What is GitOps? A step-by-step guide

GitOps is a way of implementing Continuous Deployment for cloud native applications. It focuses on a developer-centric experience when operating infrastructure, by using tools developers are already familiar with, primarily Git. 

The core idea of GitOps is having a Git repository that contains the declarative descriptions of the infrastructure you need in your production environment, and an automated process to make the production environment match the desired state in the repository.

This method allows for a version-controlled system that enables developers to easily track changes, roll back if necessary, and work in a controlled environment. It also makes it possible for the whole team to see what’s happening in the system at any given time.

Foundations of GitOps 

The following are basic principles of GitOps that will help you understand its novel approach.

Git, Kubernetes, and Continuous Deployment

To understand GitOps, it’s crucial to understand the key technologies it is typically used with: Git, Kubernetes, and Continuous Deployment. Git is a version control system that tracks changes to a set of files over time. It allows multiple people to work on the same project without overwriting each other’s changes. Kubernetes is an open-source container orchestration system for automating the deployment, management, and scaling of containerized applications. Finally, Continuous Deployment is a software development practice that involves code changes that are automatically prepared for a release to the production environment.

In GitOps, these three concepts intersect to create a robust, developer-friendly system for managing complex applications. Git serves as the single source of truth for the system’s current desired state, while Kubernetes automates the process of deploying the desired state to the actual environment. Continuous Deployment practices ensure that changes to the system are  applied automatically and consistently, minimizing the risk of human error.

Git Becomes the Single Source of Truth

In GitOps, Git is not just a version control system; it becomes a single source of truth for the entire system. This means that the desired state of the system is stored in a Git repository, and all changes to that state are made through Git. This is a departure from traditional operations, where changes might be made directly in the live environment.

This approach has several benefits. First, it ensures that the entire history of the system is stored in an easily accessible place. If something goes wrong, developers can easily trace back through the Git history to find out what changed and when. Second, it ensures that all changes are reviewed and approved before they are applied. This adds an extra level of security and reliability to the system.

Immutable Infrastructure and Declarative Systems

Another core principle of GitOps is the concept of immutable infrastructure and declarative systems. In an immutable infrastructure, once a component is deployed, it never changes. Instead, any changes are made by deploying a new version of the component. This reduces the risk of configuration drift and makes the system more reliable.

Similarly, GitOps depends on declarative systems, where the target state of the system is described, and the system automatically adjusts to match that state. This is in contrast to imperative systems, where specific commands are issued to change the system’s state. Declarative systems are easier to manage, as they require less manual intervention and are less prone to errors.

Benefits of Adopting GitOps for Cloud Native Development 

Faster Deployments and Improved Consistency

One of the most significant benefits of adopting GitOps for cloud native development is enhanced deployment speed and consistency. With GitOps, developers can push code to production faster and with a higher degree of confidence. This is because the deployment process is automated and standardized, reducing the risk of human error.

Additionally, because all changes are tracked in Git, it’s easy to roll back to a previous state if something goes wrong. This means that developers can experiment and innovate more, knowing that they have a safety net if they make a mistake.

Traceability and Auditing

Another key benefit of GitOps is the enhanced traceability and auditing it provides. Because every change is tracked in Git, it’s easy to see who made a change, when they made it, and what exactly they changed. This makes it easier to diagnose issues and to hold individuals accountable for their changes.

Moreover, this traceability is particularly valuable in regulated industries, where companies need to prove that they have control over their systems. With GitOps, it’s easy to provide compliance auditors with a complete history of changes to the system, making it simpler to comply with regulatory requirements.

Simplified Rollback and Versioning

One of the most significant advantages of GitOps is the way it simplifies rollback and versioning. With traditional methods, rolling back to a previous version of an application or infrastructure due to a failure or error can be a complex and time-consuming process.

With GitOps, your entire system state is version-controlled in Git. This means that you can easily roll back to a previous state, in the same way you might revert to a previous commit in your code. All changes are tracked, providing a clear audit trail describing who did what and when. This makes troubleshooting easier and increases the reliability of your systems.

Reduced Human Error

Another key benefit of GitOps is its ability to reduce human error through automation. In traditional workflows, developers or operators might manually apply changes to the infrastructure, which can lead to inconsistencies and errors.

GitOps, on the other hand, uses a declarative approach to automation. You declare the desired state of your system in your Git repository, and automated processes ensure that your actual system matches this desired state. This eliminates the need for manual intervention and decreases the risk of human error.

Moreover, with GitOps, all changes go through a version control system. This means that you have peer review and automated testing before any change is applied to your system. This further reduces the risk of errors and ensures high-quality output.

Best Practices for GitOps with Cloud Native Apps 

Organizing Repositories: Mono-Repo vs. Multi-Repo Strategies

When implementing GitOps, one of the first decisions you’ll need to make is whether to use a mono-repo or multi-repo strategy for organizing your repositories. Each approach has its pros and cons, and the choice largely depends on your specific needs and context.

A mono-repo strategy involves storing all your code in a single repository. This can simplify dependency management and make it easier to coordinate changes across different parts of your system. However, a mono-repo can become difficult to manage as your system grows.

On the other hand, a multi-repo strategy involves having separate repositories for different parts of your system. This can make it easier to manage large systems and can provide better isolation between different components. However, it can also make dependency management and coordination more complex.

Handling Configuration and Secrets

Handling configuration and secrets is another critical aspect of GitOps. Configuration should be stored in your Git repository along with your code. This ensures that your configuration is version-controlled and that it goes through the same peer review and automated testing processes as your code.

Secrets, on the other hand, should not be stored in your Git repository due to security risks. Instead, they should be managed using a secure secret management solution that integrates with your GitOps workflow. This ensures that your secrets are securely stored and are only accessible to those who need them.

Ensuring High Availability and Zero-Downtime Deployments

High availability and zero-downtime deployments are crucial for maintaining a quality user experience. GitOps can facilitate these through its declarative approach and automated processes.

In GitOps, you declare the desired state of your system, including the number of instances of your application that should be running. Automated processes ensure that this desired state is maintained, automatically replacing any failed instances. This ensures high availability of your application.

Zero-downtime deployments can be achieved through strategies such as rolling updates, canary releases, and blue-green deployments. These strategies involve gradually rolling out changes and ensuring that there is always a version of your application available to serve user requests. These strategies can be easily implemented as part of your GitOps workflow.

Incorporating Database Migrations and Stateful Components in GitOps

Database migrations and stateful components can be challenging to manage in a GitOps workflow. However, with careful planning and the right tools, these challenges can be overcome.

Database migrations should be version-controlled in your Git repository and treated as part of your application’s code. They should be tested and reviewed before being applied to your system.

Stateful components, such as databases and message queues, require persistent storage and careful management to maintain their state. Operators, which extend Kubernetes to automate the deployment and management of stateful components, can be used in a GitOps workflow to manage these components effectively.

Conclusion

GitOps represents a major shift in the way we manage and operate our systems. By applying the principles and practices of GitOps, we can increase the reliability, efficiency, and quality of our software development and operations. However, like any approach, GitOps requires careful planning and implementation to be successful. By following the best practices discussed in this guide, you can start your GitOps journey on the right foot.