Kubernetes Health Check Scripts

A comprehensive collection of health check scripts for Kubernetes clusters. These scripts help diagnose issues, monitor component health, and ensure your cluster is running optimally.

🚀 Quick Start

# Clone the repository
git clone https://github.com/gstohl/kube-help.git
cd kube-help

# Make scripts executable
chmod +x *.sh

# Run all health checks
./kube-health-check.sh --all

# Run specific checks
./kube-health-check.sh cluster nodes storage

# List available checks
./kube-health-check.sh --list

📋 Prerequisites

• kubectl configured with cluster access
• jq for JSON parsing (most scripts)
• curl or wget for API checks
• Bash 4.0 or higher

🔍 Available Health Checks

Core Kubernetes Components

Script	Description	Key Features
check-k8s-health-enhanced.sh	Comprehensive cluster health	12 check categories, resource analysis, recommendations
check-node-health.sh	Node health and resources	Resource usage, pod distribution, kernel analysis
check-kubelet.sh	Kubelet component health	Node conditions, pod capacity, eviction detection
check-kube-proxy.sh	Kube-proxy analysis	Mode detection (iptables/IPVS), rule verification
check-etcd.sh	etcd cluster health	Member status, performance metrics, backup checks
check-coredns.sh	CoreDNS health	DNS resolution tests, cache analysis, metrics
check-metrics-server.sh	Metrics server status	Resource metrics, HPA functionality

Container Runtime & Versions

Script	Description	Key Features
check-containerd.sh	Container runtime health	Version compatibility, image pull errors, disk pressure
check-k8s-versions.sh	Version compatibility	Component version skew, upgrade paths, deprecations

Security & Compliance

Script	Description	Key Features
check-pod-security.sh	Pod security analysis	Security context, RBAC, compliance scoring (0-100)
check-certificates.sh	Certificate health	Expiration warnings, webhook certs, TLS validation
check-image-registry.sh	Image registry health	Pull secrets, authentication, security analysis

Storage

Script	Description	Key Features
check-storage-health.sh	Persistent storage	PV/PVC analysis, CSI drivers, capacity planning
check-longhorn.sh	Longhorn storage	Volume health, replica status, disk usage

Networking

Script	Description	Key Features
check-network-connectivity.sh	Network connectivity	Live testing, MTU analysis, policy impact
check-hostport-conflicts.sh	Host port conflicts	Port collision detection, scheduling issues
check-nginx-ingress.sh	NGINX Ingress	Controller health, configuration, SSL
check-cilium.sh	Cilium CNI	Endpoint health, network policies, IPAM
check-cilium-envoy.sh	Cilium Envoy proxy	L7 policies, proxy configuration

Observability & Operations

Script	Description	Key Features
check-loki.sh	Loki logging system	Log ingestion, storage, Promtail status
check-cert-manager.sh	cert-manager	Certificate resources, ACME status, renewal

🎯 Master Health Check Script

The kube-health-check.sh script orchestrates all health checks:

Usage

# Run all checks
./kube-health-check.sh --all

# Run specific checks
./kube-health-check.sh cluster nodes storage security

# Save output to file
./kube-health-check.sh --all --output health-report.txt

# Run checks in parallel (experimental)
./kube-health-check.sh --all --parallel

# Verbose output
./kube-health-check.sh --all --verbose

Available Check Names

• cluster - Enhanced cluster health
• nodes - Node health and resources
• storage - Persistent storage health
• network - Network connectivity test
• security - Pod security and compliance
• containerd - Container runtime health
• versions - Version compatibility
• kubelet - Kubelet health
• kube-proxy - Kube-proxy analysis
• certificates - Certificate health
• registry - Image registry health
• longhorn - Longhorn storage
• nginx - NGINX ingress controller
• loki - Loki logging system
• cilium - Cilium CNI
• cilium-envoy - Cilium Envoy proxy
• etcd - etcd key-value store
• coredns - CoreDNS
• metrics - Metrics server
• cert-manager - cert-manager
• hostport - Host port conflicts

📊 Output Format

All scripts use color-coded output for easy reading:

• 🟢 Green - Healthy/Success
• 🟡 Yellow - Warning/Attention needed
• 🔴 Red - Error/Critical issue
• 🔵 Blue - Information
• ✓ - Check passed
• ⚠ - Warning condition
• ✗ - Check failed

🔧 Examples

Basic Health Check

# Quick cluster health check
./check-k8s-health-enhanced.sh

Storage Troubleshooting

# Check all storage components
./kube-health-check.sh storage longhorn

Security Audit

# Run security-focused checks
./kube-health-check.sh security certificates registry

Network Diagnostics

# Test network connectivity
./check-network-connectivity.sh

# Check for port conflicts
./check-hostport-conflicts.sh

Version Compatibility

# Check component versions
./check-k8s-versions.sh

# Check container runtime
./check-containerd.sh

🏗️ Architecture

kube-health-check.sh (Master Script)
├── Core Checks
│   ├── check-k8s-health-enhanced.sh
│   ├── check-node-health.sh
│   └── check-kubelet.sh
├── Network Checks
│   ├── check-network-connectivity.sh
│   ├── check-kube-proxy.sh
│   └── check-nginx-ingress.sh
├── Storage Checks
│   ├── check-storage-health.sh
│   └── check-longhorn.sh
├── Security Checks
│   ├── check-pod-security.sh
│   ├── check-certificates.sh
│   └── check-image-registry.sh
└── Component Checks
    ├── check-etcd.sh
    ├── check-coredns.sh
    └── check-metrics-server.sh

🔒 Security Considerations

• Scripts use read-only kubectl commands
• No modifications are made to cluster resources
• Network tests create temporary test pods (auto-cleaned)
• Sensitive information is not logged or exposed

🐛 Troubleshooting

Script Not Found

# Ensure scripts are executable
chmod +x *.sh

kubectl Not Found

# Install kubectl or ensure it's in PATH
which kubectl

Permission Denied

# Ensure kubectl is configured with proper permissions
kubectl auth can-i get pods --all-namespaces

JSON Parsing Errors

# Install jq
# macOS: brew install jq
# Linux: apt-get install jq / yum install jq

🤝 Contributing

Feel free to submit issues and enhancement requests!

1. Fork the repository
2. Create your feature branch (git checkout -b feature/new-check)
3. Commit your changes (git commit -m 'Add new health check')
4. Push to the branch (git push origin feature/new-check)
5. Create a Pull Request

📝 License

This project is open source and available under the MIT License.

🙏 Acknowledgments

• Built with assistance from Claude
• Inspired by Kubernetes best practices and operational experience
• Community feedback and contributions

📚 Additional Resources

• Kubernetes Documentation
• kubectl Reference
• Kubernetes Troubleshooting Guide

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Note: These scripts are provided as-is for diagnostic purposes. Always review the output and recommendations in the context of your specific environment.