GitOps is a paradigm or a set of practices that empowers developers to perform tasks which typically fall under the purview of IT operations. GitOps requires code to be declarative and uses Git as a single source of truth for infrastructure automation and deployment. This article will delve into the intricacies of GitOps workflows in the context of cloud computing, providing a comprehensive understanding of its definition, explanation, history, use cases, and specific examples.
GitOps, a term coined by Weaveworks, is a way to do Continuous Delivery; it uses Git as a 'single source of truth'. The Git repository in a GitOps model is not just the source of version control for the team. It is the central hub for all infrastructure and application configuration.
Definition of GitOps
GitOps can be defined as an operational framework that takes DevOps best practices used for application development such as version control, collaboration, compliance, and CI/CD, and applies them to infrastructure automation. The 'Git' in GitOps comes from the use of Git as the single source of truth. The 'Ops' refers to the development and operations teams collaborating to ensure the stability and reliability of the system.
The GitOps model fundamentally changes the way operations are performed. Instead of manually pushing changes to the system, changes are merged into the Git repository. This allows for easy tracking of changes, quick rollbacks if necessary, and efficient collaboration between teams.
Key Components of GitOps
The two key components of GitOps are the Git repository and the Kubernetes cluster. The Git repository is the single source of truth for both the desired and actual state of the system. The Kubernetes cluster is the system that executes the desired state defined in the Git repository. It is important to note that while Kubernetes is commonly used in GitOps workflows, it is not a requirement.
The GitOps workflow can be broken down into four key principles. These principles are: declarative configuration, version controlled and approved changes, automated deployment, and software agents to ensure correctness. These principles work together to provide a robust, repeatable, and reliable system.
Explanation of GitOps
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, including Git and Continuous Deployment tools.
The core idea of GitOps is having a Git repository that always contains declarative descriptions of the infrastructure currently desired in the production environment and an automated process to make the production environment match the described state in the repository. If you want to deploy a new application or update an existing one, you only need to update the repository - the automated process handles everything else. It's like having a 'undo' button for your infrastructure, and it can make your entire system more resilient and stable.
How GitOps Works
GitOps works by using Git as a single source of truth for declarative infrastructure and applications. With Git at the center of your delivery pipelines, every pull request can be made to represent an update to the application, resulting in a new application revision. This revision is tested and deployed to a production-like environment. If everything looks good, the pull request is merged, and the new revision is deployed to production.
The deployment pipeline is triggered by Git, and it uses an image repository that is accessible to the Kubernetes cluster. The pipeline pushes the image and updates the GitOps repository. The GitOps operator notices the repository change and updates the Kubernetes cluster.
History of GitOps
The term GitOps was first coined by Alexis Richardson, CEO of Weaveworks, during a talk in 2017. The idea was to bring the best practices of software development to operations, by using Git as a version control system for all operational specifications.
The concept of GitOps was born out of the need for a more efficient and reliable way to manage complex systems. Traditional operations management often involves manual processes, which can lead to errors, slow recovery times, and a lack of visibility into system state. GitOps addresses these issues by applying the principles of Git to operations management.
Evolution of GitOps
Since its inception, GitOps has evolved to become a core part of many DevOps practices. It has been adopted by many organizations due to its ability to improve productivity, reduce errors, and make rollbacks easier. GitOps has also been integrated into many DevOps tools, making it easier for teams to adopt GitOps practices.
GitOps is now considered a best practice for cloud native application delivery. The growth of Kubernetes has also contributed to the popularity of GitOps, as GitOps principles are a natural fit for Kubernetes' declarative model of the desired state.
Use Cases of GitOps
GitOps can be used in a variety of scenarios, ranging from managing large-scale infrastructure to deploying small microservices. It is particularly useful in environments where there is a need for speed, as it can significantly reduce the time to deploy changes. It is also beneficial in organizations where there are strict compliance and audit requirements, as it provides a clear audit trail of changes.
One of the most common use cases of GitOps is in multi-tenant Kubernetes environments. In these environments, multiple teams or tenants are sharing the same Kubernetes cluster. GitOps can provide each tenant with a separate Git repository, allowing them to manage their own applications and resources independently.
Examples of GitOps
A specific example of GitOps in action is the use of a GitOps workflow to manage a multi-tenant Kubernetes cluster. Each tenant has their own Git repository and makes changes to their applications and resources by making commits to their repository. These changes are then automatically applied to the cluster by the GitOps operator.
Another example is the use of GitOps in a CI/CD pipeline. In this scenario, a developer makes a change to the application code and commits the change to the Git repository. This triggers the CI/CD pipeline, which builds a new image of the application, pushes it to the image repository, and updates the GitOps repository. The GitOps operator then notices the change to the repository and deploys the new image to the Kubernetes cluster.
Conclusion
GitOps is a powerful tool for managing complex systems. By using Git as a single source of truth, it brings the benefits of version control to operations, making the system more reliable, resilient, and easier to manage. Whether you're managing a large-scale infrastructure or deploying a small microservice, GitOps can make your operations more efficient and effective.
As we continue to move towards a world where everything is code, the principles of GitOps will become increasingly important. By adopting GitOps practices, teams can improve their productivity, reduce errors, and make their systems more resilient. So, if you're looking to improve your operations, it might be time to consider GitOps.