Pod Resource Calculator

A Kubernetes resource spreadsheet calculator tool that generates Excel reports of pod resource requests and limits across your cluster.

Features

• Kubernetes Integration: Connects to any Kubernetes cluster (in-cluster or via kubeconfig)
• Resource Analysis: Extracts CPU and memory requests/limits for all containers
• Excel Output: Generates professional Excel spreadsheets with formulas and formatting
• Namespace Filtering: Support for specific namespaces or cluster-wide analysis
• Multi-platform: Builds for Linux, Windows, macOS, and FreeBSD
• Modern Go: Built with Go 1.23 and latest Kubernetes client libraries

Prerequisites

• Access to a Kubernetes cluster
• Valid kubeconfig file (for out-of-cluster usage)
• Or running inside a Kubernetes cluster with appropriate RBAC permissions

Quick Start

Build and Run

cd src
make build
../PodResourceCalculator -verbose

Usage Examples

# Analyze all namespaces
./PodResourceCalculator -verbose

# Analyze specific namespace
./PodResourceCalculator -namespace kube-system -verbose

# Custom output filename
./PodResourceCalculator -output my-resources.xlsx

# Use specific kubeconfig
./PodResourceCalculator -kubeconfig ~/.kube/config-prod

Command Line Options

Flag	Description	Default
-namespace	Kubernetes namespace to analyze	All namespaces
-kubeconfig	Path to kubeconfig file	~/.kube/config
-output	Output Excel filename	resource_YYYY-MM-DD.xlsx
-verbose	Enable verbose logging	false

Excel Output

The generated Excel file contains six comprehensive sheets:

Resources Sheet (Detailed Container Data)

• Namespace: Pod namespace
• Pod: Pod name
• Pod Age: Time since pod creation (e.g., "5h30m15s")
• Restart Count: Total container restarts in pod
• Last Restart: Time since last container termination (e.g., "2h ago")
• Node: Host node IP
• Container: Container name
• Status: Pod status (Running, Pending, etc.)
• QoS Class: Quality of Service class (Guaranteed, Burstable, BestEffort)
• Request CPU (m): CPU requests in millicores
• Request CPU: CPU requests (canonical format)
• Request Memory (Mi): Memory requests in mebibytes (integer)
• Request Memory: Memory requests (canonical format)
• Limit CPU (m): CPU limits in millicores
• Limit CPU: CPU limits (canonical format)
• Limit Memory (Mi): Memory limits in mebibytes (integer)
• Limit Memory: Memory limits (canonical format)
• Request Storage (Gi): Ephemeral-storage requests in gibibytes
• Request Storage: Ephemeral-storage requests (canonical format)
• Limit Storage (Gi): Ephemeral-storage limits in gibibytes
• Limit Storage: Ephemeral-storage limits (canonical format)
• Request GPU: GPU requests (nvidia.com/gpu)
• Request GPU (str): GPU requests (canonical format)
• Limit GPU: GPU limits (nvidia.com/gpu)
• Limit GPU (str): GPU limits (canonical format)
• CPU Efficiency %: Request/Limit ratio for CPU
• Memory Efficiency %: Request/Limit ratio for Memory

Summary Sheet (Namespace Aggregation)

• Namespace-level totals: Resource aggregation per namespace
• CPU in cores: Request and limit CPU converted to cores
• Memory in Mi: Request and limit memory converted to mebibytes (Mi)
• Alphabetical sorting: Namespaces sorted for easy navigation
• Clean data table: Optimized for analysis and reference

Nodes Sheet (Node Utilization)

• Node IP: Host node identifier
• Pod Count: Number of pods per node
• Capacity CPU: Total CPU capacity per node
• Allocatable CPU: Node allocatable CPU (capacity minus system reservations)
• Request CPU: Total CPU requests per node
• Limit CPU: Total CPU limits per node
• CPU Utilization %: Percentage of allocatable CPU requested (right-aligned)
• Capacity Memory (Mi): Total memory capacity per node (integer)
• Allocatable Memory (Mi): Node allocatable memory (capacity minus system reservations, integer)
• Request Memory (Mi): Total memory requests per node (integer)
• Limit Memory (Mi): Total memory limits per node (integer)
• Memory Utilization %: Percentage of allocatable memory requested (right-aligned)
• Capacity planning: Understand node resource distribution and utilization
• Alphabetical sorting: Nodes sorted by IP address

Chart Sheet (Visual Analytics)

• Dynamic bar chart: Resource requirements by namespace
• Scalable dimensions: Chart size adapts to data volume (1.5x scaling)
• Top legend: Professional layout with legend at top
• Four data series: Request CPU, Limit CPU, Request Memory, Limit Memory
• Cross-sheet references: Automatically updates with data changes

