CLAUDE.md - Python IPAM Project

Claude Code-specific configuration and standards for the Python IPAM project.

Documentation Standards

IMPORTANT LANGUAGE REQUIREMENT:

ALL documentation MUST be written in English
This includes: README.md, API.md, FEATURES.md, REFACTORING.md, CLAUDE.md, code comments, commit messages
German or other languages are NOT permitted in documentation

DOCUMENTATION UPDATE POLICY:

Every code change MUST be evaluated for documentation impact
Before committing ANY change, ask: "Does this require documentation updates?"
Documentation files to check:
- README.md - User-facing documentation, setup instructions
- API.md - REST API endpoint documentation
- FEATURES.md - Feature tracking and roadmap
- REFACTORING.md - Architecture and refactoring notes
- CLAUDE.md - This file, project standards
Documentation updates should be committed together with code changes
Never commit code without updating related documentation

Project Overview

Python IPAM is a modern IP Address Management (IPAM) system based on:

Flask 3.0 (Python Web Framework)
SQLite/SQLAlchemy (Database)
Bootstrap 5 + DataTables (Frontend)
pytest (Testing Framework)
Docker (Containerization)

Code Style Rules

Python (Google Style Guide)

Formatter: Black with 80 character line length

black . --line-length 80

Linting: Pylint with Google configuration

pylint --rcfile=https://google.github.io/styleguide/pylintrc app.py tests/

Naming Conventions:

Modules/Packages: lowercase_with_underscores
Classes: CapWords (e.g., NetworkForm, HostModel)
Functions/Variables: lowercase_with_underscores
Constants: CAPS_WITH_UNDERSCORES
Private: _leading_underscore

Import Order (separated by blank lines):

from __future__ import annotations

import os
import ipaddress

from flask import Flask, render_template
from flask_sqlalchemy import SQLAlchemy

from ipam import db, Network, Host

Dockerfile (Hadolint Standard)

Follow security best practices:

FROM python:3.11-slim

# Security: Non-root user
RUN useradd -r -s /bin/false ipam
USER ipam

# Layer optimization
RUN apt-get update && \
    apt-get install -y --no-install-recommends gcc && \
    apt-get clean && \
    rm -rf /var/lib/apt/lists/*

# JSON notation for CMD
CMD ["gunicorn", "--bind", "0.0.0.0:5000", "app:app"]

Git Commits (Angular Convention)

Format:

<type>(<scope>): <short summary>

<body>

<footer>

Types for this project:

feat: New IPAM features (Host/Network management)
fix: Bug fixes in web UI or API
test: Unit tests for models/routes/forms
docker: Container configuration
docs: README or API documentation

Examples:

feat(networks): add VLAN ID support
fix(hosts): resolve auto-detection for overlapping subnets
test(models): add network cascade delete tests
docker: optimize layer caching in Dockerfile
docs: update pyenv setup instructions

IMPORTANT: Do not use AI signatures in commits!

Shell/Bash

For test scripts and setup automation:

#!/bin/bash

# Functions
function setup_venv() {
  local python_version="$1"
  echo "Setting up Python ${python_version}..."
}

# Prefer [[ ]]
if [[ -d "venv" ]]; then
  source venv/bin/activate
fi

# Quote variables
echo "PATH: ${PATH}"

Project-Specific Standards

Testing

Test Structure:

tests/
├── conftest.py              # Pytest fixtures (Application Factory)
├── test_models.py           # SQLAlchemy Model Tests
├── test_routes.py           # Flask Route Tests
├── test_forms.py            # WTForms Validation Tests
├── test_database.py         # Database initialization tests
├── test_export_import.py    # Export/Import plugin tests
└── test_crud_operations.py  # CRUD operation tests

Test Commands:

# All tests
pytest -v

# With coverage
pytest --cov=ipam --cov-report=html

# Specific tests
pytest tests/test_models.py::TestNetworkModel::test_network_properties

# Database tests
pytest tests/test_database.py -v

Database Models

SQLAlchemy models in ipam/models.py:

from ipam.extensions import db

class Network(db.Model):
    __tablename__ = 'networks'  # Explicit table names

    # Primary Keys as first column
    id = db.Column(db.Integer, primary_key=True)

    # Relationships with cascade definitions
    hosts = db.relationship('Host', backref='network_ref',
                           cascade='all, delete-orphan')

