Mayne0213
42eb875c01
- Update repository URL to K3S-HOME organization - Change from personal to organization repo
170 lines
3.4 KiB
Markdown
170 lines
3.4 KiB
Markdown
---
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sidebar_position: 2
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---
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# ArgoCD
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## Overview
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**ArgoCD** is our GitOps continuous delivery tool. It automatically synchronizes applications from our Git repository to Kubernetes.
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## How It Works
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```mermaid
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graph LR
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A[Git Repository] -->|Watch| B[ArgoCD]
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B -->|Compare| C[Desired State]
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B -->|Compare| D[Actual State in K8s]
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B -->|Sync| E[Deploy Changes]
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```
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## Application Structure
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Each service has an ArgoCD Application definition:
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```yaml
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apiVersion: argoproj.io/v1alpha1
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kind: Application
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metadata:
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name: example-service
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namespace: argocd
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spec:
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project: default
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source:
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repoURL: https://github.com/K3S-HOME/infrastructure.git
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targetRevision: main
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path: example-service
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destination:
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server: https://kubernetes.default.svc
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namespace: example-service
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syncPolicy:
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automated:
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prune: true
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selfHeal: true
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```
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## Key Features
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### Automated Sync
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- **prune: true**: Removes resources deleted from Git
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- **selfHeal: true**: Reverts manual changes to match Git
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- **allowEmpty: false**: Prevents accidental empty deployments
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### Manual Operations
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```bash
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# List applications
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sudo kubectl get applications -n argocd
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# View application status
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sudo kubectl get application -n argocd <app-name> -o yaml
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# Force refresh
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argocd app get <app-name> --refresh
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```
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## Deployment Workflow
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### 1. Make Changes
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Edit files in the infrastructure repository:
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```bash
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cd /path/to/infrastructure
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vim example-service/deployment.yaml
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git add .
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git commit -m "update deployment"
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git push
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```
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### 2. ArgoCD Detects Changes
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- Polls Git repository every 3 minutes
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- Or immediately via webhook (if configured)
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### 3. Automatic Sync
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- Compares desired state (Git) vs actual state (K8s)
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- Applies changes automatically
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- Reports status
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### 4. Monitor Deployment
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```bash
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# Check application sync status
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sudo kubectl get applications -n argocd
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# Watch pod rollout
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sudo kubectl rollout status deployment/<name> -n <namespace>
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```
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## Common Patterns
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### Adding a New Service
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1. Create service directory: `infrastructure/my-service/`
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2. Add Kubernetes manifests
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3. Create kustomization.yaml
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4. Add ArgoCD Application: `infrastructure/my-service/argocd/my-service.yaml`
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5. Reference in main kustomization.yaml
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6. Git push → ArgoCD deploys automatically
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### Updating a Service
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1. Edit deployment.yaml or other files
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2. Git commit & push
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3. Wait for ArgoCD sync (or force refresh)
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4. Verify deployment
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### Rolling Back
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```bash
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# Method 1: Git revert
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git revert <commit-hash>
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git push
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# Method 2: Sync to specific commit
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argocd app sync <app-name> --revision <commit-hash>
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```
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## Troubleshooting
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### Sync Stuck
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```bash
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# Force hard refresh
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sudo kubectl patch application -n argocd <app-name> \
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-p '{"metadata": {"annotations": {"argocd.argoproj.io/refresh": "hard"}}}' \
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--type merge
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```
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### Out of Sync
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Check what's different:
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```bash
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argocd app diff <app-name>
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```
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### Sync Failed
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View detailed error:
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```bash
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sudo kubectl describe application -n argocd <app-name>
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```
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## Best Practices
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1. **Always use Git**: Don't make manual kubectl changes
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2. **Small commits**: Easier to review and rollback
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3. **Test locally**: Use `kubectl apply --dry-run=client`
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4. **Use pruning**: Keep cluster clean with `prune: true`
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5. **Enable selfHeal**: Prevent configuration drift
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## Next Steps
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- [Monitoring with Prometheus](./monitoring)
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- [Kubernetes Operations](./kubernetes)
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