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 !