The volume manager is pure microservice rest api. It's defined with API first approach with Openapi v3 and implemented as a Flask application.
cd server
# setup virtual env
python3.7 -m venv venv
# install dependencies
pip install --no-cache-dir -r requirements.txt
# activate virtual env
source venv/bin/activate
# run flask backend
export FLASK_ENV=development
python -m volumemanager
Open your browser and go to http://0.0.0.0:8080/api/ui/ to see the REST api ui
When running in Cloudharness the url for the api ui is https://volumemanager.cloudharness.metacell.us/api/ui/
Volume manager uses openapi for definition of the (REST) api .
This application is based on Flask