Introducing GitOps

GitOps, a trending approach for managing infrastructure as code (IaC), has gained significant popularity in recent times. In this article, we will provide you with a comprehensive introduction to GitOps, highlighting its advantages and disadvantages. Additionally, we will explore a selection of GitOps tools that can assist you in initiating your GitOps journey.

Let’s dive into this topic and discover how GitOps can revolutionize your infrastructure management practices.

This post is part of “Azure Arc Series - Manage an on-premises Kubernetes Cluster with Azure Arc”.

What is GitOps?

GitOps is an approach that leverages the concept of infrastructure as code (IaC) to streamline the management of complex configurations. While traditional IaC tools like Terraform and Ansible focus on deploying infrastructure, GitOps takes it a step further by utilizing a separate Git repository to store all configuration files.

By centralizing configurations in a Git repository, developers can establish a single source of truth for their infrastructure. This enables version control and facilitates the implementation of robust deployment pipelines. With GitOps, you can ensure that you always have visibility into which version of the configuration is running in a specific environment.

One of the key advantages of GitOps is its ability to promote repeatable and scalable deployments. By treating infrastructure changes as code, you can achieve fast and reliable deployments through automation. This not only enhances efficiency but also fosters collaboration among teams by providing a standardized and easily understandable representation of the infrastructure.

Another benefit of GitOps is improved security. With GitOps, developers no longer require direct access to the underlying infrastructure. Instead, changes are implemented through controlled pipelines, reducing the risk of unauthorized modifications and enhancing overall security posture.

As Kubernetes and cloud environments continue to gain prominence, GitOps becomes even more relevant. It extends the concept of IaC to cover additional aspects such as network configurations, security policies, and application configurations. This comprehensive approach allows developers to manage all aspects of their infrastructure and configurations as code, simplifying complex deployments and ensuring consistency across environments.

In the following sections, we will explore both the advantages and potential challenges of adopting GitOps. We will also introduce you to some popular GitOps tools that can help you kickstart your GitOps journey.

Deployment Modes

Pull-based deployments: In this mode, a vigilant agent or operator operates within your environment’s confines. Its duty is to diligently monitor a preconfigured Git repository and the specified branch for any updates. Once changes are detected, the agent adeptly pulls these alterations and sets them into motion, executing the necessary actions. A notable advantage of this approach lies in its ability to fortify your environment by blocking all incoming traffic, while permitting outbound traffic solely on port 443.

Push-based deployments: As the name suggests, this mode involves pushing your changes directly into the configured environment. For most developers, this method is the default way of deploying changes, akin to the workings of a continuous delivery (CD) pipeline.

Azure Arc uses the pull-based approach and I will talk about this approach in more detail in a later post of this series.

Benefits of GitOps

Embracing GitOps as your deployment process unlocks a wide range of benefits, including:

Version Control Integration: By checking Infrastructure as Code (IaC) files into your version control system, GitOps establishes a solid foundation for traceability, collaboration, and seamless management of your configuration changes.
Automated Testing: The power of automation shines through as GitOps empowers you to conduct automated tests on your configuration files. This validation process, such as verifying the integrity of YAML files, ensures a higher degree of accuracy and reduces the likelihood of configuration errors.
Enhanced Quality through Pull Requests: The implementation of pull requests for configuration changes serves as a guardian, bolstering the quality and coherence of your configuration files. This practice fosters a collaborative environment, enabling knowledge sharing and collective scrutiny before integrating changes into the system.
Streamlined Continuous Deployment Pipelines: GitOps seamlessly integrates with Continuous Delivery (CD) pipelines, bestowing you with complete visibility over the deployed configuration versions in your environment. This facilitates smooth rollbacks in case of contingencies, granting you the confidence to navigate challenges with ease.
The Single Source of Truth: With the Git repository serving as the single source of truth for your infrastructure and configuration, ambiguity is eradicated. This cohesive approach ensures consistency across teams and environments, promoting a harmonious development landscape.
Heightened Security: Security takes center stage as GitOps mitigates risks by confining access to your environment solely to the CD pipeline. This reduction in direct access to the underlying infrastructure bolsters your security posture, fortifying against unauthorized modifications and potential threats.

Disadvantages of GitOps

As with any tool or feature, GitOps also comes with a set of considerations to bear in mind, including the following disadvantages:

Increased Management of Git Repositories: Adopting GitOps often entails managing multiple Git repositories, each serving as a source of truth for different aspects of your infrastructure. This proliferation of repositories may introduce complexity and overhead in terms of organization and maintenance.
Reduced Flexibility with Pull-Based Approach: The pull-based deployment approach, while secure and automated, may limit some flexibility compared to traditional CD pipelines. For instance, when using GitOps, configuration files need to be predefined for each environment, making on-the-fly changes to variables during deployment less feasible.
Challenges in Secret Management: One notable challenge in GitOps is handling sensitive information such as secrets and passwords. As Git repositories should ideally be public, storing sensitive data directly within the repository is not advisable. Instead, external solutions like Azure Key Vault or other secure secret management tools must be employed to safeguard these crucial credentials.

GitOps Tools

There is a wide variety of tools available if you want to use the push deployment model for your configuration:

Terraform : A widely acclaimed infrastructure provisioning tool, Terraform empowers you to codify your infrastructure and efficiently manage resources across various cloud providers.
Pulumi : Pulumi is a versatile platform that enables infrastructure as code using familiar programming languages, making it accessible to developers who prefer a more programmatic approach.
Ansible : Renowned for its simplicity and flexibility, Ansible automates application deployment, configuration management, and other IT tasks, making it an indispensable tool for GitOps practitioners.
Chef : An automation platform, Chef facilitates configuration management and application deployment through reusable code known as cookbooks, ensuring consistency across diverse environments.
Azure CLI : As the official command-line interface for Microsoft Azure, Azure CLI provides a comprehensive set of commands to manage Azure resources programmatically.

There are two popular tools for the Pull Deployment Model:

Flux (Flux is used in Azure Arc and will be used to deploy applications in a later post): Leveraged by Azure Arc and adept at deploying applications, Flux boasts a powerful pull-based approach, allowing continuous delivery of configurations and applications with ease.
ArgoCD : Known for its declarative and GitOps-centric nature, ArgoCD automates the deployment of Kubernetes applications, streamlining the management of complex applications in Kubernetes clusters.

While the push deployment model enjoys a wealth of well-established tools, the pull model, being relatively newer, has a more limited but promising selection.

Conclusion

In conclusion, GitOps emerges as a transformative approach, seamlessly blending the principles of DevOps with configuration management. By encapsulating configuration files within code repositories, such as YAML files, GitOps empowers developers to manage infrastructure changes with the same agility and rigor as application code. This harmonious integration fosters transparency, consistency, and collaboration, elevating the quality and reliability of the entire system.

The security paradigm is enhanced as developers no longer require direct access to the underlying infrastructure. GitOps’ controlled and automated deployment process curtails unauthorized modifications, fortifying the ecosystem against potential risks.