Generate Dockerfile (Language-Aware)

Generate optimized Dockerfile and .dockerignore by detecting project language(s) and applying best practices.

Universal Docker Standards

These apply to ALL languages:

•Multi-stage builds - Separate builder and runtime stages
•Minimal runtime image - Only production dependencies
•Non-root user - Security best practice
•Entry point detection - Detect from project context
•Cache optimization - Layer ordering for fast rebuilds
•Reproducible builds - Locked dependencies

Workflow

1. Detect Project Language(s)

text

Glob: pyproject.toml, requirements.txt, package.json, go.mod, Cargo.toml, pom.xml, build.gradle, Gemfile

File Found	Language	Reference File
`pyproject.toml` or `requirements.txt`	Python	`references/python.md`
`package.json`	Node.js/React	`references/nodejs.md`
`go.mod`	Go	`references/go.md`
`Cargo.toml`	Rust	`references/rust.md`
`pom.xml` or `build.gradle`	Java	`references/java.md`

2. Single Language Project

If ONE language detected:

•Read the corresponding language reference file
•Follow its specific Dockerfile template and patterns
•Generate Dockerfile and .dockerignore

3. Multi-Language Project

If MULTIPLE languages detected (e.g., Python backend + React frontend):

•Read ALL relevant language reference files
•Present user with options via AskUserQuestion:

text

Detected languages: Python, Node.js (React)

How should we containerize?

○ Monorepo (single Dockerfile with multi-stage for both)
○ Separate containers (Dockerfile.backend, Dockerfile.frontend)
○ Backend only (Python)
○ Frontend only (Node.js/React)

•For monorepo approach, read references/multi-language.md for merging strategies
•Generate appropriate Dockerfile(s)

4. No Language Detected

If no language files found:

•Ask user via AskUserQuestion which language/framework they're using
•Proceed with selected language reference

5. Generate .dockerignore

Universal .dockerignore (language-specific additions from reference files):

dockerignore

# =============================================================================
# .dockerignore - Exclude from Docker build context
# =============================================================================

# Git
.git/
.gitignore
.gitattributes

# IDE
.idea/
.vscode/
*.swp
*.swo
*~

# Local configuration (secrets)
*.env
*.env.*
!*.env.example
local.*.yaml

# Development files
Makefile.local
Makefile.deploy
tests/
docs/
*.md
!README.md

# Docker (prevent recursive context)
Dockerfile*
docker-compose*.yml
.dockerignore

# Language-specific exclusions added below
{language_specific_ignores}

6. Report

text

Created Docker configuration:

Language(s) detected: {languages}
Reference(s) used: {reference_files}

Dockerfile
  - Multi-stage build (builder + runtime)
  - Dependency manager: {dep_manager}
  - Non-root user configured
  - Entry point: {entry_point}

.dockerignore
  - Universal exclusions + {language}-specific

Commands:
  docker build -t myapp .           # Build image
  docker run -p 8000:8000 myapp     # Run container

Next steps:
  - Use dockercraft:compose to generate docker-compose.yml

Language Reference Files

Read these based on detected language:

•references/python.md - Python with uv, multi-stage, FastAPI/Flask patterns
•references/nodejs.md - Node.js with npm/yarn/pnpm, React/Next.js patterns
•references/go.md - Go with modules, static binary builds
•references/rust.md - Rust with cargo, musl builds
•references/java.md - Java with Maven/Gradle, JRE runtime
•references/multi-language.md - Strategies for combining languages