Docker 多阶段构建，python 和 java

Question

I'm trying to use https://docs.docker.com/develop/develop-images/multistage-build/

I need openjdk 8 and latest panda on alpine (I'm installing spark / pyspark)

I initially tried using FROM openjdk:8-alpine and then installing all python3 / pandas , but it turns out installing pandas is rather hard in alpine and you need latest alpine docker image ( Installing pandas in docker Alpine )

So I need FROM openjdk:8-alpine and From alpine:latest

My question is how do I know which directory(?) to copy from the each step?

If I do

FROM openjdk:8-alpine
From alpine:latest

I'll need copy java8 related stuff from the openjdk:8-alpine

If I do reverse

From alpine:latest
# install panda 
FROM openjdk:8-alpine

I'll need copy (what??)

Answer 1

When you use multi-stage build, you typically create an artefact (a compiled app for instance) during the first phase, and copy it to a slimmer base image on the second phase. Everything from the first stage is discarded when the final image is created.

From your comments, I think I understand that you need to start from an image that has both JDK8 AND the latest alpine. Multi-stage build doesn't help here. You'd end up just copying the JDK to the alpine:latest final stage.

I would instead copy the original Dockerfile jdk:8-alpine , change the first line to FROM alpine:3.10 and create your own base image.

If you need pyspark based on this image, you copy the original dockerfile and replace the first line FROM openjdk:8 with your base image created previously.