QGIS-Server-light is a python worker process which uses pyqgis to render a set of layers into an image. It is backed by Redis as a queue system. All configuration happens at runtime through a lean interface.
docker run --rm -d -p 1234:6379 --name georama-redis redis
docker run --rm -e QSL_REDIS_URL=redis://localhost:1234 --net host ghcr.io/opengisch/qgis-server-light:latest
Create an .env file and put the content of .env.example into it. Adapt as needed.
docker compose up -d
For further details and a better understanding please refer to the documentation.