Solr in Docker container unable to work with persistent data store

I have a Solr backend which I want to work with a Flask frontend. I'm planning to run both in Docker using docker-compose.

The relevant part of my docker-compose.yml looks like this:

version: '3'

services:

  solr:
    image: solr
    ports:
     - "8983:8983"
    volumes:
      - ./data:/var/solr/
    entrypoint:
    - bash
    - "-c"
    - "precreate-core stable; precreate-core unstable; precreate-core archive; exec solr -f"

[...]

volumes:
  data:

It creates on the host a persistent ./data directory, which is mounted on the guest to /var/solr. However, when I try to run it:

pc% docker-compose up              
[+] Running 2/0
 ⠿ Container src-solr-1      Recreated
 ⠿ Container src-frontend-1  Recreated
Attaching to src-frontend-1, src-solr-1
src-solr-1      | Executing /opt/solr/docker/scripts/precreate-core stable
src-solr-1      | cp: cannot create directory '/var/solr/data/stable': No such file or directory
src-solr-1      | Executing /opt/solr/docker/scripts/precreate-core unstable
src-solr-1      | Executing /opt/solr/docker/scripts/precreate-core archive
src-solr-1      | cp: cannot create directory '/var/solr/data/unstable': No such file or directory
src-solr-1      | cp: cannot create directory '/var/solr/data/archive': No such file or directory
src-solr-1      | 
src-solr-1      | Solr home directory /var/solr/data not found!
src-solr-1      | 
src-solr-1 exited with code 1
src-frontend-1 exited with code 0

The ./data folder remains empty.

I've already chowned it to 8983:8983, so it shouldn't be a permissions issue.

The error message is complaining the data directory missing inside /var/solr - and not /var/solr itself missing. You'll have to create the /data directory first, then let the cores be created inside that directory.