    # Properties for calculated values
    @property
    def total_hosts(self):
        return len(list(ipaddress.IPv4Network(
            f"{self.network}/{self.cidr}", strict=False
        ).hosts()))

Flask Application Structure

Application Factory Pattern in ipam/__init__.py:

from ipam.extensions import db
from ipam.config import config

def create_app(config_name='default'):
    app = Flask(__name__)
    app.config.from_object(config[config_name])

    db.init_app(app)

    from ipam.web import web_bp
    from ipam.api import api_bp

    app.register_blueprint(web_bp)
    app.register_blueprint(api_bp)

    return app

Flask Routes

Web Routes in ipam/web/routes.py:

from ipam.web import web_bp
from ipam.extensions import db
from ipam.models import Network, Host

@web_bp.route('/')
def index():
    """Dashboard."""
    networks = Network.query.all()
    return render_template('index.html', networks=networks)

API Routes in ipam/api/networks.py:

from flask_restx import Namespace, Resource
from ipam.extensions import db
from ipam.models import Network

api = Namespace('networks', description='Network operations')

@api.route('/')
class NetworkList(Resource):
    def get(self):
        """List all networks."""
        networks = Network.query.all()
        return {'data': [network.to_dict() for network in networks]}

Templates

HTML/Jinja2 template standards:

Bootstrap 5 CSS classes
Responsive design
DataTables for tables
Bootstrap Icons (bi-*)

Environment & Tools

Local Development

pyenv Setup:

pyenv install 3.13
pyenv local 3.13
python -m venv venv
source venv/bin/activate
pip install -r requirements.txt

Database Initialization:

# Create database (on first start)
python3 -c "from ipam import create_app; from ipam.extensions import db; app = create_app(); app.app_context().push(); db.create_all()"

Development Server:

python app.py  # Flask dev server on :5000

# Available URLs:
# - Web Interface: http://localhost:5000
# - REST API: http://localhost:5000/api/v1
# - Swagger UI: http://localhost:5000/api/v1/docs

Docker Development

Development Container:

docker-compose --profile dev up

Production Container:

docker-compose up -d

Quality Assurance

Linting/Formatting (local):

# Python Code
black . --line-length 80
pylint app.py tests/

# Dockerfile
hadolint Dockerfile

# Shell Scripts
shellcheck run_tests.sh

Testing:

./run_tests.sh  # Complete test suite with coverage
make test       # Makefile target

API Documentation

REST API Base URL: /api/v1 Swagger UI: http://localhost:5000/api/v1/docs

Main Endpoints:

Networks:

GET /api/v1/networks - List all networks (with filtering/pagination)
POST /api/v1/networks - Create network
GET /api/v1/networks/{id} - Get network
PUT /api/v1/networks/{id} - Update network
DELETE /api/v1/networks/{id} - Delete network

Hosts:

GET /api/v1/hosts - List all hosts (with filtering/pagination)
POST /api/v1/hosts - Create host
GET /api/v1/hosts/{id} - Get host
PUT /api/v1/hosts/{id} - Update host
DELETE /api/v1/hosts/{id} - Delete host

IP Management:

GET /api/v1/ip/networks/{id}/next-ip - Get next free IP
GET /api/v1/ip/networks/{id}/available-ips - List all free IPs
GET /api/v1/ip/{ip_address} - Query IP status

Response Format:

{
  "data": [...],
  "pagination": {
    "page": 1,
    "per_page": 50,
    "total_items": 100,
    "total_pages": 2
  }
}

Complete documentation: API.md

Deployment

Container Images

Production Images (Chainguard distroless):

Registry: ghcr.io/tuxpeople/python-ipam
Base: cgr.dev/chainguard/python:latest (distroless)
Security: 0 CRITICAL/HIGH vulnerabilities (Trivy scanned)
Size: ~50-100MB (multi-stage build)
User: nonroot (UID 65532)
Python: 3.13

