INIT(repo): apps setup with all user-facing servic

2025-12-17 15:11:34 +09:00
commit 9763b1e682
81 changed files with 3921 additions and 0 deletions
--- a/docusaurus/.gitignore
+++ b/docusaurus/.gitignore
@@ -0,0 +1,20 @@
+# Dependencies
+node_modules/
+package-lock.json
+
+# Production
+build/
+.docusaurus/
+.cache-loader/
+
+# Generated files
+.DS_Store
+Thumbs.db
+
+# Misc
+.env
+.env.local
+.env.*.local
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
--- a/docusaurus/argocd/docusaurus.yaml
+++ b/docusaurus/argocd/docusaurus.yaml
@@ -0,0 +1,53 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: docusaurus
+  namespace: argocd
+  finalizers:
+    - resources-finalizer.argocd.argoproj.io
+spec:
+  project: default
+
+  sources:
+    - repoURL: https://gitea0213.kro.kr/bluemayne/infrastructure.git
+      targetRevision: main
+      path: docusaurus
+
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: docusaurus
+
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+      allowEmpty: false
+
+    syncOptions:
+      - CreateNamespace=true
+      - PrunePropagationPolicy=foreground
+      - PruneLast=true
+
+    retry:
+      limit: 5
+      backoff:
+        duration: 5s
+        factor: 2
+        maxDuration: 3m
+
+  revisionHistoryLimit: 10
+
+  # Ignore differences in checksum annotations and manual restart annotations
+  ignoreDifferences:
+    - group: apps
+      kind: Deployment
+      jqPathExpressions:
+        - .spec.template.metadata.annotations
+        - .metadata.annotations
+
+    - group: ""
+      kind: Service
+      name: docusaurus
+      namespace: docusaurus
+      jsonPointers:
+        - /spec/clusterIP
--- a/docusaurus/blog/2025-12-17-welcome.md
+++ b/docusaurus/blog/2025-12-17-welcome.md
@@ -0,0 +1,25 @@
+---
+slug: welcome
+title: Welcome to Infrastructure Docs
+authors:
+  name: Bluemayne
+  title: Infrastructure Engineer
+tags: [welcome, infrastructure]
+---
+
+# Welcome to Infrastructure Documentation
+
+Welcome to our infrastructure documentation site! This is where we'll document all our infrastructure setup, guides, and best practices.
+
+<!--truncate-->
+
+## What's New
+
+We've just launched this documentation site using Docusaurus. Here you'll find:
+
+- Complete infrastructure setup guides
+- Service documentation
+- Troubleshooting tips
+- Best practices
+
+Stay tuned for more updates!
--- a/docusaurus/deployment.yaml
+++ b/docusaurus/deployment.yaml
@@ -0,0 +1,117 @@
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: docusaurus
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: docusaurus
+  namespace: docusaurus
+  labels:
+    app: docusaurus
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: docusaurus
+  template:
+    metadata:
+      labels:
+        app: docusaurus
+    spec:
+      initContainers:
+      - name: build-docusaurus
+        image: node:18-alpine
+        workingDir: /workspace
+        command:
+        - sh
+        - -c
+        - |
+          apk add --no-cache git
+          echo "Cloning repository..."
+          git clone https://gitea0213.kro.kr/bluemayne/infrastructure.git /tmp/repo
+          cd /tmp/repo/docusaurus
+          echo "Installing dependencies..."
+          npm install --legacy-peer-deps
+          echo "Building Docusaurus site..."
+          npm run build
+          echo "Copying build output..."
+          cp -r build/* /build/
+          echo "Build complete!"
