Steps I followed to set up gunicorn service in ubuntu for flask restless

gunicorn-flask.txt

I used anaconda as my python vendor.
So first install anaconda.
Then set path in .profile in home directory.
--> PATH="$HOME/bin:$HOME/.local/bin:$HOME/anaconda3/bin:$PATH"
then create a virtual environment using conda as 
:  conda create --name your_name_for_env python=3.4
this will create named env directory inside anaconda3/envs
do source activate your_name_for_env
now go to your project directory and install dependencies using pip as:
--> pip install -r requirements.txt
you must include gunicorn in your requirements.txt as we r establishing gunicorn sevice
Now you are ready to write gunicorn
do this:
-> sudo nano /etc/systemd/system/gunicorn.service
example for the service:
[Unit]
Description=gunicorn daemon
After=network.target

[Service]
User=alpha
Group=www-data
WorkingDirectory=/home/alpha/fms-backend-flask-restless
ExecStart=/home/alpha/anaconda3/envs/flask_rest_fms/bin/gunicorn --access-logfile - --workers 4 --bind 192.168.1.236:9090 api:app

[Install]
WantedBy=multi-user.target

now do:
sudo systemctl start gunicorn
sudo systemctl enable gunicorn

It's very clear and work very well, thanks!

Glad it helped you, I did it long time ago :D