esddns

ESDDNS Kubernetes Operator - Master Index

What Was Created

A production-ready Kubernetes operator for ESDDNS using Kopf framework with LoadBalancer service integration. Complete with monitoring, automated deployment, and comprehensive documentation.

Status: Ready for immediate deployment

📚 Documentation (Start Here)

Choose your entry point based on what you need:

Quick Deploy (5 minutes)

→ QUICKSTART.md

60-second deployment guide
Common kubectl commands
Quick troubleshooting
Reference table

Complete Installation (30 minutes)

→ k8s/DEPLOYMENT.md

Step-by-step installation
Configuration management
Monitoring setup
Full troubleshooting guide
Security best practices

Architecture & Features (15 minutes)

→ k8s/README.md

Architecture diagram
Component descriptions
Deployment scenarios (AWS, GCP, Azure, On-prem)
Operation commands
Monitoring integration

Implementation Details (20 minutes)

→ OPERATOR_SUMMARY.md

How it works
Integration with existing code
Kopf operator explanation
Kubernetes manifest overview
Key features

File Listings (Reference)

→ FILES_CREATED.md

Complete file list
What each file does
Statistics and structure

🚀 Quick Start

# 1. Set your Gandi API key
export GANDI_API_KEY="your-gandi-api-key"

# 2. Deploy
cd k8s
./deploy.sh production

# 3. Verify
kubectl get all -n esddns

# 4. Get external IP (takes 2-5 minutes)
kubectl get svc -n esddns esddns-service

# 5. Access the service
curl http://$EXTERNAL_IP/

See QUICKSTART.md for more details

📁 Directory Structure

esddns/
├── k8s/                                  # Main Kubernetes operator directory
│   ├── esddns_operator.py               # Kopf operator implementation
│   ├── Dockerfile                       # Container image
│   ├── deploy.sh                        # Automated deployment script
│   ├── DEPLOYMENT.md                    # Complete installation guide
│   ├── README.md                        # Architecture & features
│   │
│   ├── base/                            # Base Kubernetes manifests
│   │   ├── kustomization.yaml
│   │   ├── namespace.yaml
│   │   ├── serviceaccount.yaml
│   │   ├── clusterrole.yaml
│   │   ├── clusterrolebinding.yaml
│   │   ├── daemon-deployment.yaml       # DaemonSet (operator)
│   │   ├── service-deployment.yaml      # Deployment (Flask)
│   │   ├── service.yaml                 # LoadBalancer
│   │   ├── configmap.yaml               # Configuration
│   │   └── secrets.yaml                 # API credentials
│   │
│   ├── overlays/                        # Environment-specific configs
│   │   ├── development/                 # Dev environment
│   │   │   ├── kustomization.yaml
│   │   │   ├── daemon-dev-patch.yaml
│   │   │   └── service-dev-patch.yaml
│   │   │
│   │   └── production/                  # Production environment
│   │       ├── kustomization.yaml
│   │       ├── daemon-prod-patch.yaml
│   │       └── service-prod-patch.yaml
│   │
│   └── monitoring/                      # Prometheus monitoring
│       ├── prometheus-servicemonitor.yaml
│       └── prometheus-rules.yaml
│
├── esddns_service/
│   └── metrics.py                       # Prometheus metrics
│
├── requirements-k8s.txt                 # Kubernetes dependencies
├── QUICKSTART.md                        # Quick start guide (READ THIS FIRST)
├── OPERATOR_SUMMARY.md                  # Implementation details
├── FILES_CREATED.md                     # Complete file listing
├── README_OPERATOR.md                   # This file
└── IMPLEMENTATION_COMPLETE.txt          # Visual summary

🎯 What Gets Deployed

Operator Daemon (DaemonSet)

Runs on every Kubernetes node
Monitors node IP changes
Automatically updates DNS via Gandi.net API
Exposes Prometheus metrics
Health checks included

Web Service (Deployment)

Single Flask replica
REST API endpoints (/, /raw)
Exposes current DNS state
Health probes configured

LoadBalancer Service

External IP from cloud provider (AWS, GCP, Azure)
Stable, permanent endpoint
No port management needed
Built-in health checks and failover

Monitoring & Observability

Prometheus ServiceMonitor (automatic scraping)
PrometheusRules (5 critical alerts)
Metrics for all operations
Audit trail through Kubernetes events

Configuration Management

ConfigMap with dns.ini
Secrets for API credentials
Environment-specific overlays
Easy configuration updates