Tags:

latest - Always points to latest stable release
1.0.0 - Specific patch version
1.0 - Minor version (updates with new patches)
1 - Major version (updates with new minors/patches)
main-<sha> - Git commit SHA for main branch builds

Multi-stage Build:

# Stage 1: Build dependencies in -dev image
FROM cgr.dev/chainguard/python:latest-dev AS build
RUN python -m venv /home/nonroot/venv && \
    /home/nonroot/venv/bin/pip install --upgrade 'pip<25.2' setuptools wheel

# Stage 2: Install Python packages
FROM build AS build-venv
COPY requirements.txt /tmp/requirements.txt
RUN /home/nonroot/venv/bin/pip install -r /tmp/requirements.txt

# Stage 3: Minimal runtime image (distroless)
FROM cgr.dev/chainguard/python:latest
COPY --from=build-venv /home/nonroot/venv /home/nonroot/venv
ENV PATH="/home/nonroot/venv/bin:$PATH"

Kubernetes (if used):

# Follow Kubernetes best practices
metadata:
  labels:
    app.kubernetes.io/name: python-ipam
    app.kubernetes.io/version: "1.0.0"
    app.kubernetes.io/component: backend
spec:
  securityContext:
    runAsNonRoot: true
    runAsUser: 65532
    fsGroup: 65532

Troubleshooting

Common Issues:

SQLite Lock Issues:

# Use context manager
with app.app_context():
    db.session.commit()

pyenv Python not found:

pyenv rehash
which python  # Should show pyenv version

Docker Build Failures:

docker system prune  # Cleanup
docker build --no-cache .

Maintenance

Dependencies Update:

pip list --outdated
pip install -U package_name
pip freeze > requirements.txt

Database Migrations (on schema changes):

# In Python Console
from ipam import create_app
from ipam.extensions import db

app = create_app()
with app.app_context():
    db.drop_all()  # Caution in production!
    db.create_all()

Database Initialization (Command line):

python3 -c "from ipam import create_app; from ipam.extensions import db; app = create_app(); app.app_context().push(); db.create_all()"

Release Process

Semantic Versioning

This project follows Semantic Versioning 2.0.0:

Version Format: MAJOR.MINOR.PATCH

MAJOR: Breaking changes (API changes, database schema changes)
MINOR: New features (backwards compatible)
PATCH: Bug fixes (backwards compatible)

Examples:

v1.0.0 - First production release
v1.1.0 - New features (e.g., subnet calculator)
v1.1.1 - Bug fixes
v2.0.0 - Breaking changes (e.g., database schema migration)

Creating a Release

IMPORTANT: Every version MUST have:

Git tag (annotated)
GitHub Release with changelog
Docker image published to GHCR

Release Checklist:

Update Version (if not already done):

# Update version in relevant files if needed
# (Currently no __version__ file, but could be added)

Run Full Test Suite:

pytest -v
black . --check --line-length 80
hadolint Dockerfile

Update Documentation:
- Check README.md, API.md, FEATURES.md for accuracy
- Update CLAUDE.md changelog (see below)
- Ensure all recent changes are documented

Create Git Tag:

# Create annotated tag with version (must start with 'v' for CI/CD)
git tag -a v1.0.0 -m "v1.0.0"

# Push tag to GitHub (triggers Docker build)
git push origin v1.0.0

Create GitHub Release:

# Create release with changelog (title should be version only)
gh release create v1.0.0 \
  --title "v1.0.0" \
  --notes-file /tmp/release-notes.md

Release Notes Template (/tmp/release-notes.md):

# Python IPAM v1.0.0

Brief description of the release.

