3 files changed, 85 insertions, 20 deletions

diff --git a/server/controllers/index.ts b/server/controllers/index.ts
index 8b3501712..0d64b33bb 100644
--- a/server/controllers/index.ts
+++ b/server/controllers/index.ts
@@ -4,6 +4,7 @@ export * from './client'
 export * from './feeds'
 export * from './services'
 export * from './static'
+export * from './lazy-static'
 export * from './webfinger'
 export * from './tracker'
 export * from './bots'
diff --git a/server/controllers/lazy-static.ts b/server/controllers/lazy-static.ts
new file mode 100644
index 000000000..4285fd727
--- /dev/null
+++ b/server/controllers/lazy-static.ts
@@ -0,0 +1,80 @@
+import * as cors from 'cors'
+import * as express from 'express'
+import { LAZY_STATIC_PATHS, STATIC_MAX_AGE } from '../initializers/constants'
+import { VideosCaptionCache, VideosPreviewCache } from '../lib/files-cache'
+import { asyncMiddleware } from '../middlewares'
+import { AvatarModel } from '../models/avatar/avatar'
+import { logger } from '../helpers/logger'
+import { avatarPathUnsafeCache, pushAvatarProcessInQueue } from '../lib/avatar'
+
+const lazyStaticRouter = express.Router()
+
+lazyStaticRouter.use(cors())
+
+lazyStaticRouter.use(
+  LAZY_STATIC_PATHS.AVATARS + ':filename',
+  asyncMiddleware(getAvatar)
+)
+
+lazyStaticRouter.use(
+  LAZY_STATIC_PATHS.PREVIEWS + ':uuid.jpg',
+  asyncMiddleware(getPreview)
+)
+
+lazyStaticRouter.use(
+  LAZY_STATIC_PATHS.VIDEO_CAPTIONS + ':videoId-:captionLanguage([a-z]+).vtt',
+  asyncMiddleware(getVideoCaption)
+)
+
+// ---------------------------------------------------------------------------
+
+export {
+  lazyStaticRouter,
+  getPreview,
+  getVideoCaption
+}
+
+// ---------------------------------------------------------------------------
+
+async function getAvatar (req: express.Request, res: express.Response) {
+  const filename = req.params.filename
+
+  if (avatarPathUnsafeCache.has(filename)) {
+    return res.sendFile(avatarPathUnsafeCache.get(filename), { maxAge: STATIC_MAX_AGE.SERVER })
+  }
+
+  const avatar = await AvatarModel.loadByName(filename)
+  if (avatar.onDisk === false) {
+    if (!avatar.fileUrl) return res.sendStatus(404)
+
+    logger.info('Lazy serve remote avatar image %s.', avatar.fileUrl)
+
+    await pushAvatarProcessInQueue({ filename: avatar.filename, fileUrl: avatar.fileUrl })
+
+    avatar.onDisk = true
+    avatar.save()
+      .catch(err => logger.error('Cannot save new avatar disk state.', { err }))
+  }
+
+  const path = avatar.getPath()
+
+  avatarPathUnsafeCache.set(filename, path)
+  return res.sendFile(path, { maxAge: STATIC_MAX_AGE.SERVER })
+}
+
+async function getPreview (req: express.Request, res: express.Response) {
+  const result = await VideosPreviewCache.Instance.getFilePath(req.params.uuid)
+  if (!result) return res.sendStatus(404)
+
+  return res.sendFile(result.path, { maxAge: STATIC_MAX_AGE.SERVER })
+}
+
+async function getVideoCaption (req: express.Request, res: express.Response) {
+  const result = await VideosCaptionCache.Instance.getFilePath({
+    videoId: req.params.videoId,
+    language: req.params.captionLanguage
+  })
+  if (!result) return res.sendStatus(404)
+
+  return res.sendFile(result.path, { maxAge: STATIC_MAX_AGE.SERVER })
+}
diff --git a/server/controllers/static.ts b/server/controllers/static.ts
index 110d25031..8979ef5f3 100644
--- a/server/controllers/static.ts
+++ b/server/controllers/static.ts
@@ -9,7 +9,6 @@ import {
   STATIC_PATHS,
   WEBSERVER
 } from '../initializers/constants'
-import { VideosCaptionCache, VideosPreviewCache } from '../lib/files-cache'
 import { cacheRoute } from '../middlewares/cache'
 import { asyncMiddleware, videosGetValidator } from '../middlewares'
 import { VideoModel } from '../models/video/video'
@@ -19,6 +18,7 @@ import { HttpNodeinfoDiasporaSoftwareNsSchema20 } from '../../shared/models/node
 import { join } from 'path'
 import { root } from '../helpers/core-utils'
 import { CONFIG } from '../initializers/config'
+import { getPreview, getVideoCaption } from './lazy-static'
 
 const staticRouter = express.Router()
 
@@ -72,19 +72,20 @@ staticRouter.use(
   express.static(thumbnailsPhysicalPath, { maxAge: STATIC_MAX_AGE.SERVER, fallthrough: false }) // 404 if the file does not exist
 )
 
+// DEPRECATED: use lazy-static route instead
 const avatarsPhysicalPath = CONFIG.STORAGE.AVATARS_DIR
 staticRouter.use(
   STATIC_PATHS.AVATARS,
   express.static(avatarsPhysicalPath, { maxAge: STATIC_MAX_AGE.SERVER, fallthrough: false }) // 404 if the file does not exist
 )
 
-// We don't have video previews, fetch them from the origin instance
+// DEPRECATED: use lazy-static route instead
 staticRouter.use(
   STATIC_PATHS.PREVIEWS + ':uuid.jpg',
   asyncMiddleware(getPreview)
 )
 
-// We don't have video captions, fetch them from the origin instance
+// DEPRECATED: use lazy-static route instead
 staticRouter.use(
   STATIC_PATHS.VIDEO_CAPTIONS + ':videoId-:captionLanguage([a-z]+).vtt',
   asyncMiddleware(getVideoCaption)
@@ -177,23 +178,6 @@ export {
 
 // ---------------------------------------------------------------------------
 
-async function getPreview (req: express.Request, res: express.Response) {
-  const result = await VideosPreviewCache.Instance.getFilePath(req.params.uuid)
-  if (!result) return res.sendStatus(404)
-
-  return res.sendFile(result.path, { maxAge: STATIC_MAX_AGE })
-}
-
-async function getVideoCaption (req: express.Request, res: express.Response) {
-  const result = await VideosCaptionCache.Instance.getFilePath({
-    videoId: req.params.videoId,
-    language: req.params.captionLanguage
-  })
-  if (!result) return res.sendStatus(404)
-
-  return res.sendFile(result.path, { maxAge: STATIC_MAX_AGE })
-}
-
 async function generateNodeinfo (req: express.Request, res: express.Response) {
   const { totalVideos } = await VideoModel.getStats()
   const { totalLocalVideoComments } = await VideoCommentModel.getStats()