Add backend boilerplate

src/backend.mjs

@@ -0,0 +1,43 @@
+import express from 'express';
+
+/**
+ * Get Zammad access credentials and verify the connection.
+ * @param {ReturnType<express>} app
+ */
+function initializeZammad(app) {
+  console.info('Checking connection to Zammad...');
+
+  let url = process.env.ZAMMAD_URL || '';
+  if (url === '') {
+    throw new Error(
+      'Could not find the Zammad URL to connect to. Make sure it is provided using the ZAMMAD_URL environment variable. It should point to the root URL of the Zammad installation.'
+    );
+  }
+  url = url.replace(/\/$/, '');
+
+  const token = process.env.ZAMMAD_TOKEN || '';
+  if (token === '') {
+    throw new Error(
+      'Could not find authentication credentials for Zammad. Make sure the token is provided using the ZAMMAD_TOKEN environment variable.'
+    );
+  }
+
+  app.set('zammad url', url);
+  app.set('zammad token', token);
+
+  // TODO Verify the connection
+}
+
+function run() {
+  const app = express();
+
+  initializeZammad(app);
+
+  app.post('/kontakt', (req, res) => {});
+
+  const port = parseInt(process.env.LISTEN_PORT || '3000');
+  return app.listen(port, () => {
+    console.log(`Server listening at http://localhost:${port}...`);
+  });
+}
+run();