ArgoCD Management Best Practices

This skill provides ArgoCD application management patterns.

When to Use

Activates when:

• Working with ArgoCD-managed applications
• Creating or modifying Kubernetes resources in ArgoCD repos
• Deploying applications via ArgoCD

Core Principle

Never manually create/modify Kubernetes resources when using ArgoCD.

ArgoCD manages the lifecycle of your Kubernetes resources. Manual kubectl operations will be overwritten by ArgoCD's sync process.

The ArgoCD Way

Creating Resources

❌ Wrong - Manual kubectl:

kubectl apply -f deployment.yaml
kubectl apply -f service.yaml

✅ Correct - ArgoCD Application CR:

# Only kubectl apply for ArgoCD Application CRs
kubectl apply -f argocd-application.yaml

Then let ArgoCD handle the actual application resources.

Application CR Pattern

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: my-app
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/org/repo
    targetRevision: HEAD
    path: k8s/manifests
  destination:
    server: https://kubernetes.default.svc
    namespace: my-app
  syncPolicy:
    automated:
      prune: true
      selfHeal: true

Workflow

1. Update Source Repository

# Modify your Kubernetes manifests or Helm charts in git
git add k8s/
git commit -m "update deployment configuration"
git push

2. Let ArgoCD Sync

# ArgoCD automatically detects changes and syncs

# Or manually trigger sync
argocd app sync my-app

# Check sync status
argocd app get my-app

3. Verify Deployment

# Use kubectl for read-only operations
kubectl get pods -n my-app
kubectl logs -n my-app deployment/my-app
kubectl describe deployment -n my-app my-app

ArgoCD CLI Commands

Application Management

# List applications
argocd app list

# Get application details
argocd app get my-app

# Sync application
argocd app sync my-app

# Check sync status
argocd app wait my-app --health

# View application logs
argocd app logs my-app

# Diff current state vs desired
argocd app diff my-app

Debugging

# See why sync failed
argocd app get my-app

# View events
kubectl get events -n my-app

# Check ArgoCD controller logs
kubectl logs -n argocd deployment/argocd-application-controller

Best Practices

✅ Do:

• Use kubectl apply -f ONLY for ArgoCD Application CRs
• Let ArgoCD handle all application resources
• Use git as the single source of truth
• Use automated sync policies for continuous deployment
• Use read-only kubectl commands for debugging

❌ Don't:

• Manually create/modify Kubernetes resources with kubectl
• Edit resources directly with kubectl edit
• Use kubectl apply for app resources in ArgoCD-managed namespaces
• Fight with ArgoCD by manually changing resources

GitOps Workflow

1. Code Change → Commit to git repository
2. ArgoCD Detects → Automatic or manual sync trigger
3. ArgoCD Applies → Resources created/updated in cluster
4. ArgoCD Monitors → Health and sync status tracked
5. Self-Heal → Auto-corrects manual changes (if enabled)

Emergency Override

If you absolutely must make a manual change:

# 1. Pause auto-sync temporarily
argocd app set my-app --sync-policy none

# 2. Make your manual change
kubectl apply -f emergency-fix.yaml

# 3. Update git to match your change
git add k8s/emergency-fix.yaml
git commit -m "emergency fix applied"
git push

# 4. Re-enable auto-sync
argocd app set my-app --sync-policy automated

But prefer: Make the change in git first, then let ArgoCD apply it.