Dockerfile ARG ↔ ENV Converter
ARG defines build-time variables; ENV defines runtime variables. Common pattern: declare both so you can override at build OR runtime. This converter takes a list of ARG/ENV directives and converts between forms.
ARG vs ENV quick reference
| ARG | Build-time only. Available during docker build. NOT in the final image\'s environment. |
|---|---|
| ENV | Both build-time AND runtime. Set in the image, available to processes inside the container. |
| Common pattern | ARG VERSION=1.0ENV VERSION=$VERSIONLets you override at build ( --build-arg VERSION=2.0) and the value persists at runtime. |
| Secrets | Never use ENV for secrets (persisted in image layers). Use Docker BuildKit secrets or runtime env-files. |
How to use the Dockerfile ARG ↔ ENV Converter
Paste your existing ARG or ENV lines. Pick what to convert to. The output handles defaults (ARG =value) correctly.