Ln 731 Docker Generator

ln-731-docker-generator

Type: L3 Worker Category: 7XX Project Bootstrap Parent: ln-730-devops-setup

Generates production-ready Docker configuration for containerized development.

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Purpose & Scope

Creates Docker infrastructure for local development and production:

• Does: Generate Dockerfiles, docker-compose, .dockerignore, nginx config
• Does NOT: Build images, start containers, manage deployments

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Inputs

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Outputs

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Workflow

Phase 1: Input Validation

Validate received configuration from coordinator:

• Check stack type is supported (frontend, backend-dotnet, backend-python)
• Verify versions are valid (Node 18+, .NET 8+, Python 3.10+)
• Confirm project directory exists

Output: Validated configuration or error

Phase 2: Template Selection

Select appropriate templates based on stack:

Phase 3: Variable Substitution

Replace template variables with detected values:

Phase 4: File Generation

Generate files from templates:

1. Check if file already exists (warn before overwrite)
2. Apply variable substitution
3. Write file to appropriate location
4. Validate syntax where possible

File Locations:

• Dockerfile.frontend -> src/​frontend/​Dockerfile
• Dockerfile.backend -> project root
• docker-compose.yml -> project root
• .dockerignore -> project root
• nginx.conf -> src/​frontend/​nginx.conf

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Supported Stacks

Frontend: React/​Vite + Nginx

Requirements:

• package.json with build script
• Vite or CRA configuration

Generated:

• Multi-stage Dockerfile (builder + nginx)
• Nginx config with SPA routing and API proxy

Backend: .NET 8/​9

Requirements:

• *.sln file in root
• *.csproj with TargetFramework

Generated:

• Multi-stage Dockerfile (SDK build + ASP.NET runtime)
• Health check endpoint configuration

Backend: Python (FastAPI/​Django)

Requirements:

• requirements.txt or pyproject.toml

Generated:

• Multi-stage Dockerfile (builder + slim runtime)
• uvicorn (FastAPI) or gunicorn (Django) entrypoint

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Security & Performance Best Practices

All generated files follow these guidelines:

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Quality Criteria

Generated files must meet:

• docker-compose config validates without errors
• All base images use specific versions (not latest)
• Non-root user configured in all Dockerfiles
• Health checks present for all services
• .dockerignore excludes all sensitive files
• No hardcoded secrets or passwords

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Critical Notes

1. Version Detection: Use detected versions from coordinator, not hardcoded defaults.
2. Idempotent: Check file existence before writing. Warn if overwriting.
3. Template-based: All generation uses templates from references/​. Do NOT hardcode file contents.
4. Security First: Every generated file must follow security best practices.

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Reference Files

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Version: 1.2.0 Last Updated: 2026-01-21