add server settings api

apps/ignis-server/server/routes/proxy.js

@@ -1,6 +1,7 @@
 const express = require("express");
 const dns = require("dns").promises;
 const net = require("net");
+const settings = require("../settings");
 
 const router = express.Router();
 
@@ -105,6 +106,19 @@ router.post("/", async (req, res) => {
     return res.status(e.statusCode || 400).json({ error: e.message });
   }
 
+  // When a host allowlist is defined , the proxy only reaches those hosts.
+  const allowlist = settings.get("proxyAllowlist");
+
+  if (allowlist.length > 0) {
+    const host = new URL(url).hostname;
+
+    if (!allowlist.includes(host)) {
+      return res
+        .status(403)
+        .json({ error: `Host not in proxy allowlist: ${host}` });
+    }
+  }
+
   try {
     // Forward the caller's headers as-is.
     const fetchOpts = {