Generated result
Checks
Build command
Run command
Application setup
Dependencies and commands
Additional RUN commands
Build arguments and environment variables
Build arguments
Environment variables
Ports, volumes, labels, and runtime
Security and user
Health check
CMD and ENTRYPOINT
Multi-stage build
.dockerignore generator
Compose companion
Import and advanced instructions
Formula used
The generator assembles instructions from selected options. The score starts at 100 points. Warnings subtract points based on security, caching, image size, secrets, health checks, and production-readiness indicators.
How to use this calculator
Select an application preset first. Adjust the base image and working directory. Add dependency and build commands next. Configure ports and runtime behavior. Enable security options for production workloads. Add a health check when useful. Use multi-stage builds for compiled applications. Review warnings beside the generated result. Copy or download each generated file. Test the image before deployment. Never place real secrets inside generated environment variables.
Example configurations
| Application | Base image | Port | Typical command |
|---|---|---|---|
| Node.js | node:22-alpine | 3000 | node server.js |
| Django | python:3.13-slim | 8000 | gunicorn project.wsgi:application |
| Spring Boot | eclipse-temurin:21-jre-alpine | 8080 | java -jar app.jar |
| Static site | nginx:1.27-alpine | 80 | nginx default |
Dockerfile generation guidance
Dockerfiles describe how container images are assembled and started. A good file remains readable while minimizing unnecessary image layers. Small runtime images often reduce transfer sizes and attack surfaces. Dependency manifests should usually copy before the main source. That ordering lets unchanged dependencies reuse cached build layers. Multi-stage builds separate compilation tools from final runtime files. They work well for Go Java frontend and compiled workloads. Non-root users reduce container privileges when applications support them. Health checks can expose failing application processes to orchestration systems. Build secrets should use temporary secret mounts whenever possible. Avoid embedding passwords tokens or private keys into image layers.
Application presets provide useful starting points rather than strict requirements. Base image versions should match your application and support policy. Alpine images are small but can differ from glibc environments. Slim images often provide easier compatibility for general workloads. Package caches should be removed when they provide no runtime value. Build cache mounts can still accelerate repeat package installations. The generated run command maps configured ports and volume locations. Compose output gives a convenient local multi-container starting configuration. Always inspect custom instructions before running a generated container build.
Validation warnings highlight common configuration risks and optimization opportunities. A perfect score does not guarantee a secure deployment. Runtime permissions networks secrets storage and host security still matter. Production images should contain only files required by the application. Keep test tools compilers and package managers out when practical. Pinning versions improves reproducibility but requires regular security update maintenance. Avoid untrusted base images and review image sources carefully. Use automated image scanning in important deployment pipelines. Rebuild images regularly to receive operating system security patches. Test health checks because aggressive timings can create false failures.
This generator also creates a matching dockerignore file automatically. Ignored files stay outside the Docker build context when selected. Excluding local dependencies can make builds much faster. Environment files should usually remain outside the image context. Generated Compose settings are intended as editable development-friendly defaults. Production orchestration may require different networking storage and secret systems. Imported Dockerfiles only populate basic fields where patterns are recognizable. Complex files may need manual review after importing. Downloaded files can be edited normally before use. Review every generated command before using it in production. Careful testing keeps container behavior predictable across deployment environments.