In this tutorial, you will learn how to deploy a Django API to Heroku. Here’s what you need to do to go from zero to deployed on Heroku with a Django + Postgres application from the command line.
pip install whitenoise
pip install gunicorn
pip install dj-database-url
pip install django-cors-headers
pip install psycopg2
Create two files in the project root.
touch Procfile
runtime.txt
Here is my current directory structure
.
├── Procfile
├── apps
├── manage.py
├── myproject
├── requirements.txt
└── runtime.txt
Let's freeze the requirements.txt file
pip freeze -> requirements.txt
You should see something like this:
asgiref==version
dj-database-url==version
Django==version
django-cors-headers==version
django-heroku==version
djangorestframework==version
gunicorn==version
psycopg2==version
pytz==version
sqlparse==version
whitenoise==version
By default, Django does not serve static files in production. Hence, we will use WhiteNoise for serving static assets in production. So let's configure the STATIC-related parameters in settings.py, make sure to put these configurations are at the end of settings.py
PROJECT_ROOT = os.path.dirname(os.path.abspath(__file__))
STATIC_URL = '/static/'
# Extra places for collectstatic to find static files.
STATICFILES_DIRS = (
os.path.join(PROJECT_ROOT, 'static'),
)If you’re familiar with Django you’ll know what to do. If you’re just getting started with a new Django project then you’ll need add the following to the bottom of your settings.py file:
STATIC_ROOT = os.path.join(BASE_DIR, 'staticfiles')Edit your settings.py file and add WhiteNoise to the MIDDLEWARE list. The WhiteNoise middleware should be placed directly after the Django SecurityMiddleware (if you are using it) and before all other middleware:
MIDDLEWARE = [
'django.middleware.security.SecurityMiddleware',
'whitenoise.middleware.WhiteNoiseMiddleware',
# ...
]Edit the Procfile file in the project root with the following content
web: gunicorn <project_name>.wsgi --log-file -
Edit the runtime.txt file in the project root with the following content, For example, I'll be using Python 3.6.8
python-3.6.8
If you like more information about Heroku supported runtime enviroments please visit: https://devcenter.heroku.com/articles/python-support#supported-runtimes
We use the dj-database-url library to extract database configurations from the environment.
For Django applications, a Heroku Postgres hobby-dev database is automatically provisioned. This populates the DATABASE_URL environment variable.
To set up the database, we will add the following code in settings.py:
import os
import dj_database_urlAfter the databases setting add the following
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': 'sample123',
'USER': 'suresh',
'PASSWORD': '',
'HOST': 'localhost',
'PORT': '',
}
}
# dj-database-url settings
# Update database configuration with $DATABASE_URL.
db_from_env = dj_database_url.config()
DATABASES['default'].update(db_from_env)Alright, enough configuration. Let’s get the deployment started. First, let's initialize our gitrepo in the In your project root
git init
Take a look at what files are ready to be committed to git
git status
Some of these files we don’t want to track in git. Why? Well, some of them can be created each time you run the program, so it is a waste of space and distracting to check them into git. To handle this, we create a file called .gitignore (like git ignore, but all one word) in the base directory of our project. Then, we write the file or folder names or paths that we want to exclude from git.
git add .
git commit -m "Initial commit"
touch .gitignore
add the following to the .gitignore file
# Byte-compiled / optimized / DLL files
__pycache__/
*.py[cod]
*$py.class
# C extensions
*.so
# Distribution / packaging
.Python
env/
build/
develop-eggs/
dist/
downloads/
eggs/
.eggs/
lib/
lib64/
parts/
sdist/
var/
wheels/
*.egg-info/
.installed.cfg
*.egg
# Django stuff:
*.log
local_settings.py
# pyenv
.python-version
# dotenv
.env
# virtualenv
.venv
venv/
ENV/
# mypy
.mypy_cache/
# vscode
.vscode/
Now let's add the django cors header to the installed apps
INSTALLED_APPS = [
...,
'django.contrib.staticfiles',
'corsheaders',
...
]You will also need to add a middleware class to listen in on responses:
MIDDLEWARE = [ # Or MIDDLEWARE_CLASSES on Django < 1.10
...
'corsheaders.middleware.CorsMiddleware',
'django.middleware.common.CommonMiddleware',
...
]Add CORS_ORIGIN_ALLOW_ALL before the ROOT_URLCONF
CORS_ORIGIN_ALLOW_ALL = True
ROOT_URLCONF = 'myproject.urls'Heroku actually uses a cli to control their deployments. So let’s install it.
brew install heroku
Now, we need to “log in” to the local cli. This command will ask for your credentials. When you type in your password, you won’t see it, but it is working. Press enter when you are done.
heroku login
heroku create <app_name>
Now let's setup the databases. The following commands create postgresql database on heroku for you app and fetch its url.
heroku addons:create heroku-postgresql:hobby-dev
heroku config -s | grep DATABASE_URL
Run the following command to test Heroku deployment locally. Make sure you're the root of the project.
heroku local web
This will run the Procfile and consequently you can debug any errors if any on your local machine. You should see an output similar to this.
4:30:46 PM web.1 | [2020-05-12 16:30:46 -0400] [4314] [INFO] Starting gunicorn 20.0.4
4:30:47 PM web.1 | [2020-05-12 16:30:46 -0400] [4314] [INFO] Listening at: http://0.0.0.0:5000 (4314)
4:30:47 PM web.1 | [2020-05-12 16:30:46 -0400] [4314] [INFO] Using worker: sync
4:30:47 PM web.1 | [2020-05-12 16:30:46 -0400] [4317] [INFO] Booting worker with pid: 4317
Now visit http://0.0.0.0:5000 and see if you can see the Django application.
Let's run the db migrations
heroku run python manage.py migrate
heroku run python manage.py makemigrations
heroku run python manage.py createsuperuser
heroku run python manage.py migrate
Sometimes, you may not want Heroku to run collectstatic on your behalf. You can disable the collectstatic build step with the DISABLE_COLLECTSTATIC configuration:
heroku config:set DISABLE_COLLECTSTATIC=1
Finally, we are now ready to deploy our application. Follow these steps to successfully deploy to Heroku. Commit all changes to git.
git add .
git commit -m "deployment ready"
git push heroku master
heroku open