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What is ArgoCD?

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Balraj Singh
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2 min read

ArgoCD is an open-source, declarative GitOps continuous delivery tool for Kubernetes, helping developers and DevOps teams automate the deployment and management of applications on Kubernetes clusters.

Key Features of ArgoCD:

  • GitOps workflow: Monitors Git repositories for changes and synchronizes them with the Kubernetes cluster.

  • Declarative application definitions and configurations: Uses Kubernetes manifests, Helm charts, or customized overlays to define application states.

  • Automated deployment and synchronization: Continuously monitors and syncs the cluster with the desired state from the Git repository.

  • Rollback and rollout capabilities: Supports rollbacks to previous states and progressive deployments like canary and blue-green deployments.

  • Application configuration management: Manages configuration using ConfigMaps, secrets, and other Kubernetes resources.

Additional Key Features:

  • Multi-environment support and multi-cluster management: Simplifies managing applications across multiple clusters.

  • RBAC and security: Integrates with Kubernetes RBAC for fine-grained access control and security.

  • Customization and extensibility: Highly customizable with support for custom plugins and hooks.

  • User-friendly web UI: Provides a web-based dashboard for monitoring deployment status and history.

  • Integration with Git providers: Supports GitHub, GitLab, Bitbucket, and other Git hosting services.

GitOps with ArgoCD: ArgoCD follows GitOps principles by defining the desired state of applications in a Git repository and continuously synchronizing the actual state with the desired state to ensure consistency.

  • Three Main Components: Argo CD architecture consists of three main components: the API server, repository server, and application controller.

  • API Server: The API server, which acts as a REST server, exposes APIs consumed by the web UI and CLI for application management (create, update, delete), application operations (sync, rollback), repository and cluster management, and authentication.

  • Repository Server: This internal service is responsible for cloning remote Git repositories and generating the necessary Kubernetes manifests. It maintains a local cache of the Git repository holding the application manifests.

  • Application Controller: A Kubernetes controller that continuously monitors running applications, comparing the current live state against the desired target state. It deploys application manifests to the destination cluster, detects out-of-sync states, takes corrective actions, and invokes user-defined hooks for lifecycle events.

  • Continuous Synchronization: The architecture ensures continuous synchronization of the actual state with the desired state defined in Git, handling the entire continuous delivery workflow through its core components.

ArgoCD