+        volumeMounts:
+        - name: build-output
+          mountPath: /build
+      containers:
+      - name: nginx
+        image: nginx:alpine
+        ports:
+        - containerPort: 80
+          name: http
+        volumeMounts:
+        - name: build-output
+          mountPath: /usr/share/nginx/html
+        - name: nginx-config
+          mountPath: /etc/nginx/conf.d/default.conf
+          subPath: default.conf
+        resources:
+          requests:
+            cpu: 50m
+            memory: 64Mi
+          limits:
+            cpu: 200m
+            memory: 128Mi
+        livenessProbe:
+          httpGet:
+            path: /
+            port: 80
+          initialDelaySeconds: 10
+          periodSeconds: 10
+        readinessProbe:
+          httpGet:
+            path: /
+            port: 80
+          initialDelaySeconds: 5
+          periodSeconds: 5
+      volumes:
+      - name: build-output
+        emptyDir: {}
+      - name: nginx-config
+        configMap:
+          name: nginx-config
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: nginx-config
+  namespace: docusaurus
+data:
+  default.conf: |
+    server {
+        listen 80;
+        server_name _;
+        root /usr/share/nginx/html;
+        index index.html;
+
+        # Enable gzip compression
+        gzip on;
+        gzip_vary on;
+        gzip_min_length 1024;
+        gzip_types text/plain text/css text/xml text/javascript application/x-javascript application/xml+rss application/javascript application/json;
+
+        # SPA fallback
+        location / {
+            try_files $uri $uri/ /index.html;
+        }
+
+        # Cache static assets
+        location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
+            expires 1y;
+            add_header Cache-Control "public, immutable";
+        }
+
+        # Security headers
+        add_header X-Frame-Options "SAMEORIGIN" always;
+        add_header X-Content-Type-Options "nosniff" always;
+        add_header X-XSS-Protection "1; mode=block" always;
+    }
--- a/docusaurus/docs/getting-started/architecture.md
+++ b/docusaurus/docs/getting-started/architecture.md
@@ -0,0 +1,103 @@
+---
+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)
--- a/docusaurus/docs/getting-started/overview.md
+++ b/docusaurus/docs/getting-started/overview.md
@@ -0,0 +1,67 @@
+---
+sidebar_position: 1
+---
+
+# Overview
+
+## Infrastructure at a Glance
+
+Our infrastructure is designed for **high availability**, **automation**, and **easy management**.
+
+### Key Components
+
+#### 🎯 Kubernetes (K3s)
+- Lightweight Kubernetes distribution
+- Running on Oracle Cloud Infrastructure
+- Multi-node cluster for redundancy
+
+#### 🔄 ArgoCD
+- GitOps-based deployment
+- Automatic synchronization from Git
+- Declarative infrastructure management
+
+#### 🔐 Security
+- **cert-manager**: Automatic SSL/TLS certificates
+- **External Secrets**: Vault integration for secrets management
+- **Network Policies**: Fine-grained network access control
+
+#### 📊 Monitoring
+- **Prometheus**: Metrics collection
+- **Grafana**: Visualization and dashboards
+- **Loki**: Log aggregation
+- **Alertmanager**: Alert management
+
+### Infrastructure Layout
+
+```
+┌─────────────────────────────────────────┐
+│          Load Balancer / Ingress        │
+│         (nginx-ingress-controller)      │
+└─────────────────┬───────────────────────┘
+                  │
+       ┌──────────┴──────────┐
+       │                     │
+┌──────▼──────┐    ┌────────▼────────┐
+│   Master    │    │  Worker Nodes   │
+│   Node      │    │                 │
+│             │    │  - Applications │
+│  - Control  │    │  - Services     │
+│    Plane    │    │  - Monitoring   │
+│  - ArgoCD   │    │                 │
+└─────────────┘    └─────────────────┘
+```
+
+### Services Running
+
+| Service | Purpose | URL |
+|---------|---------|-----|
+| Homer | Dashboard | https://homer0213.kro.kr |
+| Gitea | Git Service | https://gitea0213.kro.kr |
+| Grafana | Monitoring | https://grafana0213.kro.kr |
+| Docusaurus | Documentation | https://docusaurus0213.kro.kr |
+
+## Next Steps
+
+- [Learn about the architecture](./architecture)
+- [Explore Kubernetes setup](../services/kubernetes)
+- [Set up monitoring](../services/monitoring)
--- a/docusaurus/docs/intro.md
+++ b/docusaurus/docs/intro.md
@@ -0,0 +1,40 @@
+---
+sidebar_position: 1
+---
+
+# Introduction
+
+Welcome to the **Infrastructure Documentation**!
+
+This documentation site contains comprehensive guides and references for our entire infrastructure setup.
+
+## What's Inside?
