Enhancement: Cache and reuse keep-alive HTTP(S) agents (#6536)

src/utils/proxy/http.js

@@ -224,23 +224,43 @@ function homepageDNSLookupFn() {
   };
 }
 
+const homepageLookup = homepageDNSLookupFn();
+const agentCache = new Map();
+
+function getAgent(protocol, disableIpv6) {
+  const cacheKey = `${protocol}:${disableIpv6 ? "ipv4" : "auto"}`;
+  const cachedAgent = agentCache.get(cacheKey);
+  if (cachedAgent) {
+    return cachedAgent;
+  }
+
+  const agentOptions = {
+    keepAlive: true,
+    ...(disableIpv6 ? { family: 4, autoSelectFamily: false } : { autoSelectFamilyAttemptTimeout: 500 }),
+    lookup: homepageLookup,
+  };
+
+  const agent =
+    protocol === "https:"
+      ? new https.Agent({ ...agentOptions, rejectUnauthorized: false })
+      : new http.Agent(agentOptions);
+
+  agentCache.set(cacheKey, agent);
+  return agent;
+}
+
 export async function httpProxy(url, params = {}) {
   const constructedUrl = new URL(url);
   const disableIpv6 = process.env.HOMEPAGE_PROXY_DISABLE_IPV6 === "true";
-  const agentOptions = {
-    ...(disableIpv6 ? { family: 4, autoSelectFamily: false } : { autoSelectFamilyAttemptTimeout: 500 }),
-    lookup: homepageDNSLookupFn(),
-  };
-
   let request = null;
   if (constructedUrl.protocol === "https:") {
     request = httpsRequest(constructedUrl, {
-      agent: new https.Agent({ ...agentOptions, rejectUnauthorized: false }),
+      agent: getAgent(constructedUrl.protocol, disableIpv6),
       ...params,
     });
   } else {
     request = httpRequest(constructedUrl, {
-      agent: new http.Agent(agentOptions),
+      agent: getAgent(constructedUrl.protocol, disableIpv6),
       ...params,
     });
   }