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docusaurus/asset/docs/getting-started/architecture.md

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+---
+sidebar_position: 2
+---
+
+# Architecture
+
+## System Architecture
+
+Our infrastructure follows modern DevOps practices with GitOps at its core.
+
+### GitOps Workflow
+
+```mermaid
+graph LR
+    A[Developer] -->|Git Push| B[Gitea]
+    B -->|Webhook| C[ArgoCD]
+    C -->|Deploy| D[Kubernetes]
+    D -->|Metrics| E[Prometheus]
+    E -->|Visualize| F[Grafana]
+```
+
+### Network Architecture
+
+#### Ingress Layer
+- **nginx-ingress-controller**: Routes external traffic
+- **cert-manager**: Manages SSL certificates via Let's Encrypt
+- **DNS**: kro.kr domain with wildcard support
+
+#### Application Layer
+- Each service runs in its own namespace
+- Resource limits and requests defined
+- Health checks and readiness probes
+
+#### Data Layer
+- **PostgreSQL**: Primary database for Gitea, Grafana
+- **Persistent Volumes**: Using local-path provisioner
+- **Backup**: Automated backups to S3-compatible storage (MinIO)
+
+### Security Architecture
+
+```yaml
+Security Layers:
+  1. Network Level:
+     - Ingress with TLS termination
+     - Network policies between namespaces
+
+  2. Application Level:
+     - External Secrets for sensitive data
+     - HashiCorp Vault integration
+     - Secret rotation policies
+
+  3. Access Control:
+     - RBAC for Kubernetes
+     - SSO integration (future)
+     - Audit logging
+```
+
+## Design Principles
+
+### 1. Everything as Code
+- Infrastructure: Kubernetes YAML
+- Configuration: Kustomize
+- Secrets: External Secrets Operator
+- Monitoring: Prometheus rules as code
+
+### 2. GitOps First
+- Single source of truth: Git repository
+- Automatic synchronization via ArgoCD
+- Rollback capability through Git history
+
+### 3. Observability
+- Metrics: Prometheus
+- Logs: Loki
+- Traces: (Future: Jaeger/Tempo)
+- Dashboards: Grafana
+
+### 4. High Availability
+- Multi-node Kubernetes cluster
+- Replicated stateful services
+- Automated failover
+
+## Technology Stack
+
+| Layer | Technology |
+|-------|-----------|
+| Container Orchestration | Kubernetes (K3s) |
+| GitOps | ArgoCD |
+| Service Mesh | (Future: Istio/Linkerd) |
+| Ingress | nginx-ingress |
+| Certificate Management | cert-manager |
+| Secrets Management | External Secrets + Vault |
+| Monitoring | Prometheus + Grafana |
+| Logging | Loki + Promtail |
+| Storage | local-path, MinIO |
+| Database | PostgreSQL |
+| Git | Gitea |
+| Documentation | Docusaurus |
+
+## Further Reading
+
+- [Kubernetes Setup Details](../services/kubernetes)
+- [ArgoCD Configuration](../services/argocd)
+- [Monitoring Stack](../services/monitoring)