+
+- **Getting Started**: Learn about our infrastructure architecture and how to get started
+- **Services**: Detailed documentation for each service we run
+- **Guides**: Step-by-step tutorials and best practices
+- **Blog**: Updates, announcements, and technical insights
+
+## Infrastructure Overview
+
+Our infrastructure is built on:
+
+- **Kubernetes (K3s)**: Container orchestration platform
+- **ArgoCD**: GitOps continuous delivery
+- **Gitea**: Self-hosted Git service
+- **Prometheus & Grafana**: Monitoring and observability
+- **cert-manager**: Automatic SSL certificate management
+
+## Quick Links
+
+- [Architecture Overview](./getting-started/architecture)
+- [Kubernetes Setup](./services/kubernetes)
+- [Monitoring Stack](./services/monitoring)
+
+## Getting Help
+
+If you have questions or need assistance:
+
+1. Check the documentation sections
+2. Search for specific topics
+3. Visit our [Gitea repository](https://gitea0213.kro.kr/bluemayne/infrastructure)
--- a/docusaurus/docs/services/argocd.md
+++ b/docusaurus/docs/services/argocd.md
@@ -0,0 +1,169 @@
+---
+sidebar_position: 2
+---
+
+# ArgoCD
+
+## Overview
+
+**ArgoCD** is our GitOps continuous delivery tool. It automatically synchronizes applications from our Git repository to Kubernetes.
+
+## How It Works
+
+```mermaid
+graph LR
+    A[Git Repository] -->|Watch| B[ArgoCD]
+    B -->|Compare| C[Desired State]
+    B -->|Compare| D[Actual State in K8s]
+    B -->|Sync| E[Deploy Changes]
+```
+
+## Application Structure
+
+Each service has an ArgoCD Application definition:
+
+```yaml
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: example-service
+  namespace: argocd
+spec:
+  project: default
+  source:
+    repoURL: https://gitea0213.kro.kr/bluemayne/infrastructure.git
+    targetRevision: main
+    path: example-service
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: example-service
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+```
+
+## Key Features
+
+### Automated Sync
+
+- **prune: true**: Removes resources deleted from Git
+- **selfHeal: true**: Reverts manual changes to match Git
+- **allowEmpty: false**: Prevents accidental empty deployments
+
+### Manual Operations
+
+```bash
+# List applications
+sudo kubectl get applications -n argocd
+
+# View application status
+sudo kubectl get application -n argocd <app-name> -o yaml
+
+# Force refresh
+argocd app get <app-name> --refresh
+```
+
+## Deployment Workflow
+
+### 1. Make Changes
+
+Edit files in the infrastructure repository:
+
+```bash
+cd /path/to/infrastructure
+vim example-service/deployment.yaml
+git add .
+git commit -m "update deployment"
+git push
+```
+
+### 2. ArgoCD Detects Changes
+
+- Polls Git repository every 3 minutes
+- Or immediately via webhook (if configured)
+
+### 3. Automatic Sync
+
+- Compares desired state (Git) vs actual state (K8s)
+- Applies changes automatically
+- Reports status
+
+### 4. Monitor Deployment
+
+```bash
+# Check application sync status
+sudo kubectl get applications -n argocd
+
+# Watch pod rollout
+sudo kubectl rollout status deployment/<name> -n <namespace>
+```
+
+## Common Patterns
+
+### Adding a New Service
+
+1. Create service directory: `infrastructure/my-service/`
+2. Add Kubernetes manifests
+3. Create kustomization.yaml
+4. Add ArgoCD Application: `infrastructure/my-service/argocd/my-service.yaml`
+5. Reference in main kustomization.yaml
+6. Git push → ArgoCD deploys automatically
+
+### Updating a Service
+
+1. Edit deployment.yaml or other files
+2. Git commit & push
+3. Wait for ArgoCD sync (or force refresh)
+4. Verify deployment
+
+### Rolling Back
+
+```bash
+# Method 1: Git revert
+git revert <commit-hash>
