167 lines
3.6 KiB
Markdown
167 lines
3.6 KiB
Markdown
# 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:**
|
|
```bash
|
|
kubectl apply -f deployment.yaml
|
|
kubectl apply -f service.yaml
|
|
```
|
|
|
|
✅ **Correct - ArgoCD Application CR:**
|
|
```bash
|
|
# Only kubectl apply for ArgoCD Application CRs
|
|
kubectl apply -f argocd-application.yaml
|
|
```
|
|
|
|
Then let ArgoCD handle the actual application resources.
|
|
|
|
### Application CR Pattern
|
|
|
|
```yaml
|
|
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
|
|
```bash
|
|
# Modify your Kubernetes manifests or Helm charts in git
|
|
git add k8s/
|
|
git commit -m "update deployment configuration"
|
|
git push
|
|
```
|
|
|
|
### 2. Let ArgoCD Sync
|
|
```bash
|
|
# 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
|
|
```bash
|
|
# 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
|
|
```bash
|
|
# 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
|
|
```bash
|
|
# 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:
|
|
|
|
```bash
|
|
# 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.
|