The concept of GitOps was first launched by WeaveWorks, a management firm of Kubernetes, and has extended to the whole DevOps community ever since. GitOps is an IaC extension and declaratory configuration.
“GitHub is a code-based infrastructure. Its operational procedures rely on Git’s resource control system. What that means is – we are maintaining the system but in a declarative way. We are keeping all the changes in the version control. Using a Git as a source control system, we are maintaining our infrastructure and operational system.” – Sivamuthu Kumar, Senior Software Architect in Computer Enterprises Inc. and an AWS Community Builder, at a webinar with Whizlabs on GitOps: Continuous and Progressive Deployment in AWS EKS.
What Is GitOps?
Launched in 2017, GitOps is an operational model. It provides a range of best practices to combine Git deployment, monitoring, and management in containerized Cluster applications for Kubernetes and other cloud-native technologies.
It is a means of managing and delivering applications in clusters in Kubernetes and other cloud-based technologies.
With GitOps, software agents can create an alert if a difference is found between Git and what is going on in a cluster. When there is a difference, Kubernetes reconcilers update or roll back the cluster automatically, suitable to the case. With Git at the heart of your delivery pipelines, developers use familiar tools to speed up and streamline applications and operating chores for Kubernetes.
For the automation of infrastructure, GitOps requires familiar tools like Git and continuous supply pipelines. The GitOps strategy is neutral to the supplier, providing a clear history of changes and permitting reproduction or reverse deployments.
To start cluster management of applications and systems with GitOps, these principles should be set in place.
Declarative configuration of the entire system
“Declarative” indicates that a set of facts, rather than a set of instructions, guarantees the configuration. When applications are set as declarative, they have a sole source of truth in Git. Then, you can simply deploy and roll back these applications from and to Kubernetes. More crucially, the infrastructure of your cluster can be duplicated reliably and rapidly when a mishap hits.
The desired standard system state
You have a single point from which everything is derived and driven by the statement of your system in a version control system that serves as your canonical source for truth. This banalizes rollbacks, where a ‘Git revert’ can be used to return to the former application status.
Approved changes that can be automatically applied to the system
The next step is to allow any changes to this state to be applied to your system automatically when you have the described state in Git. And to change your system, you do not require cluster credentials. The state definition lives outside of an isolated environment with GitOps. You can therefore distinguish what you do and how you do it.
Software agents ensure accuracy and divergence alert
Once the system status has been defined and controlled, software agents can warn you whenever your expectations and reality diverge. The employment of agents ensures the complete self-healing of your system. In this instance, the feedback and control loop for your processes is provided by software agents.
Benefits of GitOps
With its powerful technology and management, GitOps features several benefits.
Continuous deployment automation with a built-in feedback controller accelerates the time to deployment. Your team can make 30-100 times more changes each day, enhancing the development performance 2-3 times over.
Improved experience for developers
Developers may use common tools such as Git to handle Kubernetes upgrades and features more quickly without knowing Kubernetes internally. This allows the new developers to speed up and be productive in days rather than months.
You will automatically acquire a simple audit trail of any cluster modifications outside of Kubernetes, by using Git workflows to manage your cluster. An audit log of who did what and when can be utilized to ensure compliance with SOC 2. This means higher stability in your cluster.
You get stable and reproducible roll-back using Git’s ability to reverse/roll and fork. Since Git describes all your systems, your source of truth can be recovered from a meltdown, which means that your system is reduced from hours to minutes to recovery (MTTR).
Push & Pull Workflow
GitOps deployment technique can be implemented in two ways: Push-based and Pull-based deployments. The distinction between the two types is how the deployment environment is verified and is genuinely similar to the desired infrastructure. The Pull-based strategy, being recognized as the safer and better practical way of implementing GitOps, should be preferred where possible.
Push Based Workflow
The popular CI-CD solutions, such as Jenkins, CircleCI, or Travis, implement the Push-based deployment technique.
Whenever the application code is updated, it is activated by a build pipeline that produces container images, and finally updates the environment configuration repository to new deployment descriptors.
With this strategy, credentials for the deployment environment are indispensable. The pipeline is thus activated in god-mode. In some circumstances, when an automated cloud infrastructure supply is run, a Push-based deployment is inevitable. In these cases, it is advised for more stringent deployment rights to use the cloud provider’s fine granular adjustable authorization mechanism.
Pull Based Workflow
The Pull implementation technique uses the same concepts as the push-based alternative, but the workings of the pipeline are different.
For example, an external case is generated by traditional CI/CD pipelines, when new code is pointed to an application repository.
The operator is initiated using pull-based deployment. It takes over the job of the pipeline by continuously comparing the expected state with the current status of the deployed infrastructure in the environment repository. The operator upgrades the infrastructure to match the environment repository if deviations are noticed. The image registry can be monitored to find new versions of images to deploy.
To see the working process of Push and Pull workflow, along with a detailed explanation of GitOps and its procedure, you can watch our intensive webinar. Here, our featured speaker and expert, Sivamuthu Kumar, has thoroughly covered GitOps, its process, challenges, GitOps versus DevOps, GitOps Operators, and EKS.
To learn about the above topics in detail and more, you can watch our recorded webinar here:
- Cloud Armor – A Complete Guide - September 28, 2021
- GitOps: Continuous and Progressive Deployment in AWS EKS – Sivamuthu Kumar - September 27, 2021
- What is Cloud AutoML? - September 24, 2021
- What is Cloud NAT? - September 23, 2021
- A Guide to GKE Clusters (Google Kubernetes Engine) - September 22, 2021