## 🚀 Features
- New feature 1
- New feature 2

## 🐛 Bug Fixes
- Fix for issue #123

## 🔒 Security
- Security improvements

## 📦 Container Image
\`\`\`bash
docker pull ghcr.io/tuxpeople/python-ipam:1.0.0
docker pull ghcr.io/tuxpeople/python-ipam:1.0
docker pull ghcr.io/tuxpeople/python-ipam:1
docker pull ghcr.io/tuxpeople/python-ipam:latest
\`\`\`

## 🔄 Migration Notes
- Breaking changes (if any)
- Upgrade instructions

## 📝 Full Changelog
https://github.com/tuxpeople/python-ipam/compare/v0.9.0...v1.0.0

Verify Docker Image:

# CI/CD automatically builds and pushes to GHCR on tag push
# Verify all tags are available (wait ~5 minutes for build)
docker pull ghcr.io/tuxpeople/python-ipam:1.0.0
docker pull ghcr.io/tuxpeople/python-ipam:1.0
docker pull ghcr.io/tuxpeople/python-ipam:1
docker pull ghcr.io/tuxpeople/python-ipam:latest

Update CLAUDE.md Changelog (after release):

### 2025-10-03 - v1.0.0
- ✅ First production release
- ✅ Chainguard distroless migration (0 vulnerabilities)
- ✅ Complete CI/CD pipeline

Hotfix Release Process

For urgent bug fixes:

Create branch from tag:
```
git checkout -b hotfix/v1.0.1 v1.0.0
```

Apply fix and test:

# Make changes
pytest -v
git commit -m "fix: critical bug in network calculation"

Tag and release:

git tag -a v1.0.1 -m "v1.0.1"
git push origin v1.0.1
gh release create v1.0.1 --title "v1.0.1" --notes "Critical bug fix"

Merge back to main:

git checkout main
git merge hotfix/v1.0.1
git push origin main

CI/CD Integration

The GitHub Actions workflow automatically:

Builds Docker image on tag push (tags starting with v)
Generates SBOM with Anchore
Scans with Trivy (fails on CRITICAL/HIGH)
Pushes to GHCR with multiple version tags
Creates tags: 1.0.0, 1.0, 1, latest (from Git tag v1.0.0)

Last Update: 2025-10-03 Maintainer: Python IPAM Team

Changelog

2025-10-03 - v1.0.0 Production Release

✅ Security Hardening: Migrated to Chainguard distroless Python images
✅ Security Achievement: Reduced vulnerabilities from 275+ to 0 (100% reduction)
✅ Container Optimization: Multi-stage build, image size reduced to ~50-100MB
✅ CI/CD Pipeline: Automated testing, security scanning (Trivy), SBOM generation
✅ GitHub Infrastructure: Issue templates, project roadmap, automated workflows
✅ Extensible Export/Import: Plugin-based architecture (IPAM-004)
✅ Documentation: Complete English documentation, GitHub Pages deployment
✅ Test Suite: 96 tests passing, all SQLAlchemy 2.0 deprecations fixed
✅ Release Process: Established semantic versioning with Git tags and GitHub releases
✅ REST API: Flask-RESTX with Swagger UI at /api/v1/docs
✅ Application Factory Pattern: Modular Blueprint structure
✅ Python 3.13: Upgraded to latest Python version

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CLAUDE.md - Python IPAM Project

Documentation Standards

Project Overview

Code Style Rules

Python (Google Style Guide)

Dockerfile (Hadolint Standard)

Git Commits (Angular Convention)

Shell/Bash

Project-Specific Standards

Testing

Database Models

Flask Application Structure

Flask Routes

Templates

Environment & Tools

Local Development

Docker Development

Quality Assurance

API Documentation

Deployment

Container Images

Troubleshooting

Maintenance

Release Process

Semantic Versioning

Creating a Release

Hotfix Release Process

CI/CD Integration

Changelog

2025-10-03 - v1.0.0 Production Release

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CLAUDE.md

Latest commit

History

CLAUDE.md

File metadata and controls

CLAUDE.md - Python IPAM Project

Documentation Standards

Project Overview

Code Style Rules

Python (Google Style Guide)

Dockerfile (Hadolint Standard)

Git Commits (Angular Convention)

Shell/Bash

Project-Specific Standards

Testing

Database Models

Flask Application Structure

Flask Routes

Templates

Environment & Tools

Local Development

Docker Development

Quality Assurance

API Documentation

Deployment

Container Images

Troubleshooting

Maintenance

Release Process

Semantic Versioning

Creating a Release

Hotfix Release Process

CI/CD Integration

Changelog

2025-10-03 - v1.0.0 Production Release