Merge pull request #8681 from backstage/rugvip/assetcache

app-backend: store static assets across deployments and improve caching

.changeset/sixty-laws-laugh.md

@@ -0,0 +1,22 @@
+---
+'@backstage/create-app': patch
+---
+
+Updated the configuration of the `app-backend` plugin to enable the static asset store by passing on `database` from the plugin environment to `createRouter`.
+
+To apply this change to an existing app, make the following change to `packages/backend/src/plugins/app.ts`:
+
+```diff
+ export default async function createPlugin({
+   logger,
+   config,
++  database,
+ }: PluginEnvironment): Promise<Router> {
+   return await createRouter({
+     logger,
+     config,
++    database,
+     appPackageName: 'app',
+   });
+ }
+```

.changeset/wild-pugs-call.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-app-backend': patch
+---
+
+Updated the cache control headers for static assets to instruct clients to cache them for 14 days.

.changeset/witty-avocados-bow.md

@@ -0,0 +1,7 @@
+---
+'@backstage/plugin-app-backend': patch
+---
+
+Added a new asset cache that stores static assets from previous deployments in the database. This fixes an issue where users have old browser tabs open and try to lazy-load static assets that no longer exist in the latest version.
+
+The asset cache is enabled by passing the `database` option to `createRouter`.