Add ability to override client assets : logo - favicon - PWA icons - PWA manifest name and description (#2897)

* Add client-overrides storage to config

* Add static-serve for client overrides

* Move backgroun-image logo from bundle to css tag for runtime content hash

* Add dynamic JSON manifest

* Add content hash for manifest, favicon and logo

Co-authored-by: kimsible <kimsible@users.noreply.github.com>

4 files changed, 83 insertions, 6 deletions

diff --git a/server/controllers/client.ts b/server/controllers/client.ts
index 65b5a053c..88f51907b 100644
--- a/server/controllers/client.ts
+++ b/server/controllers/client.ts
@@ -1,3 +1,4 @@
+import { constants, promises as fs } from 'fs'
 import * as express from 'express'
 import { join } from 'path'
 import { root } from '../helpers/core-utils'
@@ -39,20 +40,40 @@ clientsRouter.use(
 )
 
 // Static HTML/CSS/JS client files
-
 const staticClientFiles = [
-  'manifest.webmanifest',
   'ngsw-worker.js',
   'ngsw.json'
 ]
+
 for (const staticClientFile of staticClientFiles) {
   const path = join(root(), 'client', 'dist', staticClientFile)
 
-  clientsRouter.get('/' + staticClientFile, (req: express.Request, res: express.Response) => {
+  clientsRouter.get(`/${staticClientFile}`, (req: express.Request, res: express.Response) => {
     res.sendFile(path, { maxAge: STATIC_MAX_AGE.SERVER })
   })
 }
 
+// Dynamic PWA manifest
+clientsRouter.get('/manifest.webmanifest', asyncMiddleware(generateManifest))
+
+// Static client overrides
+const staticClientOverrides = [
+  'assets/images/logo.svg',
+  'assets/images/favicon.png',
+  'assets/images/icons/icon-36x36.png',
+  'assets/images/icons/icon-48x48.png',
+  'assets/images/icons/icon-72x72.png',
+  'assets/images/icons/icon-96x96.png',
+  'assets/images/icons/icon-144x144.png',
+  'assets/images/icons/icon-192x192.png',
+  'assets/images/icons/icon-512x512.png'
+]
+
+for (const staticClientOverride of staticClientOverrides) {
+  const overridePhysicalPath = join(CONFIG.STORAGE.CLIENT_OVERRIDES_DIR, staticClientOverride)
+  clientsRouter.use(`/client/${staticClientOverride}`, asyncMiddleware(serveClientOverride(overridePhysicalPath)))
+}
+
 clientsRouter.use('/client/locales/:locale/:file.json', serveServerTranslations)
 clientsRouter.use('/client', express.static(distPath, { maxAge: STATIC_MAX_AGE.CLIENT }))
 
@@ -130,3 +151,28 @@ function sendHTML (html: string, res: express.Response) {
 
   return res.send(html)
 }
+
+async function generateManifest (req: express.Request, res: express.Response) {
+  const manifestPhysicalPath = join(root(), 'client', 'dist', 'manifest.webmanifest')
+  const manifestJson = await fs.readFile(manifestPhysicalPath, 'utf8')
+  const manifest = JSON.parse(manifestJson)
+
+  manifest.name = CONFIG.INSTANCE.NAME
+  manifest.short_name = CONFIG.INSTANCE.NAME
+  manifest.description = CONFIG.INSTANCE.SHORT_DESCRIPTION
+
+  res.json(manifest)
+}
+
+function serveClientOverride (path: string) {
+  return async (req: express.Request, res: express.Response, next: express.NextFunction) => {
+    try {
+      await fs.access(path, constants.F_OK)
+      // Serve override client
+      res.sendFile(path, { maxAge: STATIC_MAX_AGE.SERVER })
+    } catch {
+      // Serve dist client
+      next()
+    }
+  }
+}
diff --git a/server/initializers/config.ts b/server/initializers/config.ts
index 48e2cbc1a..32bd3bbe2 100644
--- a/server/initializers/config.ts
+++ b/server/initializers/config.ts
@@ -68,7 +68,8 @@ const CONFIG = {
     CAPTIONS_DIR: buildPath(config.get<string>('storage.captions')),
     TORRENTS_DIR: buildPath(config.get<string>('storage.torrents')),
     CACHE_DIR: buildPath(config.get<string>('storage.cache')),
-    PLUGINS_DIR: buildPath(config.get<string>('storage.plugins'))
+    PLUGINS_DIR: buildPath(config.get<string>('storage.plugins')),
+    CLIENT_OVERRIDES_DIR: buildPath(config.get<string>('storage.client_overrides'))
   },
   WEBSERVER: {
     SCHEME: config.get<boolean>('webserver.https') === true ? 'https' : 'http',
diff --git a/server/initializers/constants.ts b/server/initializers/constants.ts
index 9a262fd4b..e730e3c84 100644
--- a/server/initializers/constants.ts
+++ b/server/initializers/constants.ts
@@ -1,4 +1,5 @@
 import { join } from 'path'
+import { randomBytes } from 'crypto'
 import { JobType, VideoRateType, VideoResolution, VideoState } from '../../shared/models'
 import { ActivityPubActorType } from '../../shared/models/activitypub'
 import { FollowState } from '../../shared/models/actors'
@@ -710,6 +711,14 @@ registerConfigChangedHandler(() => {
 