Insights Sheet (Data Science Analytics)

• Resource efficiency analysis: Cluster-wide efficiency metrics
• Node distribution analysis: Pod distribution and load balancing
• Optimization recommendations: Actionable insights for resource optimization

Pod Security Sheet (Security Standards)

• Namespace security levels: Pod Security Standards (PSS) configuration per namespace
• Three modes tracked: Enforce, Audit, and Warn levels
• Version information: PSS version for each mode
• Cluster defaults: Note about unset labels using cluster default configuration
• Security levels: privileged, baseline, or restricted
• Compliance overview: Quick view of cluster security posture

Features

• Auto-filter: Easy sorting and filtering on Resources sheet
• Conditional formatting: Color-coded efficiency percentages
  • Red (≥80%): High resource utilization
  • Yellow (60-79%): Medium utilization
  • Teal (40-59%): Low utilization
  • Light Green (<40%): Very low utilization
• Progress indicators: Shows processing progress for large clusters
• Pod status filtering: Only includes Running and Pending pods
• Missing resource handling: Shows "Not Set" for containers without limits/requests
• Summary formulas: Automatic totals in Resources sheet row 1
  • D1: Total CPU requests (cores, rounded to 2 decimals)
  • F1: Total memory requests (Mi, rounded to 2 decimals)
  • H1: Total CPU limits (cores, rounded to 2 decimals)
  • J1: Total memory limits (Mi, rounded to 2 decimals)
• Freeze panes: Header rows stay visible when scrolling
• Optimized column widths: Properly sized for content readability
• Professional charts: Dedicated chart sheet with dynamic sizing
• Alphabetical sorting: Consistent ordering across all sheets
• Multi-dimensional analysis: Container, namespace, and node-level views

Build System

Available Make Targets

make help          # Show all available targets
make build         # Build for current platform
make build-all     # Build for all platforms
make test          # Run tests
make clean         # Clean build artifacts
make deps          # Download and tidy dependencies
make run           # Build and run with verbose output

Multi-platform Builds

make build-all

Generates binaries for:

• Linux (amd64)
• Windows (amd64)
• macOS (amd64)
• FreeBSD (amd64)

Development

Project Structure

PodResourceCalculator/
├── src/
│   ├── main.go           # Main application
│   ├── Makefile          # Build automation
│   ├── go.mod            # Go module definition
│   └── go.sum            # Dependency checksums
├── .vscode/
│   └── settings.json     # VSCode configuration
├── .editorconfig         # Editor configuration
├── .gitignore           # Git ignore rules
└── README.md            # This file

Dependencies

• Kubernetes Client: k8s.io/client-go v0.31.2
• Excel Generation: github.com/xuri/excelize/v2 v2.9.1
• Logging: github.com/sirupsen/logrus v1.9.3

RBAC Requirements

For in-cluster usage, ensure the service account has appropriate permissions:

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: pod-resource-reader
rules:
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["get", "list"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: pod-resource-reader-binding
subjects:
- kind: ServiceAccount
  name: your-service-account
  namespace: your-namespace
roleRef:
  kind: ClusterRole
  name: pod-resource-reader
  apiGroup: rbac.authorization.k8s.io

Examples

Basic Usage

# Generate report for all namespaces
./PodResourceCalculator

# Generate report with custom filename
./PodResourceCalculator -output cluster-resources-$(date +%Y%m%d).xlsx

Integration with kubectl

# Check if you have access to pods first
kubectl auth can-i list pods --all-namespaces

# Run the calculator
./PodResourceCalculator -verbose

Docker Usage

# Build in container
docker run --rm -v $(PWD):/workspace -w /workspace/src golang:1.23-alpine \
  sh -c "go build -o ../PodResourceCalculator ."

# Run with mounted kubeconfig
docker run --rm -v $(PWD):/workspace -v ~/.kube:/root/.kube \
  -w /workspace your-image ./PodResourceCalculator

Troubleshooting

Common Issues

"Failed to connect to Kubernetes"

• Verify kubeconfig is valid: kubectl cluster-info
• Check network connectivity to cluster
• Ensure proper RBAC permissions

"Failed to list pods"

• Check RBAC permissions for pod listing
• Verify namespace exists (if specified)
• Try with -verbose flag for detailed logging

Empty Excel file

• No pods found in specified namespace
• All pods may lack resource specifications
• Check with kubectl get pods -n <namespace>

License

This project is open source. See the original blog post for more details: https://medium.com/@zhimin.wen/pod-resource-spreadsheet-calculator-22fc5c6173b9

Since pull requests were never answered, this repo is no longer linked to the original or any other fork