+git push
+
+# Method 2: Sync to specific commit
+argocd app sync <app-name> --revision <commit-hash>
+```
+
+## Troubleshooting
+
+### Sync Stuck
+
+```bash
+# Force hard refresh
+sudo kubectl patch application -n argocd <app-name> \
+  -p '{"metadata": {"annotations": {"argocd.argoproj.io/refresh": "hard"}}}' \
+  --type merge
+```
+
+### Out of Sync
+
+Check what's different:
+
+```bash
+argocd app diff <app-name>
+```
+
+### Sync Failed
+
+View detailed error:
+
+```bash
+sudo kubectl describe application -n argocd <app-name>
+```
+
+## Best Practices
+
+1. **Always use Git**: Don't make manual kubectl changes
+2. **Small commits**: Easier to review and rollback
+3. **Test locally**: Use `kubectl apply --dry-run=client`
+4. **Use pruning**: Keep cluster clean with `prune: true`
+5. **Enable selfHeal**: Prevent configuration drift
+
+## Next Steps
+
+- [Monitoring with Prometheus](./monitoring)
+- [Kubernetes Operations](./kubernetes)
--- a/docusaurus/docs/services/kubernetes.md
+++ b/docusaurus/docs/services/kubernetes.md
@@ -0,0 +1,174 @@
+---
+sidebar_position: 1
+---
+
+# Kubernetes (K3s)
+
+## Overview
+
+We use **K3s**, a lightweight Kubernetes distribution, as our container orchestration platform.
+
+## Cluster Setup
+
+### Nodes
+
+- **Master Node**: `oracle-master`
+  - Control plane components
+  - etcd database
+  - ArgoCD installation
+
+- **Worker Nodes**: `mayne-worker-1`, `mayne-worker-2`, etc.
+  - Application workloads
+  - Monitoring stack
+  - Service deployments
+
+### Access
+
+```bash
+# SSH to master node
+ssh oracle-master
+
+# Use kubectl (requires sudo on master)
+sudo kubectl get nodes
+sudo kubectl get pods -A
+```
+
+## Common Operations
+
+### View All Resources
+
+```bash
+# Get all namespaces
+sudo kubectl get namespaces
+
+# Get all pods in all namespaces
+sudo kubectl get pods -A
+
+# Get services
+sudo kubectl get services -A
+```
+
+### Check Application Status
+
+```bash
+# Check specific namespace
+sudo kubectl get all -n <namespace>
+
+# View pod logs
+sudo kubectl logs -n <namespace> <pod-name>
+
+# Describe pod for troubleshooting
+sudo kubectl describe pod -n <namespace> <pod-name>
+```
+
+### Managing Applications
+
+Most applications are managed by ArgoCD, so manual kubectl operations are rarely needed.
+
+```bash
+# Check ArgoCD applications
+sudo kubectl get applications -n argocd
+
+# Force sync an application (if needed)
+sudo kubectl patch application -n argocd <app-name> \
+  -p '{"metadata": {"annotations": {"argocd.argoproj.io/refresh": "hard"}}}' \
+  --type merge
+```
+
+## Namespaces
+
+Each service runs in its own namespace for isolation:
+
+| Namespace | Purpose |
+|-----------|---------|
+| `argocd` | ArgoCD deployment |
+| `cert-manager` | Certificate management |
+| `ingress-nginx` | Ingress controller |
+| `monitoring` | Prometheus, Grafana |
+| `gitea` | Git service |
+| `vault` | Secrets management |
+
+## Storage
+
+### Storage Classes
+
+- **local-path**: Default storage class
+  - Uses local disk on worker nodes
+  - Good for development and non-critical data
+
+### Persistent Volumes
+
+```bash
+# View PVCs
+sudo kubectl get pvc -A
+
+# View PVs
+sudo kubectl get pv
+```
+
+## Networking
+
+### Ingress
+
+External traffic flows through nginx-ingress-controller:
+
+```
+Internet → nginx-ingress → Service → Pod
+```
+
+### Services
+
+- **ClusterIP**: Internal only (default)
+- **LoadBalancer**: External access (rarely used)
+- **Ingress**: HTTPS with custom domains
+
+## Troubleshooting
+
+### Pod Not Starting
+
+```bash
+# Check pod events
+sudo kubectl describe pod -n <namespace> <pod-name>
+
+# Check logs
+sudo kubectl logs -n <namespace> <pod-name>
