adding basic login feature

config.env.template

 FLASK_APP=app/__init__.py
 FLASK_RUN_HOST=0.0.0.0
 FLASK_DEBUG=1
+SITE_PASSWORD=
+SECRET_KEY=
 
 # Solr variables
 # Hostname for Solr

web/app/__init__.py

 # https://www.digitalocean.com/community/tutorials/how-to-add-authentication-to-your-app-with-flask-login
 # Config stuff adapted from https://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-iii-web-forms
 
-from flask import Flask
+from flask import Flask, session
 from flask_moment import Moment
 import os
 
 def create_app():
     app = Flask(__name__)
 
+    # get the secret key so sessions work
+    secret = os.getenv('SECRET_KEY')
+    app.secret_key = secret
+
     moment.init_app(app)
 
     # blueprint for main parts of app (contents and frontmatter)

web/app/main.py

 # @purpose: Main route for index page, contents, frontmatter, and other miscellaneous pages
 # @acknowledgements:
 # https://www.digitalocean.com/community/tutorials/how-to-add-authentication-to-your-app-with-flask-login
+# https://www.reddit.com/r/flask/comments/k1bvw4/password_protect_pages/
 
-from flask import Blueprint, render_template
+from flask import Blueprint, render_template, session, request, redirect, url_for, flash
 import markdown
+import os
+from functools import wraps
 
 main = Blueprint('main', __name__)
 
+site_password = os.getenv('SITE_PASSWORD')
+
+# custom decorator to check password
+def check_pw(func):
+    @wraps(func)
+    def decorated_function(*args, **kwargs):
+        status = session.get('status')
+        if status != "good":
+            return redirect(url_for('main.login'))
+        return func(*args, **kwargs)
+
+    return decorated_function
+
 # route for index page
 @main.route('/')
+@check_pw
 def index():
     return render_template('index.html')
 
+# route for site login page
+@main.route('/login', methods=['GET','POST'])
+def login():
+    if request.method == "POST":
+        req = request.form
+        password = req.get("password")
+    
+        if password != site_password:
+            flash('wrong password! try again...')
+            return redirect(request.url)
+        
+        session["status"] = 'good'
+        return redirect(url_for("main.index"))
+
+    return render_template('login.html')
+
 # route for table of contents page
 @main.route('/contents/')
 def contents():

web/app/templates/login.html

+{% extends "base.html" %}
+
+{% block content %}
+   
+<form action="/login" method="post">
+  <strong>Password:</strong><br>
+  <input  name='password' ><br><br>
+<input  type="submit" value="Login">
+</form>
+
+{% endblock %}
+
+{% block footer %}
+<footer class="footer p-3">
+  <div class="container info" style="display: none" >
+      <span class="text-muted">© 2023 Julien McHardy & Kat Jungnickel, chapters by respective authors. Licensed under a <a href="http://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)</a> license.</span>
+      <span class="text-muted">Data from the <a href="https://www.politicsofpatents.org/">Politics of Patents</a> research project hosted at Goldsmiths, University of London, and funded by the European Research Council under the European Union’s Horizon 2020 research and innovation programme (#819458).</span>
+   </div>
+</footer>
+{% endblock%}