gubatron/dynamic_dockerfile_host_architecture.md

## dynamic_dockerfile_host_architecture.md

      
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              dynamic_dockerfile_host_architecture.md
            
          
    How to build your Docker image using the same Dockerfile regardless of the host architecture

Problem

If you are now using docker on a Mac M1 (arm64 platform), you don't want to use amd64 as the architecture for your Linux Images.
You could have 2 lines on your Dockerfile and comment each one depending on where you're building the image
Dockerfile
# Building on Apple Silicon host
FROM --platform=linux/arm64 ubuntu:20.04

# Building on Intel/x86_64 host
#FROM --platform=linux/amd64 ubuntu:20.04

Eventually this becomes very annoying.
Solution

You can pass a build time argument when you invoke docker build
Put this on your Dockerfile:
ARG BUILDPLATFORM
FROM --platform=linux/$BUILDPLATFORM ubuntu:20.04

On your docker_build_image.sh script:
export BUILDPLATFORM=`uname -m`
docker build --build-arg BUILDPLATFORM=${BUILDPLATFORM} -t myimagename .