Docker multistage build

The Docker multistage build is a feature that can make it easier to build different Docker images based on the same base. There you can prepare an image for different purposes. And at the same time efficiently prepare images that contain everything you need while being minimalistic.

Multistage build

The principle of multistage build is that you have a common base in one configuration file and then you can create different docker images based on that. This allows you to streamline and simplify the creation of docker images.
Ted docker image for development, for testing, or minimalist for production

Example

In this link. docker multi stage example.
You can use this demonstration project to try it out, and this guide is also written based on it.

This command will execute the build image for the "base" target:

docker build --target base ./

Better, however, to name the image directly

 docker build --target base ./ -t php-web-base

Build image for target devel, which we will name php-web-dev:

docker build --target devel ./ -t php-web-dev

Build containers that are listed in the docker-compose file:

docker-compose -f docker-compose-prod.yml build

The contents of the docker-compose. The important parameter is the target parameter, which specifies what image to build and then run.

version: '3.6'
services:
  web:
      build:
        context: ./
        target: devel

If you have the container built and named, you can drop the docker image and shell console in as you would with any other docker image:

docker exec -it multistage-build_web_1 /bin/bash

Video

Video demonstration and explanation of how docker multistage build works:

Resources

multistage-build documentation