Heroku: how to deploy a Django app in less 10 minutes!

If you're tired of dealing with load balancing, routing and cloud monitoring and would like to focus on just lambda function, list comprehension or class-based view, then this is the talk for you.

Heroku is the Platform as a Service (PaaS) platform that allows developers to create, run and manage applications entirely in the cloud. To be provided as a service not only the hardware, but also the platform that abstracts the hardware itself and allows you to take advantage of features that allow you to achieve automatic balancing, deployment management and more.

The advantage for the user is to focus exclusively on the development of the application without getting lost in the analysis of problems related to the environment in which it must be distributed, thus obtaining the necessary scalability and reliability.

Transcript

1. Heroku: how to deploy a Django app in less 10 minutes! Sabatino Severino sab@pentatechnology.it Firenze 21/04/2018
2. About Me • Python Developer & Data Scientist • Deep Learning Analytics for Satellite Imagery • Official Pycon9 App Developer sab@pentatechnology.it @bsab linkedin.com/in/severinosab
3. Heroku: how to deploy a Django app in less 10 minutes!
4. “manually configure and maintain virtualized servers that run our application“ Deployment
5. Let me tell you a story….
6. 1. choose and set up an EC2 2. select a CPU, amounts of RAM and storage 3. set up SSH 4. ….
7. Security
8. Scaling
10. Hire a DevOps Engineer 7
11. PAAS
12. What is PAAS? Platform-as-a-service enables developers to create innovative applications without operational overhead around configuration, deployment and management.
13. Cloud vendors manages infrastructure. You manage platforms and apps IaaS Layers of infrastructure Cloud vendors manages infrastructure and platforms. You manage apps PaaS Cloud vendors manages infrastructure, platforms and apps. You manage nothing... SaaS Infrastructure Applications Platform Infrastructure Applications Platform Infrastructure Applications Platform Amazon EC2, Windows Azure, Rackspace, Google Compute Engine AWS Elastic Beanstalk, Windows Azure, Heroku, Force.com, Google App Engine, Apache Stratos Google Apps, Microsoft Office 365
14. Efficient, Secure, Elastic • Applications co-located on a few-servers • Drastically reduces resources • Add/Remove servers depending on load • All secure using SELinux or LXC
15. Let them do boring stuff
16. Who are the players?
17. What is Heroku? Heroku is a platform as a service (PaaS) that enables developers to build, run, and operate applications entirely in the cloud.
20. Boosting app development with Add-Ons
21. I II III IV Codebase 12 Factor App Dependencies Config Concurrency Disposability Dev/Prod parity Port Binding V VI VII VIII IX X XI XII Backing Services Build, release, run Processes Logs Admin processes 12factor.net
22. Heroku core language support Virtually every language you can think of is supported by community buildpacks https://devcenter.heroku.com/articles/third-party-buildpacks
23. Dynos
24. Dynos
25. Scaling
27. Let’s go!
28. Preparing the application • Add a Procfile in the project root • Add requirements.txt file with all the requirements in the project root • Add Gunicorn to requirements.txt • A runtime.txt to specify the correct Python version in the project root • Configure whitenoise to serve static files
29. web: gunicorn pycon9_demo.wsgi --log-file - The Procfile
30. Django==1.11 django-material django-fieldbook fieldbook_py python-decouple gunicorn==19.6.0 whitenoise==3.2 psycopg2==2.6.2 dj-database-url==0.4.1 requirements.txt $ pip freeze > requirements.txt
31. python-2.7.14 runtime.txt
32. PROJECT_ROOT = os.path.dirname(os.path.abspath(__file__)) # Static files (CSS, JavaScript, Images) # https://docs.djangoproject.com/en/1.9/howto/static-files/ STATIC_ROOT = os.path.join(PROJECT_ROOT, 'staticfiles') STATIC_URL = '/static/' # Extra places for collectstatic to find static files. STATICFILES_DIRS = ( os.path.join(PROJECT_ROOT, 'static'), ) Set Up The Static Assets Update the settings.py
