fix: add dns caching (#3736)

packages/common/package.json

@@ -8,6 +8,7 @@
     ".": "./index.ts",
     "./types": "./src/types.ts",
     "./server": "./src/server.ts",
+    "./init-dns": "./src/dns.ts",
     "./client": "./src/client.ts",
     "./env": "./env.ts"
   },
@@ -30,6 +31,7 @@
     "@homarr/log": "workspace:^0.1.0",
     "@paralleldrive/cuid2": "^2.2.2",
     "dayjs": "^1.11.15",
+    "dns-caching": "^0.2.5",
     "next": "15.5.2",
     "react": "19.1.1",
     "react-dom": "19.1.1",

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);