A basic example/tutorial showing GitHub OAuth in a Phoenix
App
using elixir-auth-github
.
Try it: elixir-auth-github-demo.fly.dev
No data is stored. Try and break it. Open an issue if you spot something.
elixir-auth-github
demo- Why? 🤷
- What? 💭
- Who? 👥
- How? 💻
We love having detailed docs and examples that explain exactly how to get up-and-running. We write examples because we want them for ourselves, if you find them useful, please ⭐️ the repo to let us know.
This project is a barebones demo
of using
elixir-auth-github
to add "Sign-in with GitHub" support
to any Phoenix App.
This demos is intended for people of all Elixir/Phoenix skill levels. Anyone who wants the "Sign-in with GitHub" functionality without the extra steps to configure a whole auth framework.
Following all the steps in this example should take around 10 minutes. However if you get stuck, please don't suffer in silence! Get help by opening an issue: dwyl/elixir-auth-github/issues
This example follows the step-by-instructions in the docs dwyl/elixir-auth-github
Create a new project if you don't already have one:
If you're adding
elixir_auth_github
to an existing app, you can skip this step.
Just make sure your app is in a known working state before proceeding.
mix phx.new app
Note: In creating this demo app we ran the command with the following flags:
mix phx.new app --no-assets --no-dashboard --no-ecto --no-gettext --no-mailer
to keep the project as basic as possible. You may need some or all of the features ofPhoenix
, so check which flags are applicable to you.
If prompted to install dependencies:
Fetch and install dependencies? [Yn]
Type y
and hit the [Enter]
key to install.
You should see something like this:
* running mix deps.get
* running mix deps.compile
Make sure that everything works before proceeding:
mix test
You should see:
Generated app app
...
Finished in 0.02 seconds
3 tests, 0 failures
The default tests pass and you know phoenix is compiling.
Run the web application:
mix phx.server
and visit the endpoint in your web browser: http://localhost:4000/
Open your mix.exs
file and add the following line to your deps
list:
def deps do
[
{:elixir_auth_github, "~> 1.6.5"}
]
end
Run the mix deps.get
command to download.
Create your GitHub App and download the API keys
by follow the instructions in:
/create-github-app-guide.md
By the end of this step you should have these two environment variables defined:
GITHUB_CLIENT_ID=631770888008-6n0oruvsm16kbkqg6u76p5cv5kfkcekt
GITHUB_CLIENT_SECRET=MHxv6-RGF5nheXnxh1b0LNDq
⚠️ Don't worry, these keys aren't valid. They are just here for illustration purposes.
We need to create two files in order to handle the requests to the GitHub OAuth API and display data to people using our app.
In order to process and display the data returned by the GitHub OAuth2 API,
we need to create a new controller
.
Create a new file called
lib/app_web/controllers/github_auth_controller.ex
and add the following code:
defmodule AppWeb.GithubAuthController do
use AppWeb, :controller
@doc """
`index/2` handles the callback from GitHub Auth API redirect.
"""
def index(conn, %{"code" => code}) do
{:ok, profile} = ElixirAuthGithub.github_auth(code)
render(conn, :welcome, [layout: false, profile: profile])
end
end
This code does 3 things:
- Create a one-time auth token based on the response
code
sent by GitHub after the person authenticates. - Request the person's profile data from GitHub based on an
access_token
- Renders a
:welcome
view displaying some profile data to confirm that login with GitHub was successful.
Note: we are placing the
welcome.html.eex
template in thetemplate/page
directory to save having to create any more directories and view files. You are free to organise your code however you prefer.
Create a new file with the following path:
lib/app_web/controllers/github_auth_html/welcome.html.heex
And type (or paste) the following code in it:
<script src="https://cdn.tailwindcss.com"></script>
<section class="flex flex-col items-center justify-center px-6 py-8 mx-auto md:h-screen lg:py-0">
<h1 class="text-4xl text-center font-bold leading-tight tracking-tight text-gray-900 md:text-2xl">
Welcome <%= @profile.name %>!
