Can't make it work with Solr 8 with docker

[royalidrees53]

Using Solr in docker using this stack

version: '3'
services:
  solr:
    image: solr:8
    ports:
     - "8983:8983"
    volumes:
      - solr-data:/var/solr
    command:
      - solr-precreate
      - gettingstarted
volumes:
  solr-data:
    external: true
    

But keep getting this error "msg":"undefined field type" on running bundle exec rake sunspot:reindex, Found in community that it has to do with the schema that sunspot is using is different from latest schema in solr 8,

Is sunspot working with latest solr?

[mameier]

sunspot needs another core schema than "gettingstarted".
You find the "core" in ./solr/configsets/sunspot
BUT: the current core only works with solr:6
There are patches that work with solr:7 in examples/solr7_core
The last commit (nov 2019) states "Update example core to work with Solr 8" but is doesn't.

With the patched core I can run solr:7 with:

version: '3'
  services:
    solr:
      image: solr:7
      ports:
        - "8383:8983"
      volumes:
        - ./solr/data:/opt/solr/server/solr/mycores
        - ./solr/configsets:/configsets
      command:
        - solr-precreate
        - my_core_name
        - /configsets/sunspot