Dockerfile Layer Analyzer

Each instruction in a Dockerfile creates a new layer. Layers are cached and reused across builds, making them a critical factor in build performance and image size. Too many layers or poorly ordered instructions can lead to slow builds, large images, and cache invalidation issues.

This analyzer checks for common issues:

• Multi-stage builds — Separate build dependencies from runtime artifacts
• Base image size — Alpine-based images vs full Debian-based
• Layer ordering — Instructions that invalidate the cache frequently
• Dependency management — npm/pip install without cache flags
• COPY strategy — Copying dependency files separately from source code
• .dockerignore — Excluding unnecessary files from build context