<img class="float-right h-8 w-8 rounded-full" alt="avatar image" width="32px"
src={@profile.avatar_url} />
</h1>
<p> You are <strong>signed in</strong>
with your <strong>GitHub Account</strong> <br />
<strong style="color:teal;"><%= @profile.email %></strong>
</p>
</section>
Note: There's a fair amount of
TailwindCSS
sprinkled in that template, if you're new toTailwind
or need a refresher, please see: /learn-tailwind
Invoking ElixirAuthGithub.github_auth(code)
in the GithubAuthController
index
function will
make an HTTP request to the GitHub Auth API
and will return {:ok, profile}
where the profile
data
has the following format:
%{
followers_url: "https://api.github.com/users/nelsonic/followers",
public_repos: 291,
plan: %{
"collaborators" => 0,
"name" => "pro",
"private_repos" => 9999,
"space" => 976562499
},
created_at: "2010-02-02T08:44:49Z",
name: "Nelson",
company: "@dwyl",
email: "[email protected]",
two_factor_authentication: true,
starred_url: "https://api.github.com/users/nelsonic/starred{/owner}{/repo}",
id: 194400,
following: 173,
login: "nelsonic",
collaborators: 28,
avatar_url: "https://avatars3.githubusercontent.com/u/194400?v=4",
etc: "you get the idea ..."
}
More info: https://developer.github.com/v3/users
Use this data how you see fit. (obviously treat it with respect, only store what you need and keep it secure!)
Create a file with the path:
lib/app_web/controllers/github_auth_html.ex
and add the following code to it:
defmodule AppWeb.GithubAuthHTML do
use AppWeb, :html
embed_templates "github_auth_html/*"
end
This is required so Phoenix
knows where to find the template.
Open your lib/app_web/router.ex
file
and locate the section that looks like scope "/", AppWeb do
Add the following line:
get "/auth/github/callback", GithubAuthController, :index
That will direct the API request response
to the GithubAuthController
:index
function we defined above.
In order to display the "Sign-in with GitHub" button in the UI, we need to generate the URL for the button in the relevant controller, and pass it to the template.
Open the lib/app_web/controllers/page_controller.ex
file
and update the index
function:
From:
def home(conn, _params) do
# The home page is often custom made,
# so skip the default app layout.
render(conn, :home, layout: false)
end
To:
def home(conn, _params) do
oauth_github_url = ElixirAuthGithub.login_url_with_scope(["user:email"])
render(conn, :home, [layout: false, oauth_github_url: oauth_github_url])
end
Open the /lib/app_web/controllers/page_html/home.html.heex
file
and type (or paste) the following code:
<script src="https://cdn.tailwindcss.com"></script>
<section class="">
<div class="flex flex-col items-center justify-center px-6 py-8 mx-auto md:h-screen lg:py-0">
<div class="w-full bg-white rounded-lg shadow dark:border md:mt-0 sm:max-w-md xl:p-0 dark:bg-gray-200 dark:border-gray-700">
<div class="p-6 space-y-4 md:space-y-6 sm:p-8">
<h1 class="text-3xl text-center font-bold leading-tight tracking-tight text-gray-900 md:text-2xl">
Welcome to Awesome App!
</h1>
<p class="text-center">
To get started, login with your GitHub Account:
</p>
<a href={ @oauth_github_url } class="py-8 flex items-center justify-center">
<img src="https://i.imgur.com/qwoHBIZ.png" alt="Sign in with GitHub" />
</a>
</div>
</div>
</div>
</section>
Note: the login button is an image for brevity. In our production version we use
CSS
andSVG
, see: /elixir-auth-github#optimised-svgcss-button
Run the app with the command:
mix phx.server
Visit the home page of the app where you will see a "Sign in with GitHub" button: http://localhost:4000
Once the user authorizes the App, they will be redirected back to the Phoenix App and will see welcome message:
This guide is meant to get your Phoenix
App up-and-running
with elixir-auth-github
on localhost
.
The demo is deployed to Fly.io to demonstrate that everything works as expected:
No data is saved by the demo app, so feel free to try an break it!
https://elixir-auth-github-demo.fly.dev
Authorization screen:
Welcome (success):
If you want to deploy your own Phoenix
App to Fly.io,
simply follow the official Elixir
Getting Started guide:
fly.io/docs/elixir/getting-started
fly launch
Speed through the prompts to create the App and then add the add the 3 required environment variables:
fly secrets set GITHUB_CLIENT_ID=4458109151751aetc
fly secrets set GITHUB_CLIENT_SECRET=256df107df6454001a90d667fetc
SECRET_KEY_BASE=fephli94y1u1X7F8Snh9RUvz5l0fd1ySaz9WtzaUAX+NmfB0uE2xwetc
Note: none of these keys are valid. They are just for illustration purposes. Follow the instructions: dwyl/elixir-auth-google/blob/main/create-google-app-guide.md to get your Google App keys.
Refer to the
Dockerfile
and
fly.toml
in this demo project
if you need an example.
Recommended reading: "Deploying with Releases" hexdocs.pm/phoenix/releases.html
For Continuous Deployment to Fly.io, read: fly.io/docs/app-guides/continuous-deployment-with-github-actions