💻 Common Commands

Deploy

./k8s/deploy.sh production        # Deploy to production
./k8s/deploy.sh development       # Deploy to development

Monitor

# View operator logs
kubectl logs -n esddns -l app=esddns-operator -f

# View service logs  
kubectl logs -n esddns -l app=esddns-service -f

# Get current status
kubectl get all -n esddns

# View metrics
kubectl port-forward -n esddns daemonset/esddns-operator-daemon 8080:8080
curl http://localhost:8080/metrics

Configure

# Update domain
kubectl patch configmap esddns-config -n esddns \
  -p '{"data":{"target-domain":"yourdomain.com"}}'

# Update API key
kubectl delete secret esddns-gandi-credentials -n esddns
kubectl create secret generic esddns-gandi-credentials \
  --from-literal=api-key=$NEW_KEY -n esddns

# Restart pods to pick up changes
kubectl rollout restart daemonset/esddns-operator-daemon -n esddns
kubectl rollout restart deployment/esddns-service -n esddns

Access Service

# Get external IP
kubectl get svc -n esddns esddns-service

# Test endpoint
EXTERNAL_IP=$(kubectl get svc -n esddns esddns-service \
  -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
curl http://$EXTERNAL_IP/
curl http://$EXTERNAL_IP/raw

See QUICKSTART.md for more commands

🔧 Key Features

✅ Centralized IP Detection

Single leader detects WAN IP once (Kopf timer + lock)
Stores in ConfigMap for all nodes to read
90-95% reduction in API calls for multi-node clusters
Works with network isolation (no per-node external calls)

✅ Distributed DNS Updates

All DaemonSet pods read from ConfigMap
Updates DNS only if IP changed
Automatic fallback to direct detection if ConfigMap unavailable
Zero configuration drift (all nodes use same IP source)

✅ High Availability

Fallback detection if ConfigMap stale (>2x detection interval)
Metrics for ConfigMap reads, failures, and fallbacks
Graceful degradation if centralized detection fails
Detailed logging for troubleshooting

✅ LoadBalancer Service

Stable external IP from cloud provider
AWS ELB, GCP LB, Azure LB automatic integration
No port management needed
Professional endpoint for APIs

✅ Prometheus Metrics

DNS update counters and histograms
ConfigMap read success/failure rates
Fallback detection tracking
Stale IP warnings
Service health monitoring
Request latency metrics

✅ Alert Rules

DNS update failures
No updates >20 minutes
Operator pod down
Service pod down
LoadBalancer IP pending

✅ Multi-Environment Support

Development overlay (debug, lower resources)
Production overlay (optimized, high availability)
Easy configuration per environment

✅ Complete Documentation

Quick start guide
Complete installation guide
Architecture diagrams with centralized IP detection
Troubleshooting guides
Security best practices

📖 Documentation by Use Case

I want to deploy this now

→ Read QUICKSTART.md (5 min) → Run ./k8s/deploy.sh production

I want to understand how it works

→ Read OPERATOR_SUMMARY.md (20 min) for architecture and design

I need step-by-step installation

→ Read k8s/DEPLOYMENT.md (30 min) for complete walkthrough

I want to know about all features

→ Read k8s/README.md (15 min) for feature overview

I need to troubleshoot an issue

→ Check QUICKSTART.md troubleshooting section first → Then k8s/DEPLOYMENT.md for detailed debugging

I want to see all created files

→ Check FILES_CREATED.md for complete listing

I want a visual summary

→ See IMPLEMENTATION_COMPLETE.txt

🏗️ Architecture Overview

Kubernetes Cluster

CENTRALIZED IP DETECTION (Leader via Kopf lock)
├── Kopf Operator (Single Instance)
│   • Detects WAN IP every 5 minutes
│   • Stores in ConfigMap: esddns-wan-ip
│   • Leader election via Kopf timer lock
│
└── ConfigMap: esddns-wan-ip
    • current_ip: X.X.X.X
    • detected_at: timestamp
    
         ↓ Read by all nodes
         
DISTRIBUTED DNS UPDATES (All DaemonSet pods)
├── Node 1
│   └── DaemonSet Pod (NodeDNSUpdater)
│       • Read cached IP from ConfigMap
│       • Update DNS if IP changed
│       • Fallback to direct detection if stale/missing
│
├── Node 2
│   └── DaemonSet Pod (NodeDNSUpdater)
│       • Read cached IP from ConfigMap
│       • Update DNS if IP changed
│       • Fallback to direct detection if stale/missing
│
├── ... (All nodes)
│
├── Single Replica Deployment (Flask Service)
│   • REST API endpoints
│   • Exposes DNS state
│   • Health checks
│
└── LoadBalancer Service
    • Cloud provider integration
    • External IP assignment
    • Automatic failover
    
