Merge pull request #1708 from LemmyNet/cache-control

Cache static data for a day

src/server/index.tsx

@@ -20,7 +20,13 @@ const [hostname, port] = process.env["LEMMY_UI_HOST"]
 
 server.use(express.json());
 server.use(express.urlencoded({ extended: false }));
-server.use(getStaticDir(), express.static(path.resolve("./dist")));
+server.use(
+  getStaticDir(),
+  express.static(path.resolve("./dist"), {
+    maxAge: 24 * 60 * 60 * 1000, // 1 day
+    immutable: true,
+  })
+);
 server.use(setCacheControl);
 
 if (!process.env["LEMMY_UI_DISABLE_CSP"] && !process.env["LEMMY_UI_DEBUG"]) {

src/server/middleware.ts

@@ -1,4 +1,4 @@
-import type { NextFunction, Response } from "express";
+import type { NextFunction, Request, Response } from "express";
 import { UserService } from "../shared/services";
 
 export function setDefaultCsp({
@@ -18,24 +18,32 @@ export function setDefaultCsp({
 
 // Set cache-control headers. If user is logged in, set `private` to prevent storing data in
 // shared caches (eg nginx) and leaking of private data. If user is not logged in, allow caching
-// all responses for 60 seconds to reduce load on backend and database. The specific cache
+// all responses for 5 seconds to reduce load on backend and database. The specific cache
 // interval is rather arbitrary and could be set higher (less server load) or lower (fresher data).
 //
 // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control
-export function setCacheControl({
-  res,
-  next,
-}: {
-  res: Response;
-  next: NextFunction;
-}) {
+export function setCacheControl(
+  req: Request,
+  res: Response,
+  next: NextFunction
+) {
   const user = UserService.Instance;
   let caching: string;
+
+  if (
+    req.path.match(/\.(js|css|txt|manifest\.webmanifest)\/?$/) ||
+    req.path.includes("/css/themelist")
+  ) {
+    // Static content gets cached publicly for a day
+    caching = "public, max-age=86400";
+  } else {
     if (user.auth()) {
       caching = "private";
     } else {
-    caching = "public, max-age=60";
+      caching = "public, max-age=5";
     }
+  }
+
   res.setHeader("Cache-Control", caching);
 
   next();

src/server/utils/create-ssr-html.tsx

@@ -24,7 +24,7 @@ export async function createSsrHtml(
 
   if (!appleTouchIcon) {
     appleTouchIcon = site?.site_view.site.icon
-      ? `data:image/png;base64,${sharp(
+      ? `data:image/png;base64,${await sharp(
           await fetchIconPng(site.site_view.site.icon)
         )
           .resize(180, 180)