title: Firebase Database, Cloud Functions, Rules
body: <p>How to restrict <code>write</code> access to <code>/lastmodified</code> table in database named <code>/functions-project-12345</code> only to cloud function, <code>read &amp; write</code> access to table <code>/chat</code> to everyone</p>
  
  <pre><code>/functions-project-12345
      /lastmodified: 1234567890
      /chat
          /key-123456
              username: "Mat"
              text: "Hey Bob!"
          /key-123457
              username: "Bob"
              text: "Hey Mat"
  </code></pre>