 // ---------------------------------------------------------------------------
 
+const FILES_CONTENT_HASH = {
+  MANIFEST: generateContentHash(),
+  FAVICON: generateContentHash(),
+  LOGO: generateContentHash()
+}
+
+// ---------------------------------------------------------------------------
+
 export {
   WEBSERVER,
   API_VERSION,
@@ -792,8 +801,10 @@ export {
   VIDEO_PLAYLIST_PRIVACIES,
   PLUGIN_EXTERNAL_AUTH_TOKEN_LIFETIME,
   ASSETS_PATH,
+  FILES_CONTENT_HASH,
   loadLanguages,
-  buildLanguages
+  buildLanguages,
+  generateContentHash
 }
 
 // ---------------------------------------------------------------------------
@@ -895,3 +906,7 @@ function buildLanguages () {
 
   return languages
 }
+
+function generateContentHash () {
+  return randomBytes(20).toString('hex')
+}
diff --git a/server/lib/client-html.ts b/server/lib/client-html.ts
index 3e6da2898..5996f3c70 100644
--- a/server/lib/client-html.ts
+++ b/server/lib/client-html.ts
@@ -1,6 +1,6 @@
 import * as express from 'express'
 import { buildFileLocale, getDefaultLocale, is18nLocale, POSSIBLE_LOCALES } from '../../shared/models/i18n/i18n'
-import { CUSTOM_HTML_TAG_COMMENTS, EMBED_SIZE, PLUGIN_GLOBAL_CSS_PATH, WEBSERVER } from '../initializers/constants'
+import { CUSTOM_HTML_TAG_COMMENTS, EMBED_SIZE, PLUGIN_GLOBAL_CSS_PATH, WEBSERVER, FILES_CONTENT_HASH } from '../initializers/constants'
 import { join } from 'path'
 import { escapeHTML, sha256 } from '../helpers/core-utils'
 import { VideoModel } from '../models/video/video'
@@ -101,6 +101,9 @@ export class ClientHtml {
     let html = buffer.toString()
 
     if (paramLang) html = ClientHtml.addHtmlLang(html, paramLang)
+    html = ClientHtml.addManifestContentHash(html)
+    html = ClientHtml.addFaviconContentHash(html)
+    html = ClientHtml.addLogoContentHash(html)
     html = ClientHtml.addCustomCSS(html)
     html = await ClientHtml.addAsyncPluginCSS(html)
 
@@ -136,6 +139,18 @@ export class ClientHtml {
     return htmlStringPage.replace('<html>', `<html lang="${paramLang}">`)
   }
 
+  private static addManifestContentHash (htmlStringPage: string) {
+    return htmlStringPage.replace('[manifestContentHash]', FILES_CONTENT_HASH.MANIFEST)
+  }
+
+  private static addFaviconContentHash(htmlStringPage: string) {
+    return htmlStringPage.replace('[faviconContentHash]', FILES_CONTENT_HASH.FAVICON)
+  }
+
+  private static addLogoContentHash(htmlStringPage: string) {
+    return htmlStringPage.replace('[logoContentHash]', FILES_CONTENT_HASH.LOGO)
+  }
+
   private static addTitleTag (htmlStringPage: string, title?: string) {
     let text = title || CONFIG.INSTANCE.NAME
     if (title) text += ` - ${CONFIG.INSTANCE.NAME}`