This repository provides an example of how to use Flask-Dance to connect
to Google as an OAuth client. The example code is in google.py --
all the other files in this repository are secondary. You can run this example
code locally, or deploy it to Heroku for free to see how it runs in a
production-style environment.
Heroku is a great way to get up and running fast, and you don't even need to open the terminal!
It's easy, and it's free! Just click on this button:
You can leave all the fields at their default values: we'll fill them in later. The only thing that matters right now is the app name, and Heroku will autogenerate a name for you if you leave that field blank. Using an autogenerated name is perfectly fine, just take note of what it is.
Note that your app isn't functional yet, and if you try to visit it right now, you'll end up at a Google 404 page. That's OK, we're not done yet!
Visit the Google Developers Console at https://console.developers.google.com and create a new project. In the "APIs & auth" section, click on "Credentials", and then click the "Create a new Client ID" button. Select "Web Application" for the application type, and click the "Configure consent screen" button. Put in your application information, and click Save. Once you’ve done that, you’ll see two new fields: "Authorized JavaScript origins" and "Authorized redirect URIs". You need to set the correct authorized redirect URI for the OAuth system to work correctly.
To set the correct authorized redirect URI, you'll need that
app name from Heroku. The correct authorized redirect URI is
https://APPNAME.herokuapp.com/login/google/authorized. For example,
if Heroku assigned you an app name of peaceful-lake, your authorization
callback URL must be
https://peaceful-lake.herokuapp.com/login/google/authorized. Once you've
put that in, click "Create Client ID". Google will give you a client ID and
client secret, which we'll use in the next step.
Go to Heroku and visit the settings page for your app. (You can get there from your Heroku dashboard, or by clicking on the "Manage App" button after the deploy step is finished.) On that page, there should be a section called "Config Variables" where you can manage the config vars for your application. You'll need click the "Reveal Config Vars" button to see which variables are available, and then the "Edit" button to allow you to change these variables.
Take the client ID you got from Google, and paste it into the "VALUE" field
next to the GOOGLE_OAUTH_CLIENT_ID field, replacing the dummy value that
was there before. Similarly, take the client secret you got from Google,
and paste it into the "VALUE" field next to the GOOGLE_OAUTH_CLIENT_SECRET
field, replacing the dummy value that was there before.
Click the "Save" button when you're done.
Your app name from Heroku will determine the URL that your app is running on:
the URL will be https://APPNAME.herokuapp.com. For example, if Heroku
assigned you an app name of peaceful-lake, your app will be available at
https://peaceful-lake.herokuapp.com. Visit that URL, and you should
immediately be redirected to login with Google!
If you'd prefer to run this locally on your computer, you can do that as well.
Visit the Google Developers Console at https://console.developers.google.com
and create a new project. In the "APIs & auth" section, click on "Credentials",
and then click the "Create a new Client ID" button. Select "Web Application"
for the application type, and click the "Configure consent screen" button.
Put in your application information, and click Save. Once you’ve done that,
you’ll see two new fields: "Authorized JavaScript origins" and
"Authorized redirect URIs". Set the authorized redirect URI to
http://localhost:5000/login/google/authorized, and click "Create Client ID".
Google will give you a client ID and client secret, which we'll use in step 3.
Run the following commands on your computer:
git clone https://github.com/singingwolfboy/flask-dance-google.git cd flask-dance-google python3 -m venv venv source venv/bin/activate pip install -r requirements.txt
These commands will clone this git repository onto your computer,
create a virtual environment for this project, activate it, and install
the dependencies listed in requirements.txt.
Many applications use environment variables for configuration, and Flask-Dance is no exception. You'll need to set the following environment variables:
FLASK_APP: set this togoogle.pyGOOGLE_OAUTH_CLIENT_ID: set this to the client ID you got from Google.GOOGLE_OAUTH_CLIENT_SECRET: set this to the client secret you got from Google.OAUTHLIB_RELAX_TOKEN_SCOPE: set this totrue. This indicates that it's OK for Google to return different OAuth scopes than requested; Google does that sometimes.OAUTHLIB_INSECURE_TRANSPORT: set this totrue. This indicates that you're doing local testing, and it's OK to use HTTP instead of HTTPS for OAuth. You should only do this for local testing. Do not set this in production! [oauthlib docs]
The easiest way to set these environment variables is to define them in
an .env file. You can then install the python-dotenv package
to make Flask automatically read this file when you run the dev server.
This repository has a .env.example file that you can copy to
.env to get a head start
Run your app using the flask command:
flask run
Then, go to http://localhost:5000/ to visit your app and log in with Google!
If you get an error message that says "Could not locate a Flask application",
then you need to install the python-dotenv package using pip:
pip install python-dotenv
Once the package is installed, try the flask run command again!
Fork this GitHub repo so that you can make changes to it. Read the documentation for Flask and Flask-Dance to learn what's possible. Ask questions, learn as you go, build your own OAuth-enabled web application, and don't forget to be awesome!