GitOps represents a modern approach to automating, managing, and deploying applications and infrastructure. It relies on a version-controlled Git repository as the single source of truth for declarative configurations. In this article, we'll focus on implementing GitOps workflow on the CentOS operating system using the Argo CD tool. Argo CD is a declarative, Git-centric tool for deploying applications on Kubernetes.
Prerequisites
Before beginning the implementation, it's necessary to have a CentOS system prepared with a Kubernetes cluster installed and configured. Additionally, you'll need to have a Git repository created, containing configuration files for deploying applications.
Installing Argo CD
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Adding Argo CD to the Kubernetes Cluster
Firstly, add Argo CD to your Kubernetes cluster. This can be done by applying the Argo CD manifest directly from the official sources:
kubectl create namespace argocd kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml -
Accessing Argo CD UI
After successful installation, you can access the Argo CD UI via port forwarding:
kubectl port-forward svc/argocd-server -n argocd 8080:443
You can now access the Argo CD UI through a web browser at http://localhost:8080.
Configuring GitOps Workflow
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Setting up Git Repository in Argo CD
Upon logging into the Argo CD UI, add your Git repository as a source for deploying applications. This can be done in the "Settings" section under "Repositories." Here, you can add the address of your Git repository and any necessary authentication credentials if the repository is private.
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Creating Application in Argo CD
In the Argo CD UI, navigate to "New App" and fill in the necessary information about the application, including its name, paths to configuration files in the Git repository, and the target environment in the Kubernetes cluster. Argo CD supports both automatic and manual application deployments based on changes in the Git repository.
Management and Automation
Argo CD provides tools for monitoring application status, visualizing changes, and rolling back configurations. All these actions are performed declaratively and are recorded in the Git repository, increasing transparency and simplifying change auditing.
Security Considerations
When working with Argo CD and GitOps, it's important to ensure the security of the Git repository and access to it. It is recommended to use strong authentication mechanisms such as SSH keys or tokens and restrict access to the repository only to authorized users.
Implementing GitOps workflow on CentOS using Argo CD brings significant benefits in terms of automation, standardization, and increased efficiency of application deployment and management processes. This approach enables teams to quickly respond to changes, improve security policies, and maintain consistency between development and production environments.
