Adding sync external assets feature.

backend/src/sync-assets.ts

@@ -0,0 +1,32 @@
+import axios from 'axios';
+import * as fs from 'fs';
+const fsPromises = fs.promises;
+import config from './config';
+import logger from './logger';
+
+const PATH = './';
+
+class SyncAssets {
+  constructor() { }
+
+  public async syncAssets() {
+    for (const url of config.MEMPOOL.EXTERNAL_ASSETS) {
+      await this.downloadFile(url);
+    }
+  }
+
+  private async downloadFile(url: string) {
+    const fileName = url.split('/').slice(-1)[0];
+    logger.info(`Downloading external asset: ${fileName}...`);
+    try {
+      const response = await axios.get(url, {
+        responseType: 'stream', timeout: 30000
+      });
+      await fsPromises.writeFile(PATH + fileName, response.data);
+    } catch (e: any) {
+      throw new Error(`Failed to download external asset. ` + e);
+    }
+  }
+}
+
+export default new SyncAssets();