flask_authlib_google_oauth2_login_with_session.py

1from flask import Flask, url_for, session, redirect
2from authlib.integraions.flask_client import OAuth
3
4app = Flask(__name__)
5app.secret_key = '!secret'
6app.config.from_object('config')
7
8oauth = OAuth(app)
9oauth.register(
10    name='google',
11    server_metadata_url='https://accounts.google.com/.well-known/openid-configuration',
12    client_kwargs={
13        'scope': 'openid email profile'
14    }
15)
16
17@app.route('/')
18def homepage():
19    user = session.get('user')
20    if user:
21        return f'Hello, {user["name"]}'
22    return '<a href="/login">Login with Google</a>'
23
24@app.route('/login')
25def login():
26    redirect_uri = url_for('auth', _external=True)
27    return oauth.google.authorize_redirect(redirect_uri)
28
29@app.route('/auth')
30def auth():
31    token = oauth.google.authorize_access_token()
32    user = token.get('userinfo')
33    if user:
34        session['user'] = user
35    return redirect('/')
36
37@app.route('/logout')
38def logout():
39    session.pop('user', None)
40    return redirect('/')
41
42if __name__ == '__main__':
43    app.run(debug=True)