Add wallet tracker

wallet-tracker/src/main.js

@@ -0,0 +1,24 @@
+const express = require('express');
+const { createMetrics } = require('./metrics');
+const { loadWalletBalance, loadUSDCBalance, extractWalletBalance, extractUSDCBalance } = require('./solana');
+
+const WALLET_ADDRESS = process.env.WALLET_ADDRESS;
+const [registry, usdcBalanceMetric, solBalanceMetric] = createMetrics();
+const app = express();
+
+app.get('/metrics', async (req, res) => {
+    res.setHeader('Content-Type', registry.contentType);
+
+    let [solBalance, usdcBalance] = await Promise.all([
+        loadWalletBalance(WALLET_ADDRESS),
+        loadUSDCBalance(WALLET_ADDRESS)]);
+
+    solBalanceMetric.set(extractWalletBalance(solBalance));
+    usdcBalanceMetric.set(extractUSDCBalance(usdcBalance));
+
+    res.send(await registry.metrics());
+});
+
+app.listen(3000, () => {
+    console.log("Server is running on port 3000");
+});