Merge pull request #6335 from backstage/iameap/techdocs-cache

[TechDocs] Optional static resource caching

.changeset/techdocs-satisfied-you-blinked.md

@@ -0,0 +1,7 @@
+---
+'@backstage/techdocs-common': minor
+'@backstage/plugin-techdocs-backend': minor
+---
+
+Added the ability for the TechDocs Backend to (optionally) leverage a cache
+store to improve performance when reading files from a cloud storage provider.

.changeset/the-renegade-feeling.md

@@ -0,0 +1,42 @@
+---
+'@backstage/create-app': patch
+---
+
+TechDocs Backend may now (optionally) leverage a cache store to improve
+performance when reading content from a cloud storage provider.
+
+To apply this change to an existing app, pass the cache manager from the plugin
+environment to the `createRouter` function in your backend:
+
+```diff
+// packages/backend/src/plugins/techdocs.ts
+
+export default async function createPlugin({
+  logger,
+  config,
+  discovery,
+  reader,
++  cache,
+}: PluginEnvironment): Promise<Router> {
+
+  // ...
+
+  return await createRouter({
+    preparers,
+    generators,
+    publisher,
+    logger,
+    config,
+    discovery,
++    cache,
+  });
+```
+
+If your `PluginEnvironment` does not include a cache manager, be sure you've
+applied [the cache management change][cm-change] to your backend as well.
+
+[Additional configuration][td-rec-arch] is required if you wish to enable
+caching in TechDocs.
+
+[cm-change]: https://github.com/backstage/backstage/blob/master/packages/create-app/CHANGELOG.md#patch-changes-6
+[td-rec-arch]: https://backstage.io/docs/features/techdocs/architecture#recommended-deployment