Tutorial for installing Heroku's command-line tool, and launch an example Django website.

Who is this guide for

• This is for brand new Python users, including coding class students who want a simple and to-the-point guide on getting Heroku working on their system to launch Python websites.

• This guide assumes you already have fundamental Bash and git knowledge.

• This guide does not support Windows. It assumes you use either macOS or Ubuntu GNU/Linux.

This was original created for Kickstart Coding, the affordable, inclusive, and intensive coding course teaching cutting-edge Python / Django and JavaScript / React web development in Oakland, CA. Learn more and enroll here.

What is Heroku?

Heroku is a company that will run an HTTP server application for you, and expose it to the internet.

They will do the heavy lifting of installing PyPI dependencies and making sure the right HTTP requests get to your servers (routing), you in turn need to only make sure your application is properly configured. Also important: They have a "freemium" payment model, where there is a "free-tier" that is great for learning without spending any money.

Heroku is now a subsidiary of SalesForce, and in turn rents its server space according to an agreement with Amazon Web Services.

Key Terms

• Heroku (the business) - a company that will run your HTTP server application for you, and expose it to the web.

• heroku (the CLI command) - A tool that Heroku the company has developed which we will use for interacting with your Heroku account, and launching applications.

• heroku app - One particular application you are running on a Heroku server.

• heroku add-on - Extra stuff your application needs, such as databases or media file services. These might cost money, and might be provided by a third party.

Guide

Now that you know a little about Heroku, it's time to install their CLI tool on your system and get used to using it.

Getting a Heroku account

• First, go to the Heroku.com website and sign up for an account. Remember your username and password, you will be using it in a moment.

• You may want to add in your credit card information -- although optional, it unlocks more free apps and add-ons at once even if you never buy anything.

Installing the Heroku Tool

Ubuntu Linux

Either use the Ubuntu Software Center (search for Heroku and click Install), or run the following command:

sudo snap install --classic heroku

macOS

Run the following command:

brew install heroku/brew/heroku

Logging in

Login to Heroku (should only have to do this once):

heroku login

Using Heroku

Broad concepts:

• For every web project you are working on, if you want to publish it, you should create for it a Heroku app.

• Heroku acts a little like GitHub: They provide a remote Git server that we can push to. So, when you create an app, you are also creating a remote repo to store your code (much like GitHub).

• Whenever Heroku receives code from us via a git push, they will then try to run that code on their servers, and expose it to the world.

Python project

For this tutorial, this very repo contains an example Django project you can launch! Go ahead and git clone this repo, to use it as your example Django project to launch.

https://github.com/kickstartcoding/heroku-getting-started/

Already have a Django project? If you started it using django-admin startproject, then follow this guide instead.

Creating a new Heroku app

Every time you want to launch a brand new Python project, you will need to create a new Heroku app for it. These are the steps to both create a new heroku app, and link your git repo to it.

1. Go to the directory of your project.

   • Ensure your project has a Procfile. If you are using this example Django repo, you will already have a Procfile. This tells Heroku which file is the main "entry point" to your server, in other words, which file to run to kick everything off.
   • Ensure your Django project has a Pipfile (or requirements.txt). Again, if you are using this example, you will already have a Pipfile.

2. Important: Your project MUST be in a git repository.

   • If you git clone this repo, then you are good on this front, also.
   • You can either do this the normal way by going to GitHub and creating a new repo, then cloning that, OR you can use the "git init" command to make a local-only repo. However you do it, Heroku absolutely requires your project to be in a single git repo, such that the Procfile, Pipfile, and manage.py are all at the "top level" next to README.md and .git, etc.

3. Create a new Heroku Application on your account for your project. This

command should be executed within your git project directory:

heroku create

4. Ensure that your git repo is now linked to a Heroku remote, in addition to

GitHub:

# You should see both "origin" twice and "heroku" twice (4 lines) when running
# the following git command:
git remote -v

Launching your Heroku app

If all went well, you are good to go! Deploy your app to Heroku:

git push heroku master

If it's working, you should see text like "Python app detected", then after a 30 seconds or so, something like this:

remote: -----> Launching...
remote:        Released v4
remote:        https://secure-lake-12038.herokuapp.com/ deployed to

That strange URL "secure-lake-12038" will be a different combo of random words and numbers for you, but will be the URL of your new app! Click on that link or copy and paste it into your browser to see your application live for the world to see.

Making updates to your project

As you work on your project, after every change that you want to test on Heroku, make a commit (git add -A, git commit -m) and then repeat the previous last step (git push heroku master).

Heroku Tips

• By default, they pick a weird, random domain name, but you can customize it later if you want to have a custom name, or even a purchased domain name.

• If you want to launch code to Heroku, it must be in a brand new commit. So, whenever you want to relaunch to the world, you will need to create a new commit.