Fix for Docker Build Errors on Older Docker Versions (v19.03 and below)

[mofaq-01]

Hi everyone,

I recently encountered a few issues while trying to build the Docker image on an older environment (Docker v19.03.1). If you see errors like:

Unsupported config option for services: 'jekyll-site'
mediaType in manifest should be 'application/vnd.docker.distribution.manifest.v2+json' not 'application/vnd.oci.image.manifest.v1+json'

Here is a quick fix that worked for me:

1. Update the Dockerfile
   Change the base image to a version compatible with older Docker manifest formats:

Change from:
FROM ruby:3.2
To:
FROM ruby:2.7-slim

2. Use Direct Docker Commands
   If docker-compose fails with "Unsupported config option," bypass it by building and running directly:

Build
docker build -t academic-site .

Run
docker run -it --rm -p 4000:4000 -v "$(pwd):/usr/src/app" -e JEKYLL_ENV=docker academic-site jekyll serve -H 0.0.0.0 -w

Hope this helps anyone else working on older machines!