Multiple images, one Dockerfile

Question

How to create two images in one Dockerfile, they only copy different files.

Shouldn\'t this produce two images img1 & img2, ins

Answer 1

You can build multiple images from one Docker file by running docker build for each build stage name want to pick out of the Dockerfile (FROM alpine as name).

By default docker builds the image from the last command in the Dockerfile, however you can target the build to an intermediate layer. Extending from the example Dockerfile in the question, one can:

docker build -t image1 --target img1 .

ref: https://docs.docker.com/engine/reference/commandline/build/#specifying-target-build-stage---target

Answer 2

You can use a docker-compose file using the target option:

version: '3.4'
services:
  img1:
    build:
      context: .
      target: img1
  img2:
    build:
      context: .
      target: img2

using your Dockerfile with the following content:

FROM alpine as img1
COPY file1.txt .

FROM alpine as img2
COPY file2.txt .