GitOps – Core Principles

 

GitOps – Core Principles (Important Points)

• Git as Single Source of Truth

  • All infrastructure and application definitions live in Git

  • Git reflects the desired state

• Declarative Configuration

  • Define what the system should look like, not how to do it

  • Typically Kubernetes YAML, Helm, Kustomize

• Automated Reconciliation

  • Continuous comparison of desired state (Git) vs actual state (cluster)

  • Auto-fix drift if they differ

• Pull-Based Model

  • Cluster pulls changes from Git

  • No direct kubectl apply to production

• Change via Pull Requests

  • Review, approve, audit before deployment

  • Safer and more controlled

• Versioning & Rollback

  • Git history = audit log

  • Easy rollback to last known good commit

• Security & Access Control

  • No human access to production clusters

  • Git permissions define who can change what

• Collaboration

  • Developers, Ops, SREs collaborate via Git workflows

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Imperative vs Declarative Approach (Argo CD Context)

Imperative Approach

• You tell the system step by step

• Example:

  • kubectl create

  • kubectl scale

  • kubectl delete

• Manual and command-driven

• State lives in the cluster, not Git

• Harder to track, audit, and rollback

Declarative Approach (GitOps Way)

• You define the final desired state

• Example:

  • replicas: 3

  • image: app:v1.4.2

• Argo CD figures out how to reach that state

• Git is the source of truth

• Easy rollback, audit, automation

✅ Argo CD is fully declarative by design

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Reconciliation – Meaning (Very Important Concept)

• Reconciliation = Desired State vs Actual State

• Argo CD continuously:

  1. Reads desired state from Git

  2. Reads actual state from Kubernetes

  3. Compares both

  4. Fixes differences automatically or flags them

Why it matters

• Prevents configuration drift

• Recovers from manual or accidental changes

• Keeps environments consistent

• Enables self-healing systems

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GitOps Feature Set (Exam / Interview Points)

• Git as single source of truth

• Automated reconciliation

• Pull-based deployments

• Declarative infrastructure

• Version-controlled changes

• Easy rollback

• Drift detection

• Strong audit trail

• Separation of CI and CD

• Self-service deployments

• Scalable for large environments

• Works across multi-cloud and on-prem

• Enables continuous delivery

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Automated Tools Used in GitOps (Key Ones)

• Argo CD

  • Kubernetes-native GitOps CD

  • Continuous reconciliation

  • Drift detection and auto-sync

• Flux

  • GitOps operator for Kubernetes

  • Pulls changes from Git automatically

• Jenkins X

  • GitOps-driven CI/CD for Kubernetes

  • Environment promotion via Git

• Terraform (with GitOps)

  • Infrastructure as Code

  • Git stores desired infra state

  • Often paired with GitOps workflows