CI/CD Pipeline with ArgoCD, Jenkins, and Helm for Kubernetes: A Step-by-Step Guide

The provided diagram illustrates a CI/CD pipeline architecture for a Kubernetes-based environment, integrating containerized applications with CI tools, CD tools (ArgoCD), Helm, and Kubernetes clusters. Below is a step-by-step breakdown:

1. Developer Workflow

• Commits Code:
  • A developer writes and commits application code to a source code repository (e.g., GitHub, GitLab, or Bitbucket).
• Changes Config:
  • The developer also modifies Kubernetes configuration files, such as Helm charts or Kubernetes manifests, which are stored in a version-controlled repository.

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2. CI Pipeline (Continuous Integration)

• Code Build and Image Creation:
  • A CI pipeline is triggered when new code is committed to the repository. This pipeline includes:
    1. Building the Code: Tools like Jenkins, CircleCI, or GitLab CI are used to compile and test the code.
    2. Creating a Container Image: Once the code passes the tests, a container image is built using tools like Docker.
  • Push Image to Repository:
    • The newly created container image is pushed to an image repository (e.g., DockerHub, Amazon Elastic Container Registry, or another container registry).
    • This image becomes the deployable artifact for the application.

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3. CD Pipeline (Continuous Deployment)

• Configuration Management:
  • Any changes made to the Kubernetes configuration (e.g., Helm charts or Kubernetes manifests) are committed to a configuration repository.
  • The CD pipeline monitors this repository for changes.
• ArgoCD Sync:
  • ArgoCD, a declarative GitOps tool, continuously syncs the changes from the configuration repository.
  • ArgoCD ensures the Kubernetes clusters are always aligned with the desired state defined in the configuration repository.
  • It uses Helm charts or raw Kubernetes manifests to define the application’s desired state and infrastructure configuration.

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4. Deployment to Kubernetes Clusters

• Multiple Environments:
  • The architecture supports multiple Kubernetes environments:
    • Dev: Used for development and integration testing.
    • Test: Used for staging and performance testing.
    • Prod: The production environment for live traffic.
  • Each environment is managed via the same GitOps process with ArgoCD ensuring consistent deployments across Dev, Test, and Prod environments.

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Key Components

1. CI Tools:
   • Jenkins, CircleCI, or similar CI tools are used for code testing, building, and image creation.
2. Image Repository:
   • Container images are stored in a repository like DockerHub, AWS ECR, or GCR.
3. CD Tools:
   • ArgoCD automates the deployment process and ensures Kubernetes clusters are always synchronized with the Git repository.
4. Helm:
   • Helm is used as a package manager for Kubernetes, allowing efficient deployment and management of Kubernetes applications.
5. Kubernetes Clusters:
   • Separate Kubernetes clusters for Dev, Test, and Prod environments provide environment isolation and scalability.