From 2322ab7c8356ee8d06adb293a78f4ee20400b21c Mon Sep 17 00:00:00 2001
From: Matthew Raymer <matthew.raymer@anomalist.design>
Date: Thu, 28 Sep 2023 04:32:53 -0400
Subject: [PATCH] WIP: building up VAPID and subscription

---
 .gitignore       |  1 +
 Dockerfile       | 41 +++++++++++++++++++++
 app.py           | 95 ++++++++++++++++++++++++++++++++++++++++++++++++
 build.sh         |  3 ++
 init_db.py       |  9 +++++
 models.py        | 16 ++++++++
 requirements.txt |  4 ++
 7 files changed, 169 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Dockerfile
 create mode 100644 app.py
 create mode 100755 build.sh
 create mode 100644 init_db.py
 create mode 100644 models.py
 create mode 100644 requirements.txt

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b25c15b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+*~
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..d9b832d
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,41 @@
+# Use an official Python runtime as a parent image
+FROM python:3.8-alpine3.18 as builder
+
+RUN apk update && apk upgrade
+RUN apk add --no-cache --virtual .build-deps build-base git
+RUN apk add bash libffi-dev tzdata --upgrade --no-cache
+
+ENV TZ America/New_York
+
+# Set the working directory in the container to /app
+WORKDIR /app
+
+# Copy the current directory contents into the container at /app
+COPY app.py /app
+COPY requirements.txt /app
+COPY models.py /app
+COPY init_db.py /app/init_db.py
+
+
+# Install any needed packages specified in requirements.txt
+RUN pip install --no-cache-dir -r requirements.txt
+RUN python /app/init_db.py
+
+RUN apk del .build-deps
+
+# ---- Production Stage ----
+FROM python:3.8-alpine3.18 as production
+
+# Create a user to run our application
+RUN adduser -D myuser
+
+# Copy the dependencies and installed packages from the builder image
+WORKDIR /app
+COPY --from=builder /app /app
+COPY --from=builder /usr/local /usr/local
+
+# Switch to the created user
+USER myuser
+
+# Start gunicorn with the appropriate options
+CMD ["gunicorn", "-b", "0.0.0.0:5000", "--workers=3", "app:app"]
diff --git a/app.py b/app.py
new file mode 100644
index 0000000..e78ffab
--- /dev/null
+++ b/app.py
@@ -0,0 +1,95 @@
+from flask import Flask, request, jsonify
+from models import db, VAPIDKey, Subscription
+from py_vapid import Vapid
+from pywebpush import webpush, WebPushException
+
+import json
+import os
+
+app = Flask(__name__)
+app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///webpush.db'
+db.init_app(app)
+
+def generate_and_save_vapid_keys():
+    vapid = Vapid()
+    vapid.generate_keys()
+    private_key = vapid.get_private_key().to_pem().decode('utf-8').strip()
+    public_key = vapid.get_public_key().to_pem().decode('utf-8').strip()
+
+    key = VAPIDKey(public_key=public_key, private_key=private_key)
+    db.session.add(key)
+    db.session.commit()
+
+    
+@app.before_first_request
+def initialize():
+    if not VAPIDKey.query.first():
+        generate_and_save_vapid_keys()
+    
+def send_push_notification(subscription_info, message, vapid_key):
+    try:
+        webpush(
+            subscription_info=subscription_info,
+            data=json.dumps(message),
+            vapid_private_key=vapid_key.private_key,
+            vapid_claims={
+                "sub": "mailto:your-email@example.com"
+            }
+        )
+    except WebPushException as e:
+        print(f"Failed to send notification: {e}")
+
+        
+@app.route('/web-push/vapid', methods=['GET'])
+def get_vapid():
+    key = VAPIDKey.query.first()
+    if key:
+        return jsonify(public_key=key.public_key)
+    return jsonify(error='No VAPID keys found'), 404
+
+
+@app.route('/web-push/subscribe', methods=['POST'])
+def subscribe():
+    content = request.json
+    vapid_key = VAPIDKey.query.first()
+    
+    if not vapid_key:
+        return jsonify(success=False, error="No VAPID keys available"), 500
+
+    subscription = Subscription(endpoint=content['endpoint'],
+                                p256dh=content['keys']['p256dh'],
+                                auth=content['keys']['auth'],
+                                vapid_key_id=vapid_key.id)
+    db.session.add(subscription)
+    db.session.commit()
+
+    subscription_info = {
+        "endpoint": subscription.endpoint,
+        "keys": {
+            "p256dh": subscription.p256dh,
+            "auth": subscription.auth
+        }
+    }
+
+    message = {"title": "Subscription Successful", "body": "Thank you for subscribing!"}
+    send_push_notification(subscription_info, message, vapid_key)
+
+    return jsonify(success=True)
+
+
+@app.route('/web-push/unsubscribe', methods=['DELETE'])
+def unsubscribe():
+    content = request.json
+    endpoint = content['endpoint']
+    subscription = Subscription.query.filter_by(endpoint=endpoint).first()
+
+    if subscription:
+        db.session.delete(subscription)
+        db.session.commit()
+        return jsonify(success=True, message="Subscription deleted successfully")
+    else:
+        return jsonify(success=False, error="Subscription not found"), 404
+
+    
+if __name__ == '__main__':
+    app.run(debug=True)
diff --git a/build.sh b/build.sh
new file mode 100755
index 0000000..5a76bba
--- /dev/null
+++ b/build.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+docker build . -t endorser-push-server:1.0 --no-cache
diff --git a/init_db.py b/init_db.py
new file mode 100644
index 0000000..e0ad264
--- /dev/null
+++ b/init_db.py
@@ -0,0 +1,9 @@
+from models import db
+from flask import Flask
+
+app = Flask(__name__)
+app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///webpush.db'
+db.init_app(app)
+
+with app.app_context():
+    db.create_all()
diff --git a/models.py b/models.py
new file mode 100644
index 0000000..eee5197
--- /dev/null
+++ b/models.py
@@ -0,0 +1,16 @@
+from flask_sqlalchemy import SQLAlchemy
+
+db = SQLAlchemy()
+
+class VAPIDKey(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    public_key = db.Column(db.String(255), nullable=False)
+    private_key = db.Column(db.String(255), nullable=False)
+    subscriptions = db.relationship('Subscription', backref='vapid_key', lazy=True)
+
+class Subscription(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    endpoint = db.Column(db.String(500), nullable=False)
+    p256dh = db.Column(db.String(255), nullable=False)
+    auth = db.Column(db.String(255), nullable=False)
+    vapid_key_id = db.Column(db.Integer, db.ForeignKey('vapid_key.id'), nullable=False)
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..a60a779
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,4 @@
+flask
+flask_sqlalchemy
+py_vapid
+pywebpush