GitOps Workflow

Complete guide to implementing GitOps workflows with ArgoCD and Flux for automated Kubernetes deployments.

Purpose

Implement declarative, Git-based continuous delivery for Kubernetes using ArgoCD or Flux CD, following OpenGitOps principles.

When to Use This Skill

• Set up GitOps for Kubernetes clusters
• Automate application deployments from Git
• Implement progressive delivery strategies
• Manage multi-cluster deployments
• Configure automated sync policies
• Set up secret management in GitOps

OpenGitOps Principles

1. Declarative - Entire system described declaratively
2. Versioned and Immutable - Desired state stored in Git
3. Pulled Automatically - Software agents pull desired state
4. Continuously Reconciled - Agents reconcile actual vs desired state

ArgoCD Setup

1. Installation

# Create namespace
kubectl create namespace argocd

# Install ArgoCD
kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

# Get admin password
kubectl -n argocd get secret argocd-initial-admin-secret -o jsonpath="{.data.password}" | base64 -d

Reference: See references/argocd-setup.md for detailed setup

2. Repository Structure

gitops-repo/
├── apps/
│   ├── production/
│   │   ├── app1/
│   │   │   ├── kustomization.yaml
│   │   │   └── deployment.yaml
│   │   └── app2/
│   └── staging/
├── infrastructure/
│   ├── ingress-nginx/
│   ├── cert-manager/
│   └── monitoring/
└── argocd/
    ├── applications/
    └── projects/

3. Create Application

# argocd/applications/my-app.yaml
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: my-app
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/org/gitops-repo
    targetRevision: main
    path: apps/production/my-app
  destination:
    server: https://kubernetes.default.svc
    namespace: production
  syncPolicy:
    automated:
      prune: true
      selfHeal: true
    syncOptions:
      - CreateNamespace=true

4. App of Apps Pattern

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: applications
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/org/gitops-repo
    targetRevision: main
    path: argocd/applications
  destination:
    server: https://kubernetes.default.svc
    namespace: argocd
  syncPolicy:
    automated: {}

Flux CD Setup

1. Installation

The example uses Homebrew. For other systems, follow the official Flux installation guide.

# Install the Flux CLI with Homebrew
brew install fluxcd/tap/flux
flux check --pre

# Bootstrap Flux
flux bootstrap github \
  --owner=org \
  --repository=gitops-repo \
  --branch=main \
  --path=clusters/production \
  --personal

2. Create GitRepository

apiVersion: source.toolkit.fluxcd.io/v1
kind: GitRepository
metadata:
  name: my-app
  namespace: flux-system
spec:
  interval: 1m
  url: https://github.com/org/my-app
  ref:
    branch: main

3. Create Kustomization

apiVersion: kustomize.toolkit.fluxcd.io/v1
kind: Kustomization
metadata:
  name: my-app
  namespace: flux-system
spec:
  interval: 5m
  path: ./deploy
  prune: true
  sourceRef:
    kind: GitRepository
    name: my-app

Sync Policies

Auto-Sync Configuration

ArgoCD:

syncPolicy:
  automated:
    prune: true # Delete resources not in Git
    selfHeal: true # Reconcile manual changes
    allowEmpty: false
  retry:
    limit: 5
    backoff:
      duration: 5s
      factor: 2
      maxDuration: 3m

Flux:

spec:
  interval: 1m
  prune: true
  wait: true
  timeout: 5m

Reference: See references/sync-policies.md

Progressive Delivery

Canary Deployment with ArgoCD Rollouts

apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: my-app
spec:
  replicas: 5
  strategy:
    canary:
      steps:
        - setWeight: 20
        - pause: { duration: 1m }
        - setWeight: 50
        - pause: { duration: 2m }
        - setWeight: 100

Blue-Green Deployment

strategy:
  blueGreen:
    activeService: my-app
    previewService: my-app-preview
    autoPromotionEnabled: false

Secret Management

External Secrets Operator

apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: db-credentials
spec:

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