[feature] add some docs how to start with gunicorn

[vmario89]

Hi,

i am trying to run changedetection with gunicorn, but don't know how to pass datastore argument to the command line. played around, but i dont get it.

at first we need gunicorn (i installed changedetection with a venv):
/opt/changedetection/bin/pip install gunicorn

some experiments, which fail:

/opt/changedetection/bin/gunicorn -w 1 -b 127.0.0.1:5000 --worker-class gevent 'changedetectionio.flask_app:changedetection_app(config={"datastore_path":"/opt/changedetection/data", data:["a"]}, datastore_o={"/opt/changedetection/data"})'
/opt/changedetection/bin/gunicorn -w 1 -b 127.0.0.1:5000 --worker-class gevent 'changedetectionio.flask_app:app(datastore_o="/opt/changedetection/data")'
/opt/changedetection/bin/gunicorn -w 1 -b 127.0.0.1:5000 --worker-class gevent changedetectionio.flask_app:app
DATASTORE="/opt/changedetection/data" /opt/changedetection/bin/gunicorn -w 1 -b 127.0.0.1:5000 --worker-class gevent changedetectionio.flask_app:app
DATASTORE="/opt/changedetection/data" /opt/changedetection/bin/gunicorn -w 1 -b 127.0.0.1:5000 --worker-class gevent changedetection
/opt/changedetection/bin/gunicorn -w 1 -b 127.0.0.1:5000 --worker-class gevent 'changedetectionio.flask_app:changedetection_app(config=None, datastore_o="/opt/changedetection/data")'

before this, i used dev server, which warned about wsgi missing. so this works, but seems to be not charmant:
/opt/changedetection/bin/changedetection.io -d /opt/changedetection/data -h 127.0.0.1 -p 5000

are there any hints how to deal? searched the issues a while, did not find a good info

[dgtlmoon]

the problem with gunicorn and this app is that it's a single threaded app, it doesnt run like traditional multiple threaded gunicorns all talking to a single mysql