Dockerfile Code Syntax

Dockerfile Syntax	Explanation	Example
FROM	Specifies the base image for subsequent instructions	FROM python:3.9-alpine
LABEL	Adds metadata to an image	LABEL maintainer="John Doe <john.doe@example.com>"
RUN	Executes a command in the container	RUN pip install -r requirements.txt
CMD	Specifies the default command for the container	CMD ["python", "app.py"]
EXPOSE	Informs Docker that the container will listen on the specified network ports	EXPOSE 80
ENV	Sets environment variables	ENV FLASK_APP=app.py
COPY	Copies files from the host machine to the container	COPY . /app
ADD	Copies files from the host machine to the container, and also supports downloading files from URLs and extracting compressed archives	ADD https://example.com/archive.tar.gz /app
WORKDIR	Sets the working directory for subsequent instructions	WORKDIR /app
ARG	Defines build-time variables that can be passed to the Docker build command	ARG VERSION=1.0
VOLUME	Creates a mount point for external volumes	VOLUME /data