version: '3'

services:
  app:
    image: fireflyiii/data-importer:latest
    container_name: firefly-iii-data-importer
    restart: unless-stopped
    environment:
      # See https://docs.firefly-iii.org/data-importer/install/configure/
      - FIREFLY_III_URL=https://sub.domain.tld
      - VANITY_URL=https://sub.domain.tld
      - FIREFLY_III_ACCESS_TOKEN=ey...........
    volumes:
      - /home/colonelpanic/fireflyiii-importer/csvdrop:/import
    ports:
      - 8081:8080

This option is outlined in their docs here - https://docs.firefly-iii.org/data-importer/usage/command_line/

It looks like you could also setup a cron job that use a POST request. Docs on that here - https://docs.firefly-iii.org/data-importer/usage/post/

I run the fireflyiii/data-importer container on a separate server with Traefik as the reverse proxy and Authelia (for ForwardAuth) to force logging in. This is probably overkill for a single user and why I recommend just running this from your workstation. Docker and docker-compose need to be installed.

Copy the docker-compose yaml below and enter your environment variables. Save it in a folder on your workstation.

docker-compose.yml:

version: '3'

services:
  app:
    image: fireflyiii/data-importer:latest
    container_name: firefly-iii-data-importer
    restart: unless-stopped
    environment:
      # See https://docs.firefly-iii.org/data-importer/install/configure/
      - FIREFLY_III_URL=https://sub.domain.tld
      - VANITY_URL=https://sub.domain.tld
      - FIREFLY_III_ACCESS_TOKEN=ey...........
      #- FIREFLY_III_CLIENT_ID=
      #- NORDIGEN_ID=
      #- NORDIGEN_KEY=
      #- SPECTRE_APP_ID=
      #- SPECTRE_SECRET=
    ports:
      - 8081:8080

Once you've modified the file with all of your environment variables you just need to navigate to the folder containing the docker-compose file in a terminal and run docker-compose up -d. This will start the container in detached mode. Once it is up and running you can access the data-importer at http://localhost:8081/

When you're done importing you can go back to the directory with the docker-compose file and run docker-compose down to stop the container.

I can share my Traefik labels for anyone interested in setting up Forward Auth through Authelia.

Hope this helps!

Is that how others are using it?

https://docs.firefly-iii.org/importing-data/introduction