settings.py

import os

def env_var(name):
    try:
        return str(os.environ[name])
    except:
        raise KeyError

        # Database
# https://docs.djangoproject.com/en/2.2/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'employees',
        'USER': 'root',
        'PASSWORD':env_var('DB_PASS'),
        'HOST':'0.0.0.0',
        'PORT':''
    }
}