kick things off with a proof of concept (POC) on a small scale. Once you're convinced of the tooling's capacity, you scale up to production. GitOps is no different.

Beginning typically with trials and using Git as the backbone for declarative infrastructure and applications, the challenge arises as you scale: how do you efficiently manage everything? And just as you'd need machinery to help construct a skyscraper, in the world of GitOps, tools like Terraform become invaluable, especially when setting up or "bootstrapping" these automation tools. In this blog, we'll navigate through the early, middle, and advanced stages (day 0, day 1, and day 2) of GitOps and explore how Terraform can simplify the scaling process for day 2.

Day 0 GitOps Challenges: Laying the Groundwork

Day 0 in GitOps can be likened to the preparatory phase of constructing a skyscraper where materials and designs are rigorously tested. At this initial stage, you're not delving into the complexities of scaling. Instead, you're laying the groundwork, familiarizing yourself with the fundamental principles of GitOps.

A practical starting point is to set up a basic GitOps workflow to deploy a Kubernetes manifest from a single git repository to a single cluster. At this juncture, the majority of tasks can be managed directly through the CLI or UI. The environment is simple enough that manually invoking commands or using native interfaces is sufficient. While tools like Terraform offer automation benefits, they're not essential at this stage. The primary objective of Day 0 is exploration: understanding the tools, assessing their fit, and choosing the best ones for your specific needs. The experience and knowledge garnered here form the bedrock for the challenges and complexities of the stages ahead.

Day 1 GitOps Challenges: Setting the Foundation

Day 1 in GitOps is like getting the ground ready for building a skyscraper. After your first dive into GitOps, the real work begins.

A big task is figuring out how to keep application code and configuration separate. When your app has services across multiple Git repositories, how do you make sure everything deploys smoothly and works together?

Next, as you start automating your CI pipeline, there's a tricky part: if you push manifest changes to a Git repository, you might accidentally start an endless cycle of build jobs and commits. You need to set up your pipelines right to avoid this mess.

Also, as you add more to your app, developers will need to deploy different services, like deployments and stateful sets. Each of these might have its own settings. While tools like Kustomize can help, if you're not careful, you can end up with "overlay folders hell". It becomes hard to know what's where and manage everything.

Day 1 is all about sorting out these early challenges, setting things up so you're ready for bigger tasks and scaling in the next stages.

Day 2 GitOps Challenges: Automation Complexities

As we progress to Day 2 of our GitOps journey, we encounter several challenges:

1. Bootstrapping: Tools like ArgoCD are great for automating deployments, but how do we set up ArgoCD itself? This is the classic bootstrapping problem in the GitOps context.

2. Tool Reliability: Automation is essential for system consistency. But this is true ONLY if the automation tool is reliable and consistent.

3. Understanding the End Goal: With declarative tools like Kubernetes and Terraform, we define the desired outcome. However, we need to clearly understand and define that end state first.

Terraform offers solutions to these Day 2 challenges:

Tackling the Bootstrapping Dilemma: One of Terraform's core strengths is its ability to set up and provision tools. So, when it comes to initializing GitOps tools like ArgoCD, Terraform can declaratively define the infrastructure, software installations, and configurations. This helps sidestep the "chicken or the egg" problem because Terraform is the tool you use to deploy your deployment tools.

Ensuring Reliability and Consistency: Terraform is designed with idempotency in mind, meaning you can run the same configuration multiple times and get the same result. This ensures that your infrastructure is reliable and consistent. If something drifts from the desired configuration, Terraform will recognize it and can revert it back, ensuring that the tool itself becomes a reliable part of the automation process.

Setting Clear End Goals with a Declarative Approach: With Terraform, you define your infrastructure as code in a declarative manner. You specify what you want the end state to look like, and Terraform figures out how to achieve it. This directly answers the challenge of needing to know your end state: you define it in your Terraform configuration, and the tool takes care of making it happen.

For a closer look at how Terraform can boost GitOps automation, this webinar provides more insights:

Build software like skyscrapers

Just as constructing a skyscraper involves meticulous planning, testing, and execution in phases, the journey of GitOps follows a similar trajectory. We start with small-scale experiments, lay a robust foundation, and then scale up, tackling complex automation challenges along the way. Each stage has its hurdles, but as we've seen, with the right tools and strategies, these challenges can be addressed effectively. Terraform, in particular, stands out as a battle-tested tool in this journey, providing solutions to many of the complexities of Day 2.

If you're keen on elevating your GitOps game, especially in terms of automation, I strongly recommend giving the Harness Terraform provider a spin. Let's build software like skyscrapers - strong, scalable, and awe-inspiring!