✨ Finish curl download implementation

src/cdn/downloadWithCurl.ts

@@ -4,11 +4,13 @@ import * as childProcess from 'child_process';
  * Downloads a file using a curl child process, to allow for speed-limiting and timeout if download is too slow.
  * Takes as input the host domain name, the path and the file size
  */
-export default function downloadWithCurl({ host, path, tempFileName, size, resolve, reject }: {host: string, path: string, tempFileName: string, size: number, resolve: (downloadedFile: string) => void, reject: () => void}): void {
+export default function downloadWithCurl({ host, path, tempFileName }: {host: string, path: string, tempFileName: string}): Promise<string> {
+  return new Promise((resolve, reject) => {
     const url = `http://${host}${(path.substr(0, 1) === '/' ? '' : '/')}${path}`;
 
     const parameters: string[] = [
       //...
+      '--silent',
       '--limit-rate', '30m', //maximum speed of 30 MB/s = 240 MBit/s
       '--speed-limit', String(100 * 1024 * 1024), //abort if less than 100 MB in 15 seconds
       '--speed-time', '15',
@@ -18,5 +20,17 @@ export default function downloadWithCurl({ host, path, tempFileName, size, resol
 
     const spawnedProcess = childProcess.spawn('curl', parameters);
 
+    spawnedProcess.stderr.setEncoding('utf8');
+    spawnedProcess.stderr.on('data', (error) => {
+      reject(`Error in process:\n> curl ${parameters.join(' ')}\n${error}`);
+    });
+
+    spawnedProcess.on('exit', (code) => {
+      if (code === 0) {
         resolve(tempFileName);
+      } else {
+        reject(`Error in process:\n> curl ${parameters.join(' ')}\nNon-zero exit code ${code}.`);
+      }
+    });
+  });
 }

src/cdn/downloadWrapper.ts

@@ -23,10 +23,17 @@ export default async function downloadWrapper({ host, path, size, useCurl = fals
 
   //Download either via curl or natively with Node
   if (useCurl) {
-    const downloadResult = await new Promise((resolve, reject) => {
-      downloadWithCurl({ host, path, tempFileName, size, resolve, reject });
-    }) as string;
+    //Try up to three times
+    for (let i = 0; i < 3; i += 3) {
+      try {
+        const downloadResult = await downloadWithCurl({ host, path, tempFileName });
         return downloadResult;
+      } catch {
+        //ignore error and try again
+      }
+    }
+    //Download failed, throw error
+    throw new Error('Could not download with curl');
   } else {
     const downloadResult = await new Promise((resolve, reject) => {
       downloadUrlContents(host, path, tempFileName, resolve, reject);