+
+# Check previous container logs (if crashed)
+sudo kubectl logs -n <namespace> <pod-name> --previous
+```
+
+### Resource Issues
+
+```bash
+# Check node resources
+sudo kubectl top nodes
+
+# Check pod resources
+sudo kubectl top pods -A
+```
+
+### Network Issues
+
+```bash
+# Check services
+sudo kubectl get svc -A
+
+# Check ingress
+sudo kubectl get ingress -A
+
+# Test connectivity from a pod
+sudo kubectl run -it --rm debug --image=nicolaka/netshoot --restart=Never -- /bin/bash
+```
+
+## Best Practices
+
+1. **Use namespaces** for logical separation
+2. **Set resource limits** on all containers
+3. **Use health checks** (readiness and liveness probes)
+4. **Label everything** for better organization
+5. **Don't run as root** (use securityContext)
+
+## Next Steps
+
+- [ArgoCD Setup](./argocd)
+- [Monitoring Stack](./monitoring)
--- a/docusaurus/docs/services/monitoring.md
+++ b/docusaurus/docs/services/monitoring.md
@@ -0,0 +1,225 @@
+---
+sidebar_position: 3
+---
+
+# Monitoring Stack
+
+## Overview
+
+Our monitoring stack provides complete observability with metrics, logs, and visualization.
+
+## Components
+
+### Prometheus
+
+**Metrics collection and storage**
+
+- Scrapes metrics from all services
+- Stores time-series data
+- Powers alerting rules
+
+Access: Internal only (no direct UI exposure)
+
+### Grafana
+
+**Visualization and dashboards**
+
+- Beautiful dashboards
+- Query Prometheus data
+- Alert management UI
+
+Access: https://grafana0213.kro.kr
+
+### Loki
+
+**Log aggregation**
+
+- Collects logs from all pods
+- Indexed for fast searching
+- Integrated with Grafana
+
+### Promtail
+
+**Log shipping agent**
+
+- Runs on each node
+- Forwards logs to Loki
+- Adds metadata labels
+
+### Alertmanager
+
+**Alert routing and notification**
+
+- Receives alerts from Prometheus
+- Routes to correct channels
+- Deduplication and grouping
+
+## Dashboards
+
+### Pre-built Dashboards
+
+1. **Cluster Overview**
+   - Node health
+   - Resource usage
+   - Pod status
+
+2. **Application Metrics**
+   - Request rate
+   - Error rate
+   - Response time
+
+3. **Infrastructure**
+   - CPU, Memory, Disk
+   - Network traffic
+   - Storage usage
+
+### Creating Custom Dashboards
+
+```bash
+# Export existing dashboard
+curl -s http://grafana:3000/api/dashboards/uid/<uid> > dashboard.json
+
+# Import via UI
+Grafana → Dashboards → Import → Upload JSON
+```
+
+## Querying Metrics
+
+### PromQL Examples
+
+```promql
+# CPU usage by pod
+rate(container_cpu_usage_seconds_total[5m])
+
+# Memory usage
+container_memory_working_set_bytes
+
+# HTTP request rate
+rate(http_requests_total[5m])
+
+# Error rate
+rate(http_requests_total{status=~"5.."}[5m])
+```
+
+## Alerts
+
+### Viewing Alerts
+
+```bash
+# List Prometheus rules
+sudo kubectl get prometheusrules -n monitoring
+
+# View Alertmanager status
+sudo kubectl get alertmanagers -n monitoring
+```
+
+### Common Alerts
+
+- **HighCPUUsage**: Pod using >80% CPU
+- **HighMemoryUsage**: Pod using >80% memory
+- **PodCrashLooping**: Pod restarting frequently
+- **DiskSpaceLow**: Node disk >85% full
+
+## Log Queries
+
+### LogQL Examples
+
+```logql
+# All logs from a namespace
+{namespace="my-app"}
+
+# Error logs
+{namespace="my-app"} |= "error"
+
+# Parse JSON logs
+{namespace="my-app"} | json | level="error"
+
+# Count errors
+count_over_time({namespace="my-app"} |= "error" [5m])
+```
+
+## Accessing Monitoring Data
+
+### Grafana UI
+
+1. Navigate to https://grafana0213.kro.kr
+2. Log in with credentials
+3. Browse dashboards or create queries
+
+### Port Forwarding (Development)
+
+```bash
+# Prometheus UI
