Read the cache keys to be updated from a ts file

TS file is easier to manipulate than a json one: it can be
simply imported, no need of reading from a file and parsing;
and it accepts comments.

__tests__/cache-worker.ts

@@ -74,17 +74,16 @@ beforeEach(async () => {
 
 describe('Update-cache worker', () => {
   test('successfully calls _cacheKeys and _updateCache', async () => {
-    await worker.updateCache('all')
+    await worker.updateCache([...mockKeysValues.keys()])
     expect(worker.errLog).toEqual([])
-    expect(worker.okLog.length).toEqual(3) // Three rounds are needed to update 25 keys, 10 each time
   })
   test('does not fail if _updateCache does not work', async () => {
     global.server.use(
       serloApi.mutation('_updateCache', () => {
         throw new Error('Something went wrong at _updateCache, but be cool')
       })
     )
-    await worker.updateCache('all')
+    await worker.updateCache([...mockKeysValues.keys()])
     expect(worker.errLog[0].message).toContain(
       'Something went wrong at _updateCache, but be cool'
     )
@@ -107,21 +106,27 @@ describe('Update-cache worker', () => {
         )
       })
     )
-    await worker.updateCache('all')
+    await worker.updateCache([...mockKeysValues.keys()])
     expect(worker.errLog[0].message).toContain(
       'Something went wrong while updating value of "de.serlo.org/api/key20", but keep calm'
     )
   })
   test('successfully updates only some values', async () => {
-    await worker.updateCache(
-      'de.serlo.org/api/key0,de.serlo.org/api/key7,de.serlo.org/api/key10,de.serlo.org/api/key20'
-    )
+    await worker.updateCache([
+      'de.serlo.org/api/key0',
+      'de.serlo.org/api/key7',
+      'de.serlo.org/api/key10',
+      'de.serlo.org/api/key20',
+    ])
     expect(worker.errLog).toEqual([])
   })
   test('does not crash even though it had a problem with some values', async () => {
-    await worker.updateCache(
-      'de.serlo.org/api/key0,de.serlo.org/api/keyInexistent,de.serlo.org/api/key10,de.serlo.org/api/keyWrong'
-    )
+    await worker.updateCache([
+      'de.serlo.org/api/key0',
+      'de.serlo.org/api/keyInexistent',
+      'de.serlo.org/api/key10',
+      'de.serlo.org/api/keyWrong',
+    ])
     expect(worker.errLog).not.toEqual([])
   })
 })

cache-worker/Dockerfile

@@ -14,10 +14,10 @@ RUN yarn --frozen-lockfile --production=true --silent
 FROM dev-dependencies as build
 COPY src src
 COPY index.ts .
+COPY cache-keys.ts .
 RUN yarn build
 
 FROM prod-dependencies as release
-ENV CACHE_KEYS all
 ENV CACHE_KEYS_RETRIES 2
 COPY --from=build /usr/src/app/dist dist
 ENTRYPOINT ["node", "dist"]

cache-worker/cache-keys.ts

@@ -0,0 +1,5 @@
+export const cacheKeys: string[] = [
+  'de.serlo.org/example',
+  'de.serlo.org/anotherexample',
+  'spreadsheet-randomTokenOfTheSpreadSheetId-bla10921pçklj-sheet1!A:A-ROWS',
+]

cache-worker/index.ts

@@ -21,6 +21,7 @@
  */
 import { CacheWorker } from './src/cache-worker'
 import { Service } from './src/lib'
+import { cacheKeys } from './cache-keys'
 
 start()
 
@@ -31,7 +32,6 @@ async function start() {
     service: process.env.SERLO_SERVICE as Service,
   })
 
-  const cacheKeys = process.env.CACHE_KEYS as string
   const MAX_RETRIES = parseInt(process.env.CACHE_KEYS_RETRIES!)
 
   console.log('Updating cache values of the following keys:', cacheKeys)
@@ -48,7 +48,7 @@ async function start() {
 
 type Config = {
   cacheWorker: CacheWorker
-  cacheKeys: string
+  cacheKeys: string[]
   MAX_RETRIES: number
 }
 
@@ -64,9 +64,9 @@ async function run(config: Config, retries: number = 2) {
 }
 
 function retry(config: Config, retries: number) {
-    config.cacheWorker.errLog = []
-    console.log('Retrying to update cache')
-    setTimeout(async () => await run(config, ++retries), 5000)
+  config.cacheWorker.errLog = []
+  console.log('Retrying to update cache')
+  setTimeout(async () => await run(config, ++retries), 5000)
 }
 
 function declareFailure(errors: Error[]) {
@@ -77,7 +77,7 @@ function declareFailure(errors: Error[]) {
 }
 
 function checkSuccess(errLog: Error[]) {
-  if(errLog == []) {
+  if (errLog == []) {
     console.log('Cache successfully updated')
     return true
   }