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Eddie Gulay @eddiegulay

Dockerfile Instructions For Efficient Image Creation

Master Dockerfile instructions: FROM, WORKDIR, COPY, RUN, CMD & more. Learn how to build efficient images with best practices for caching, layering and multi-stage builds.

The Dockerfile is at the heart of Docker image creation. It is a text file that contains a series of instructions on how to build a Docker image, similar to a recipe. Each instruction in a Dockerfile creates a layer in the final image, which makes Docker images lightweight, efficient, and reusable.

  
  
  Key Dockerfile Instructions


FROM

The FROM instruction specifies the base image to use for the subsequent instructions. Every Dockerfile must begin with a FROM instruction.
Example:

 FROM python:3.9-slim



Explanation: This starts from a minimal Python 3.9 image. The base image can be a...