HPA Monitor

A Kubernetes HPA (Horizontal Pod Autoscaler) monitoring application with real-time dashboard and WebSocket updates.

The dashboard provides real-time monitoring of HPA resources with tolerance calculations, showing current vs desired replicas, scaling status, and recent events.

Features

• Real-time HPA monitoring with tolerance calculations using native Kubernetes API
• Multi-metric support (CPU, memory, custom metrics)
• WebSocket-based live updates
• Kubernetes events tracking
• Web dashboard interface

Quick Start

Prerequisites

• Go 1.24+
• Docker
• Kubernetes cluster (or KWOK for testing)
• Helm 3.x

Development

# Run locally
make run

# Build binary
make build

# Run tests
make test

Deployment

Helm Installation

HPA Monitor provides a Helm chart for easy deployment to Kubernetes clusters with RBAC configuration, customizable values, and follows Kubernetes best practices.

# Install from a specific values file
helm upgrade --install hpa-monitor ./charts/hpa-monitor \
  --namespace hpa-monitor \
  --create-namespace \
  --values ./charts/hpa-monitor/values.yaml

Quick Deployment

# Deploy to KWOK cluster (recommended for testing)
make deploy-kwok

# Or deploy to existing cluster
make deploy

Access

For local development, run go run cmd/hpa-monitor/main.go and access the dashboard at http://localhost:8080.

For Kubernetes deployments, use port-forwarding to access the dashboard:

# Port-forward to access the dashboard
kubectl port-forward svc/hpa-monitor 8080:8080 -n hpa-monitor
# Then access at http://localhost:8080

Configuration

Environment variables:

• PORT - Server port (default: 8080)
• WEBSOCKET_INTERVAL - Update interval in seconds (default: 5)
• TOLERANCE - HPA tolerance percentage, 0.1 means 10% (default: 0.1) - Kubernetes HPA Tolerance
• LOG_LEVEL - Log level: debug, info, warn, error, fatal, panic (default: info)

Commands

make run              # Run locally
make build            # Build binary
make test             # Run tests
make docker-build     # Build container
make deploy           # Deploy to cluster
make check-hpa        # Check HPA status
make logs             # View logs
make clean            # Clean artifacts

Architecture

HPA Monitor is built with a lightweight Go backend that directly interfaces with the Kubernetes API to monitor HPA resources and stream real-time data to a responsive web dashboard.

• Backend: Go with Gin framework for HTTP server and WebSocket-based real-time HPA data streaming
• Frontend: HTML/JavaScript with WebSocket
• Deployment: Helm chart with RBAC
• Monitoring: Kubernetes client-go with custom tolerance logic