feat: use config file for maxRequestBodySize

closes !20

src/app.ts

@@ -14,6 +14,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 import {
+  SCConfigFile,
   SCNotFoundErrorResponse,
   SCRequestBodyTooLargeErrorResponse,
   SCSyntaxErrorResponse,
@@ -40,6 +41,7 @@ import {Elasticsearch} from './storage/elasticsearch/Elasticsearch';
 
 export const app = express();
 const isTestEnvironment = process.env.NODE_ENV !== 'production';
+const configFile: SCConfigFile = app.get('config');
 
 async function configureApp() {
   // request loggers have to be the first middleware to be set in express
@@ -73,7 +75,7 @@ async function configureApp() {
     const chunkGatherer = (chunk: Buffer) => {
       bodySize += chunk.byteLength;
       // when adding each chunk size to the total size, check how large it now is.
-      if (bodySize > 512 * 1024) {
+      if (bodySize > configFile.backend.maxRequestBodySize) {
         req.off('data', chunkGatherer);
         req.off('end', endCallback);
         // return an error in the response