add login with google

app/auth/__init__.py

@@ -7,4 +7,5 @@ from .views import (
     reset_password,
     forgot_password,
     github,
+    google,
 )

app/auth/templates/auth/login.html

@@ -78,6 +78,10 @@
           <a href="{{ url_for('auth.github_login') }}" class="btn btn-block btn-social btn-github">
             <i class="fa fa-github"></i> Sign in with Github
           </a>
+
+          <a href="{{ url_for('auth.google_login') }}" class="btn btn-block btn-social btn-google">
+            <i class="fa fa-google"></i> Sign in with Google
+          </a>
       </div>
     </div>
 

app/auth/templates/auth/register.html

@@ -67,6 +67,11 @@
           <a href="{{ url_for('auth.github_login') }}" class="btn btn-block btn-social btn-github">
             <i class="fa fa-github"></i> Sign up with Github
           </a>
+
+          <a href="{{ url_for('auth.google_login') }}" class="btn btn-block btn-social btn-google">
+            <i class="fa fa-google"></i> Sign up with Google
+          </a>
+        </div>
       </div>
     </div>
   </div>

app/auth/views/google.py

@@ -0,0 +1,127 @@
+import arrow
+from flask import request, session, redirect, url_for, flash
+from flask_login import login_user
+from requests_oauthlib import OAuth2Session
+
+from app import s3
+from app.auth.base import auth_bp
+from app.config import URL, GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET
+from app.email_utils import notify_admin
+from app.extensions import db
+from app.log import LOG
+from app.models import User, File
+from app.utils import random_string
+
+authorization_base_url = "https://accounts.google.com/o/oauth2/v2/auth"
+token_url = "https://www.googleapis.com/oauth2/v4/token"
+
+scope = [
+    "https://www.googleapis.com/auth/userinfo.email",
+    "https://www.googleapis.com/auth/userinfo.profile",
+    "openid",
+]
+
+# need to set explicitly redirect_uri instead of leaving the lib to pre-fill redirect_uri
+# when served behind nginx, the redirect_uri is localhost... and not the real url
+redirect_uri = URL + "/auth/google/callback"
+
+
+@auth_bp.route("/google/login")
+def google_login():
+    # to avoid flask-login displaying the login error message
+    session.pop("_flashes", None)
+
+    google = OAuth2Session(GOOGLE_CLIENT_ID, scope=scope, redirect_uri=redirect_uri)
+    authorization_url, state = google.authorization_url(authorization_base_url)
+
+    # State is used to prevent CSRF, keep this for later.
+    session["oauth_state"] = state
+    return redirect(authorization_url)
+
+
+@auth_bp.route("/google/callback")
+def google_callback():
+    google = OAuth2Session(
+        GOOGLE_CLIENT_ID,
+        state=session["oauth_state"],
+        scope=scope,
+        redirect_uri=redirect_uri,
+    )
+    token = google.fetch_token(
+        token_url,
+        client_secret=GOOGLE_CLIENT_SECRET,
+        authorization_response=request.url,
+    )
+
+    # Fetch a protected resource, i.e. user profile
+    # {
+    #     "email": "abcd@gmail.com",
+    #     "family_name": "First name",
+    #     "given_name": "Last name",
+    #     "id": "1234",
+    #     "locale": "en",
+    #     "name": "First Last",
+    #     "picture": "http://profile.jpg",
+    #     "verified_email": true
+    # }
+    google_user_data = google.get(
+        "https://www.googleapis.com/oauth2/v1/userinfo"
+    ).json()
+
+    email = google_user_data["email"]
+    user = User.get_by(email=email)
+
+    picture_url = google_user_data.get("picture")
+
+    if user:
+        if picture_url and not user.profile_picture_id:
+            LOG.d("set user profile picture to %s", picture_url)
+            file = create_file_from_url(picture_url)
+            user.profile_picture_id = file.id
+            db.session.commit()
+
+        login_user(user)
+    # create user
+    else:
+        LOG.d("create google user with %s", google_user_data)
+        user = User.create(email=email, name=google_user_data["name"])
+
+        # set a random password
+        user.set_password(random_string(20))
+
+        user.activated = True
+
+        if picture_url:
+            LOG.d("set user profile picture to %s", picture_url)
+            file = create_file_from_url(picture_url)
+            user.profile_picture_id = file.id
+
+        db.session.commit()
+        login_user(user)
+
+        flash(f"Welcome to SimpleLogin {user.name}!", "success")
+
+        notify_admin(
+            f"new user signs up {user.email}", f"{user.name} signs up at {arrow.now()}"
+        )
+
+    # The activation link contains the original page, for ex authorize page
+    if "next" in request.args:
+        next_url = request.args.get("next")
+        LOG.debug("redirect user to %s", next_url)
+        return redirect(next_url)
+    else:
+        LOG.debug("redirect user to dashboard")
+        return redirect(url_for("dashboard.index"))
+
+
+def create_file_from_url(url) -> File:
+    file_path = random_string(30)
+    file = File.create(path=file_path)
+
+    s3.upload_from_url(url, file_path)
+
+    db.session.flush()
+    LOG.d("upload file %s to s3", file)
+
+    return file

app/s3.py

@@ -1,6 +1,7 @@
 from io import BytesIO
 
 import boto3
+import requests
 
 from app.config import AWS_REGION, BUCKET, AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY
 
@@ -18,6 +19,11 @@ def upload_from_bytesio(key: str, bs: BytesIO, content_type="string") -> None:
     )
 
 
+def upload_from_url(url: str, upload_path):
+    r = requests.get(url)
+    upload_from_bytesio(upload_path, BytesIO(r.content))
+
+
 def delete_file(key: str) -> None:
     o = session.resource("s3").Bucket(BUCKET).Object(key)
     o.delete()