Docker
/Intermediate
Base Images
Definition
An image that has no parent image, usually an operating system like Ubuntu or Alpine. It serves as the foundational starting point for building a custom Docker Image.
Explain Like I'm New
The blank canvas you start painting on. You can't just put Python code in an empty box; it needs an operating system to run on. The Base Image provides that foundational OS.
Real World Example
Almost every Dockerfile starts with the word `FROM`. For example, `FROM node:18-alpine`. This tells Docker to download a pre-configured version of Linux that already has Node installed, and use that as the foundation to build your app upon.
Common Use Cases
- •Dockerfile creation
- •Security hardening
Interview Questions
basic
- What keyword is always used at the very top of a Dockerfile to define the Base Image?
intermediate
- What is the `scratch` base image used for?