Merge pull request #81 from codacy/proxy-support

feat: add proxy support for mcp server CF-2438

Author: nedaKaighobadi

index.ts

@@ -10,6 +10,10 @@ import * as Tools from './src/tools/index.js';
 import type { ToolKeys } from './src/schemas.js';
 import * as Handlers from './src/handlers/index.js';
 import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
+import { applyProxyConfig } from './src/proxy.js';
+
+// Apply proxy / SSL configuration before any outbound requests are made.
+applyProxyConfig();
 
 // Check for API key
 const CODACY_ACCOUNT_TOKEN = process.env.CODACY_ACCOUNT_TOKEN;

package.json

@@ -34,9 +34,8 @@
   "dependencies": {
     "@modelcontextprotocol/sdk": "1.25.2",
     "@types/node": "^22",
-    "@types/node-fetch": "^2.6.12",
     "@types/sarif": "2.1.7",
-    "node-fetch": "^3.3.2",
+    "undici": "^6.0.0",
     "universal-user-agent": "^7.0.2"
   },
   "devDependencies": {

src/proxy.ts

@@ -0,0 +1,83 @@
+import { Agent, ProxyAgent, setGlobalDispatcher } from 'undici';
+import type { Dispatcher } from 'undici';
+
+// Matches a request hostname against the NO_PROXY / no_proxy list.
+// Handles exact matches and suffix matches (e.g. "example.com" also covers "sub.example.com").
+function matchesNoProxy(hostname: string): boolean {
+  const noProxy = process.env.NO_PROXY ?? process.env.no_proxy;
+  if (!noProxy) return false;
+  const lower = hostname.toLowerCase();
+  return noProxy
+    .split(',')
+    .map(h => h.trim().toLowerCase().replace(/^\./, ''))
+    .filter(Boolean)
+    .some(entry => entry === '*' || lower === entry || lower.endsWith('.' + entry));
+}
+
+// Ensures a proxy URL has a protocol prefix. A bare host:port (e.g. "localhost:8080")
+// is treated as HTTP, matching the convention used by curl and most proxy tools.
+function normalizeProxyUrl(url: string): string {
+  return /^https?:\/\//i.test(url) ? url : `http://${url}`;
+}
+
+// Routes each fetch() call through HTTPS_PROXY or HTTP_PROXY based on the request
+// protocol, bypassing the proxy for any host that matches NO_PROXY.
+// Extends Agent so all Dispatcher methods are already implemented.
+class ProxyRoutingDispatcher extends Agent {
+  private readonly _httpsProxy: ProxyAgent | undefined;
+  private readonly _httpProxy: ProxyAgent | undefined;
+
+  constructor(httpProxy: string | undefined, httpsProxy: string | undefined, disableSSL: boolean) {
+    super();
+    // requestTls — TLS to the target server through the CONNECT tunnel.
+    // proxyTls  — TLS to the proxy itself (relevant when proxy URL is HTTPS).
+    const tlsOpts = disableSSL ? { rejectUnauthorized: false } : undefined;
+    const proxyOpts = tlsOpts ? { requestTls: tlsOpts, proxyTls: tlsOpts } : {};
+    this._httpsProxy = httpsProxy
+      ? new ProxyAgent({ uri: normalizeProxyUrl(httpsProxy), ...proxyOpts })
+      : undefined;
+    this._httpProxy = httpProxy
+      ? new ProxyAgent({ uri: normalizeProxyUrl(httpProxy), ...proxyOpts })
+      : undefined;
+  }
+
+  dispatch(options: Dispatcher.DispatchOptions, handler: Dispatcher.DispatchHandlers): boolean {
+    const origin = options.origin instanceof URL ? options.origin : new URL(String(options.origin));
+
+    if (!matchesNoProxy(origin.hostname)) {
+      const proxy =
+        origin.protocol === 'https:'
+          ? (this._httpsProxy ?? this._httpProxy)
+          : (this._httpProxy ?? this._httpsProxy);
+      if (proxy) return proxy.dispatch(options, handler);
+    }
+
+    return super.dispatch(options, handler);
+  }
+}
+
+/**
+ * Reads proxy configuration from environment variables and patches the global
+ * fetch dispatcher used by Node.js native fetch.
+ *
+ * Supported env vars:
+ *   HTTPS_PROXY / https_proxy — proxy for HTTPS requests
+ *   HTTP_PROXY  / http_proxy  — proxy for HTTP requests
+ *   NO_PROXY    / no_proxy    — comma-separated list of hosts to bypass
+ *   NODE_TLS_REJECT_UNAUTHORIZED=0 — disable TLS certificate verification
+ *
+ * For corporate environments that use SSL inspection (MITM proxies), prefer adding the
+ * corporate CA certificate to Node's trust store rather than disabling verification:
+ *   NODE_EXTRA_CA_CERTS=/path/to/corporate-ca.pem
+ * Node reads this at startup and it applies to all TLS connections, including
+ * the inner tunnel established through a CONNECT proxy.
+ */
+export function applyProxyConfig(): void {
+  const httpsProxy = process.env.HTTPS_PROXY ?? process.env.https_proxy;
+  const httpProxy = process.env.HTTP_PROXY ?? process.env.http_proxy;
+
+  if (!httpsProxy && !httpProxy) return;
+
+  const disableSSL = process.env.NODE_TLS_REJECT_UNAUTHORIZED === '0';
+  setGlobalDispatcher(new ProxyRoutingDispatcher(httpProxy, httpsProxy, disableSSL));
+}