Django - Deploying on Heroku

14th February, 2019

Heroku Deployment

Basic set up

Create a Heroku account
Create new app and choose the location (server location)
Go to Resources and add Heroku Postgres (for PostgreSQL database) and Heroku Redis (for cache) and Deploy Hook- Http Post (for deployment notification in Slack for e.g.)
Download and install Heroku CLI

Django Set Up

Create a Django app
Create requirements.txt file in the project folder

Install following libraries

pip install dj-database-url # for accessing database
pip install gunicorn # for running Python HTTP server

Add dj-database-url==XX & gunicorn==XX to requirements.txt file.
Add the following environment variables:
- DATABASE_URL
- REDIS_URL

Go to settings.py file and add the following:

For Database settings:

config = {
   key: value for key, value in os.environ.items()
}
heroku_database_url = config.get('DATABASE_URL', None)
if heroku_database_url:
    # heroku production setting
    import dj_database_url
    DATABASES = {
       'default': dj_database_url.parse(heroku_database_url),
    }
else:
    # development/test setting
    DATABASES = {
       'default': {
           'ENGINE': 'django.db.backends.postgresql',
           'NAME': 'postgres',
       }
    }

For Cache setting:

open_redis_url = config.get('REDIS_URL')
if not open_redis_url:    
    CACHES = {
        'default': {
            'BACKEND': 'django.core.cache.backends.dummy.DummyCache',
        }
    }
else:
    CACHES = {
        "default": {
            "BACKEND": "django_redis.cache.RedisCache",
            "LOCATION": open_redis_url,
            "OPTIONS": {
                "CLIENT_CLASS": "django_redis.client.DefaultClient",
                "IGNORE_EXCEPTIONS": True,
            },
            'KEY_PREFIX': DEP_NAME,
            'VERSION': VERSION,
            'TIMEOUT': 86400,  # 1 day
        },
    }

Create gunicorn_cofig.py in project folder and add

import os
import multiprocessing

size = int(os.getenv("SIZE", 1))
# Maximum 5 worker per 128MB
workers = min(multiprocessing.cpu_count() * 2 + 1, size * 1)
timeout = int(os.getenv("GUNICORN_TIMEOUT", 120))

Create Procfile in project folder and add

web: gunicorn <django-project-name>.wsgi:application --config gunicorn_config.py

Create runtime.txt in project folder and add
```
python-3.5.2
```
Commit your changes in git

Deploy using terminal:

$ heroku login$ heroku git:remote -a <heroku app name>
$ git push heroku <local git branch name>:master

Tip:

$ heroku run 'bash' --app <heroku_app_name> # to run bash on heroku terminal
$ python manage.py createsuperuser # to create superuser in heroku

Enjoy !

Django - Deploying on Heroku

Heroku Deployment

Basic set up

Django Set Up

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