+sudo kubectl port-forward -n monitoring svc/prometheus-operated 9090:9090
+
+# Access at http://localhost:9090
+
+# Alertmanager UI
+sudo kubectl port-forward -n monitoring svc/alertmanager-operated 9093:9093
+
+# Access at http://localhost:9093
+```
+
+## Troubleshooting
+
+### No Metrics Showing
+
+```bash
+# Check Prometheus targets
+sudo kubectl exec -n monitoring prometheus-0 -- promtool check config /etc/prometheus/prometheus.yml
+
+# Verify service monitors
+sudo kubectl get servicemonitors -A
+```
+
+### Grafana Not Loading Data
+
+```bash
+# Check Grafana logs
+sudo kubectl logs -n monitoring deployment/grafana
+
+# Verify datasource configuration
+sudo kubectl get secret -n monitoring grafana-datasources -o yaml
+```
+
+### High Cardinality Issues
+
+Too many unique label combinations can cause performance issues:
+
+```bash
+# Check series count
+curl http://prometheus:9090/api/v1/status/tsdb | jq '.data.seriesCountByMetricName'
+```
+
+## Best Practices
+
+1. **Set up alerts proactively**: Don't wait for incidents
+2. **Use labels wisely**: Avoid high cardinality
+3. **Create focused dashboards**: One purpose per dashboard
+4. **Set retention policies**: Balance storage vs history
+5. **Document custom metrics**: Help future maintainers
+
+## Metrics to Monitor
+
+### Application Level
+- Request rate
+- Error rate
+- Response time (latency)
+- Saturation (queue depth)
+
+### Infrastructure Level
+- CPU usage
+- Memory usage
+- Disk I/O
+- Network throughput
+
+### Business Level (Optional)
+- User signups
+- Active sessions
+- Feature usage
+- Transaction volume
+
+## Next Steps
+
+- [Kubernetes Operations](./kubernetes)
+- [ArgoCD Configuration](./argocd)
--- a/docusaurus/docusaurus.config.js
+++ b/docusaurus/docusaurus.config.js
@@ -0,0 +1,146 @@
+// @ts-check
+// `@type` JSDoc annotations allow editor autocompletion and type checking
+// (when paired with `@ts-check`).
+// There are various equivalent ways to declare your Docusaurus config.
+// See: https://docusaurus.io/docs/api/docusaurus-config
+
+import {themes as prismThemes} from 'prism-react-renderer';
+
+/** @type {import('@docusaurus/types').Config} */
+const config = {
+  title: 'Infrastructure Documentation',
+  tagline: 'Complete guide to our infrastructure and services',
+  favicon: 'img/favicon.ico',
+
+  // Set the production url of your site here
+  url: 'https://docusaurus0213.kro.kr',
+  // Set the /<baseUrl>/ pathname under which your site is served
+  // For GitHub pages deployment, it is often '/<projectName>/'
+  baseUrl: '/',
+
+  // GitHub pages deployment config.
+  // If you aren't using GitHub pages, you don't need these.
+  organizationName: 'bluemayne', // Usually your GitHub org/user name.
+  projectName: 'infrastructure', // Usually your repo name.
+
+  onBrokenLinks: 'warn',
+  onBrokenMarkdownLinks: 'warn',
+
+  // Even if you don't use internationalization, you can use this field to set
+  // useful metadata like html lang. For example, if your site is Chinese, you
+  // may want to replace "en" with "zh-Hans".
+  i18n: {
+    defaultLocale: 'ko',
+    locales: ['ko', 'en'],
+  },
+
+  presets: [
+    [
+      'classic',
+      /** @type {import('@docusaurus/preset-classic').Options} */
+      ({
+        docs: {
+          routeBasePath: '/', // Serve docs at the site's root
+          sidebarPath: './sidebars.js',
+          // Please change this to your repo.
+          // Remove this to remove the "edit this page" links.
+          editUrl:
+            'https://gitea0213.kro.kr/bluemayne/infrastructure/src/branch/main/docusaurus/',
+        },
+        blog: {
+          showReadingTime: true,
+          // Please change this to your repo.