33. import os from django.core.wsgi import get_wsgi_application from whitenoise.django import DjangoWhiteNoise os.environ.setdefault("DJANGO_SETTINGS_MODULE", "pycon9_demo.settings") application = get_wsgi_application() application = DjangoWhiteNoise(application) Update the wsgi.py file: STATICFILES_STORAGE = 'whitenoise.django.CompressedManifestStaticFilesStorage Update the settings.py WhiteNoise http://whitenoise.evans.io/en/stable/
34. Set Up the Environment Variables Update the settings.py SECRET_KEY = config('SECRET_KEY') DEBUG = config('DEBUG', default=False, cast=bool) DATABASES = { 'default': dj_database_url.config( default=config('DATABASE_URL') ) } • python-decouple: Strictly separate the settings parameters from your source code. • dj-database-url: This simple Django utility allows you to utilize the 12factor inspired DATABASE_URL environment variable to configure your Django application.
35. Let’s get the deployment started!
36. $ git clone https://github.com/bsab/pycon9_demo.git && cd pycon9_demo 1) clone the repository you want to deploy : $ heroku login 2) login to Heroku using the CLI:
37. $ heroku create pycon9-demo 3) inside the project root, create the Heroku App: Creating ⬢ pycon9-demo... done https://pycon9-demo.herokuapp.com/ | https://git.heroku.com/pycon9-demo.git *You can omit the app name parameter (in my case, django-fieldbook), then Heroku will pick a name for you.
38. $ heroku addons:create heroku-postgresql:hobby-dev 4) add a PostgreSQL database to your app Creating postgresql-metric-21979... done, (free) Adding postgresql-metric-21979 to pycon9_demo... done Setting DATABASE_URL and restarting pycon9_demo... done, v4 Database has been created and is available
39. $ git push heroku master 5) push to deploy Counting objects: 1999, done. Delta compression using up to 4 threads. Compressing objects: 100% (616/616), done. Writing objects: 100% (1999/1999), 461.28 KiB | 0 bytes/s, done. Total 1999 (delta 1139), reused 1983 (delta 1131) remote: Compressing source files... done. remote: Building source: remote: remote: -----> Python app detected remote: -----> Installing python-2.7.13 remote: $ pip install -r requirements.txt ... remote: -----> Launching... remote: Released v5 remote: https://pycon9-demo.herokuapp.com/ deployed to Heroku remote: remote: Verifying deploy.... done. To https://git.heroku.com/pycon9_demo.git * [new branch] master -> master
40. $ heroku run python manage.py migrate 6) migrate the database Running python manage.py migrate on ⬢ pycon9_demo... up, run.9352 Operations to perform: Apply all migrations: questions, sessions, authentication, articles, feeds, contenttypes, messenger, activities, auth Running migrations: Rendering model states... DONE Applying contenttypes.0001_initial... OK Applying auth.0001_initial... OK Applying questions.0001_initial... OK Applying feeds.0001_initial... OK Applying articles.0001_initial... OK Applying activities.0001_initial... OK Applying contenttypes.0002_remove_content_type_name... OK Applying auth.0002_alter_permission_name_max_length... OK Applying auth.0003_alter_user_email_max_length... OK Applying auth.0004_alter_user_username_opts... OK Applying auth.0005_alter_user_last_login_null... OK Applying auth.0006_require_contenttypes_0002... OK Applying auth.0007_alter_validators_add_error_messages... OK Applying authentication.0001_initial... OK Applying messenger.0001_initial... OK Applying sessions.0001_initial... OK
41. And there you go! https://pycon9-demo.herokuapp.com/
42. Total Time:
43. Wrap Up • The application “sleeps” after 30 minutes of inactivity. The first access after it might be slow. • The free PostgreSQL database has a limitation of 10K rows. • If you need to store user uploaded files (media), you will need a service to store the files (Amazon S3)
44. So what? Use Heroku: • for small personal projects • if you are an agency • get started very quickly • just want to play around • a Free SSL Certificate!
45. Don’t use Heroku: • if you can afford to have an expert in devops • for production load with SLA’s • additional control over your infrastructure
46. Thanks