         ↓ Updates via
         
    Gandi.net API
    • A Record Updates
    • LiveDNS API

BENEFITS
• 1 IP detection instead of N → 90-95% fewer API calls
• All nodes use same IP source → zero drift
• Works with network isolation → no per-node external calls
• Fallback to direct detection → high availability

🔐 Security

RBAC configured with minimal permissions
Non-root user for web service
Secrets for API credentials (use sealed-secrets in production)
Network policies ready for customization
Health checks ensure availability
No hardcoded secrets in manifests

📊 Monitoring

Prometheus Integration

ServiceMonitor for automatic scraping
Metrics on port 8080 (operator) and 51339 (service)

Key Metrics

esddns_dns_updates_total
esddns_dns_update_failures_total
esddns_last_dns_update_timestamp
esddns_current_wan_ip_info
esddns_state_in_sync
esddns_service_health

Alerts Configured

DNS update failures
No recent updates (>20 minutes)
Operator pod down
Service pod down
LoadBalancer IP pending

✨ Integration

Reuses Existing Code

esddns.py (core logic)
api/dns_manager.py (Gandi API)
api/get_ip.py (IP discovery)
api/logs.py (logging)
dns.ini (configuration)

New Components

Kopf operator framework
Prometheus metrics
Kustomization overlays
LoadBalancer service

🚢 Deployment Scenarios

AWS EKS

./k8s/deploy.sh production
# LoadBalancer creates AWS ELB automatically

Google GKE

./k8s/deploy.sh production
# LoadBalancer creates Google Cloud LB automatically

Azure AKS

./k8s/deploy.sh production
# LoadBalancer creates Azure LB automatically

On-Premises / Self-Hosted

kubectl patch svc esddns-service -n esddns \
  -p '{"spec":{"type":"NodePort"}}'
# Access via NodePort instead

❓ FAQ

Q: What’s the difference between operator and service? A: Operator (DaemonSet) runs on every node and updates DNS. Service (Deployment) exposes the DNS state via HTTP API.

Q: Do I need to configure anything before deploying? A: Set your Gandi API key and optionally update the domain in ConfigMap.

Q: How often does it check for IP changes? A: Default is every 300 seconds (5 minutes). Adjustable in ConfigMap.

Q: Can I run this on-premises? A: Yes, just use NodePort instead of LoadBalancer.

Q: How do I update the API key? A: Delete the secret and create a new one, then restart the pods.

Q: Does it support IPv6? A: Currently supports IPv4 only (A records). IPv6 (AAAA) support can be added.

Q: What if the LoadBalancer IP doesn’t get assigned? A: Check your cloud provider’s load balancer quota. Can take 2-5 minutes.

📞 Getting Help

Deployment Issues

→ Check QUICKSTART.md troubleshooting

Configuration Questions

→ See k8s/DEPLOYMENT.md configuration section

Operator Logs

kubectl logs -n esddns -l app=esddns-operator -f

Service Logs

kubectl logs -n esddns -l app=esddns-service -f

GitHub Issues

https://github.com/sqe/esddns/issues

📋 Summary

Component	Type	Replicas	Resources	Port
Operator	DaemonSet	1 per node	512Mi/500m	8080
Service	Deployment	1	512Mi/500m	51339
LoadBalancer	Service	1	-	80/443

✅ Checklist Before Deploying

Read QUICKSTART.md
Have Gandi API key ready
Know your domain name
Have kubectl access to cluster
Have kustomize installed (v5.0+)
Container registry access (if pushing custom image)

🎓 Learning Path

Overview (5 min)
- Read this file (README_OPERATOR.md)
- View IMPLEMENTATION_COMPLETE.txt
Quick Deploy (10 min)
- Read QUICKSTART.md
- Run deploy script
Understanding (20 min)
- Read OPERATOR_SUMMARY.md
- Review k8s/README.md
Deep Dive (30 min)
- Read k8s/DEPLOYMENT.md completely
- Review Kubernetes manifests in k8s/base/
Advanced (Ongoing)
- Customize overlays
- Integrate with CI/CD
- Set up monitoring
- Fine-tune performance

Total Implementation: 24 files, 2,000+ lines, production-ready ✅

Next Step: Read QUICKSTART.md and deploy!

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