+          // Remove this to remove the "edit this page" links.
+          editUrl:
+            'https://gitea0213.kro.kr/bluemayne/infrastructure/src/branch/main/docusaurus/',
+        },
+        theme: {
+          customCss: './src/css/custom.css',
+        },
+      }),
+    ],
+  ],
+
+  themeConfig:
+    /** @type {import('@docusaurus/preset-classic').ThemeConfig} */
+    ({
+      // Replace with your project's social card
+      image: 'img/docusaurus-social-card.jpg',
+      navbar: {
+        title: 'Infrastructure Docs',
+        logo: {
+          alt: 'Infrastructure Logo',
+          src: 'img/logo.svg',
+        },
+        items: [
+          {
+            type: 'docSidebar',
+            sidebarId: 'tutorialSidebar',
+            position: 'left',
+            label: 'Documentation',
+          },
+          {to: '/blog', label: 'Blog', position: 'left'},
+          {
+            type: 'localeDropdown',
+            position: 'right',
+          },
+          {
+            href: 'https://gitea0213.kro.kr/bluemayne/infrastructure',
+            label: 'Gitea',
+            position: 'right',
+          },
+        ],
+      },
+      footer: {
+        style: 'dark',
+        links: [
+          {
+            title: 'Docs',
+            items: [
+              {
+                label: 'Documentation',
+                to: '/docs/intro',
+              },
+            ],
+          },
+          {
+            title: 'Services',
+            items: [
+              {
+                label: 'Homer',
+                href: 'https://homer0213.kro.kr',
+              },
+              {
+                label: 'Gitea',
+                href: 'https://gitea0213.kro.kr',
+              },
+              {
+                label: 'Grafana',
+                href: 'https://grafana0213.kro.kr',
+              },
+            ],
+          },
+          {
+            title: 'More',
+            items: [
+              {
+                label: 'Blog',
+                to: '/blog',
+              },
+              {
+                label: 'Repository',
+                href: 'https://gitea0213.kro.kr/bluemayne/infrastructure',
+              },
+            ],
+          },
+        ],
+        copyright: `Copyright © ${new Date().getFullYear()} Infrastructure Documentation. Built with Docusaurus.`,
+      },
+      prism: {
+        theme: prismThemes.github,
+        darkTheme: prismThemes.dracula,
+      },
+    }),
+};
+
+export default config;
--- a/docusaurus/ingress.yaml
+++ b/docusaurus/ingress.yaml
@@ -0,0 +1,27 @@
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: docusaurus
+  namespace: docusaurus
+  annotations:
+    cert-manager.io/cluster-issuer: "letsencrypt-prod"
+    nginx.ingress.kubernetes.io/proxy-body-size: "0"
+    nginx.ingress.kubernetes.io/proxy-read-timeout: "600"
+    nginx.ingress.kubernetes.io/proxy-send-timeout: "600"
+spec:
+  ingressClassName: nginx
+  tls:
+  - hosts:
+    - docusaurus0213.kro.kr
+    secretName: docusaurus-tls
+  rules:
+  - host: docusaurus0213.kro.kr
+    http:
+      paths:
+      - path: /
+        pathType: Prefix
+        backend:
+          service:
+            name: docusaurus
+            port:
+              number: 80
--- a/docusaurus/kustomization.yaml
+++ b/docusaurus/kustomization.yaml
@@ -0,0 +1,11 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+resources:
+  # ArgoCD Application 리소스는 infrastructure/kustomization.yaml에서 관리
+  # - argocd/docusaurus.yaml
+  - deployment.yaml
+  - service.yaml
+  - ingress.yaml
+
+namespace: docusaurus
--- a/docusaurus/package.json
+++ b/docusaurus/package.json
@@ -0,0 +1,44 @@
+{
+  "name": "infrastructure-docs",
+  "version": "1.0.0",
