build: check all relevant environment variables are set on start up

public/index.html

@@ -57,7 +57,7 @@
         <div class="container">
             <h2>Get Started</h2>
             <p>Ready to take the next step in your IT career? Apply today!</p>
-            <form id="applicationForm">
+            <form id="applicationForm" method="post" action="https://mailer.melonion.me/subscription/form">
                 <input type="hidden" name="list_id" value="3">
                 <input type="text" name="name" placeholder="Your Name" required>
                 <input type="email" name="email" placeholder="Your Email" required>

server.js

@@ -2,9 +2,12 @@ import express from 'express';
 import dotenv from 'dotenv';
 import path from 'path'; // Import the path module
 import routes from './src/routes.js'; // Import routes from routes.js
+import { validateEnvVariables } from './src/envValidator.js';
 
 dotenv.config();
 
+validateEnvVariables();
+
 const app = express();
 const PORT = process.env.PORT || 3002;
 

src/envValidator.js

@@ -0,0 +1,16 @@
+export function validateEnvVariables() {
+    const requiredVars = [
+        'LISTMONK_URL',
+        'LISTMONK_USERNAME',
+        'LISTMONK_PASSWORD',
+        'LIST_ID'
+    ];
+
+    const missingVars = requiredVars.filter((variable) => !process.env[variable]);
+
+    if (missingVars.length > 0) {
+        console.error(`Error: Missing environment variables: ${missingVars.join(', ')}`);
+        process.exit(1); // Exit the application with a failure code
+    }
+    console.log('All required environment variables are set.');
+}