Implement GitOps Workflow with Argo CD

[SelahattinSert]

We currently manage our Kubernetes manifests by storing them in our Git repository under the k8s/ directory. However,
deployments are likely triggered manually or via CI scripts using kubectl apply.

To improve this, we will adopt a GitOps workflow using Argo CD, making Git the single source of truth for our
application's desired state.

Goal

• Automate the deployment process by making Git the single source of truth.
• Ensure that any change merged to the main branch is automatically and safely reflected in the Kubernetes cluster.
• Increase security by removing the need for direct kubectl access for deployments.
• Provide a clear audit trail and an easy rollback mechanism through Git history.

Task Overview

• Create a dedicated namespace for Argo CD (e.g., argocd).
• Install Argo CD into the cluster using the official manifests or Helm chart.
• Configure repository access so Argo CD can read from our Git repository.
• Implement the "App of Apps" pattern:
  • Create a new directory (k8s/argo-cd/) to hold the Argo CD Application manifests.
  • Define "child" Application resources for our existing components (app, logging, monitoring).
  • Create a "root" Application that manages all other applications.
• Bootstrap Argo CD by manually applying the "root" application manifest once.
• Verify the synchronization by making a test change in a manifest (e.g., update an image tag or replica count)
  and observing that Argo CD automatically applies it.
• Update CI/CD pipelines to remove the old kubectl apply deployment steps. The pipeline's role will be to
  build and push the container image.
• Update project documentation (README.md) to reflect the new GitOps deployment workflow.

Requirements

• The state of the Kubernetes cluster must match the configuration defined in the k8s/ directory of the Git
  repository.
• The camera-onboarding application, along with logging and monitoring stacks, must be managed by Argo CD and
  report a Synced and Healthy status.
• Manual deployments via kubectl apply should be deprecated as the standard workflow.

Notes

• The initial setup should be performed on a test/staging cluster, not directly in production.
• The "App of Apps" pattern is recommended to manage multiple components declaratively.
• Argo CD's UI can be exposed via kubectl port-forward for initial setup and verification.
• Remember to secure Argo CD by changing the default admin password after installation.

Deliverables

• Argo CD is deployed and configured in the cluster.
• All applications (app, logging, monitoring) are managed by Argo CD.
• A change pushed to the k8s/ directory in the main branch results in an automatic update on the cluster.
• Updated documentation outlining the new deployment process.

[SelahattinSert]

How is this issue looking? @ozgen

[ozgen]

How is this issue looking? @ozgen

it seems to be good @SelahattinSert