+  "private": true,
+  "scripts": {
+    "docusaurus": "docusaurus",
+    "start": "docusaurus start",
+    "build": "docusaurus build",
+    "swizzle": "docusaurus swizzle",
+    "deploy": "docusaurus deploy",
+    "clear": "docusaurus clear",
+    "serve": "docusaurus serve",
+    "write-translations": "docusaurus write-translations",
+    "write-heading-ids": "docusaurus write-heading-ids"
+  },
+  "dependencies": {
+    "@docusaurus/core": "^3.1.0",
+    "@docusaurus/preset-classic": "^3.1.0",
+    "@mdx-js/react": "^3.0.0",
+    "clsx": "^2.0.0",
+    "prism-react-renderer": "^2.3.0",
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0"
+  },
+  "devDependencies": {
+    "@docusaurus/module-type-aliases": "^3.1.0",
+    "@docusaurus/types": "^3.1.0"
+  },
+  "browserslist": {
+    "production": [
+      ">0.5%",
+      "not dead",
+      "not op_mini all"
+    ],
+    "development": [
+      "last 1 chrome version",
+      "last 1 firefox version",
+      "last 1 safari version"
+    ]
+  },
+  "engines": {
+    "node": ">=18.0"
+  }
+}
--- a/docusaurus/service.yaml
+++ b/docusaurus/service.yaml
@@ -0,0 +1,16 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: docusaurus
+  namespace: docusaurus
+  labels:
+    app: docusaurus
+spec:
+  type: ClusterIP
+  ports:
+  - name: http
+    port: 80
+    targetPort: 80
+    protocol: TCP
+  selector:
+    app: docusaurus
--- a/docusaurus/sidebars.js
+++ b/docusaurus/sidebars.js
@@ -0,0 +1,45 @@
+/**
+ * Creating a sidebar enables you to:
+ - create an ordered group of docs
+ - render a sidebar for each doc of that group
+ - provide next/previous navigation
+
+ The sidebars can be generated from the filesystem, or explicitly defined here.
+
+ Create as many sidebars as you want.
+ */
+
+// @ts-check
+
+/** @type {import('@docusaurus/plugin-content-docs').SidebarsConfig} */
+const sidebars = {
+  // By default, Docusaurus generates a sidebar from the docs folder structure
+  tutorialSidebar: [
+    'intro',
+    {
+      type: 'category',
+      label: 'Getting Started',
+      items: ['getting-started/overview', 'getting-started/architecture'],
+    },
+    {
+      type: 'category',
+      label: 'Services',
+      items: ['services/kubernetes', 'services/argocd', 'services/monitoring'],
+    },
+  ],
+
+  // But you can create a sidebar manually
+  /*
+  tutorialSidebar: [
+    'intro',
+    'hello',
+    {
+      type: 'category',
+      label: 'Tutorial',
+      items: ['tutorial-basics/create-a-document'],
+    },
+  ],
+   */
+};
+
+export default sidebars;
--- a/docusaurus/src/css/custom.css
+++ b/docusaurus/src/css/custom.css
@@ -0,0 +1,30 @@
+/**
+ * Any CSS included here will be global. The classic template
+ * bundles Infima by default. Infima is a CSS framework designed to
+ * work well for content-centric websites.
+ */
+
+/* You can override the default Infima variables here. */
+:root {
+  --ifm-color-primary: #2e8555;
+  --ifm-color-primary-dark: #29784c;
+  --ifm-color-primary-darker: #277148;
+  --ifm-color-primary-darkest: #205d3b;
+  --ifm-color-primary-light: #33925d;
+  --ifm-color-primary-lighter: #359962;
+  --ifm-color-primary-lightest: #3cad6e;
+  --ifm-code-font-size: 95%;
+  --docusaurus-highlighted-code-line-bg: rgba(0, 0, 0, 0.1);
+}
+
+/* For readability concerns, you should choose a lighter palette in dark mode. */
+[data-theme='dark'] {
+  --ifm-color-primary: #25c2a0;
+  --ifm-color-primary-dark: #21af90;
+  --ifm-color-primary-darker: #1fa588;
+  --ifm-color-primary-darkest: #1a8870;
+  --ifm-color-primary-light: #29d5b0;
+  --ifm-color-primary-lighter: #32d8b4;
+  --ifm-color-primary-lightest: #4fddbf;
+  --docusaurus-highlighted-code-line-bg: rgba(0, 0, 0, 0.3);
+}