fix: add dns caching (#3736)

packages/common/src/dns.ts

@@ -0,0 +1,22 @@
+import { DnsCacheManager } from "dns-caching";
+
+import { logger } from "@homarr/log";
+
+// Add global type augmentation for homarr
+declare global {
+  var homarr: {
+    dnsCacheManager?: DnsCacheManager;
+    // add other properties if needed
+  };
+}
+
+// Initialize global.homarr if not present
+// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
+global.homarr ??= {};
+global.homarr.dnsCacheManager ??= new DnsCacheManager({
+  cacheMaxEntries: 1000,
+  forceMinTtl: 5 * 60 * 1000, // 5 minutes
+  logger,
+});
+
+global.homarr.dnsCacheManager.initialize();

packages/common/src/fetch-agent.ts

@@ -3,6 +3,9 @@ import { Agent } from "undici";
 
 import { logger } from "@homarr/log";
 
+// The below import statement initializes dns-caching
+import "./dns";
+
 export class LoggingAgent extends Agent {
   constructor(...props: ConstructorParameters<typeof Agent>) {
     super(...props);