Fix ERR_EMPTY_RESPONSE on script save by configuring server timeouts and improving error handling

back/api/script.ts

@@ -206,6 +206,7 @@ export default (app: Router) => {
       }),
     }),
     async (req: Request, res: Response, next: NextFunction) => {
+      const logger: Logger = Container.get('logger');
       try {
         let { filename, content, path } = req.body as {
           filename: string;
@@ -223,6 +224,7 @@ export default (app: Router) => {
         await writeFileWithLock(filePath, content);
         return res.send({ code: 200 });
       } catch (e) {
+        logger.error('🔥 error saving script: %o', e);
         return next(e);
       }
     },

back/services/http.ts

@@ -16,6 +16,17 @@ export class HttpServerService {
           metricsService.record('http_service_start', 1, {
             port: port.toString(),
           });
+
+          // Set server timeouts to prevent premature connection drops
+          if (this.server) {
+            // Timeout for receiving the entire request (including body) - 5 minutes
+            this.server.requestTimeout = 300000;
+            // Timeout for headers - 2 minutes  
+            this.server.headersTimeout = 120000;
+            // Keep-alive timeout - 65 seconds (slightly more than typical load balancer timeout)
+            this.server.keepAliveTimeout = 65000;
+          }
+
           resolve(this.server);
         });
 

back/shared/utils.ts

@@ -1,8 +1,9 @@
 import { lock } from 'proper-lockfile';
 import os from 'os';
 import path from 'path';
-import { writeFile, open, chmod } from 'fs/promises';
+import { writeFile, open, chmod, FileHandle } from 'fs/promises';
 import { fileExist } from '../config/util';
+import Logger from '../loaders/logger';
 
 function getUniqueLockPath(filePath: string) {
   const sanitizedPath = filePath
@@ -19,24 +20,61 @@ export async function writeFileWithLock(
   if (typeof options === 'string') {
     options = { encoding: options };
   }
+
+  // Ensure file exists before locking
   if (!(await fileExist(filePath))) {
-    const fileHandle = await open(filePath, 'w');
-    fileHandle.close();
+    let fileHandle: FileHandle | undefined;
+    try {
+      fileHandle = await open(filePath, 'w');
+    } catch (error) {
+      const errorMessage = error instanceof Error ? error.message : String(error);
+      throw new Error(`Failed to create file ${filePath}: ${errorMessage}`);
+    } finally {
+      if (fileHandle !== undefined) {
+        try {
+          await fileHandle.close();
+        } catch (closeError) {
+          // Log close error but don't throw to avoid masking the original error
+          Logger.error(`Failed to close file handle for ${filePath}:`, closeError);
+        }
+      }
+    }
   }
+
   const lockfilePath = getUniqueLockPath(filePath);
+  let release: (() => Promise<void>) | undefined;
 
-  const release = await lock(filePath, {
-    retries: {
-      retries: 10,
-      factor: 2,
-      minTimeout: 100,
-      maxTimeout: 3000,
-    },
-    lockfilePath,
-  });
-  await writeFile(filePath, content, { encoding: 'utf8', ...options });
-  if (options?.mode) {
-    await chmod(filePath, options.mode);
+  try {
+    release = await lock(filePath, {
+      retries: {
+        retries: 10,
+        factor: 2,
+        minTimeout: 100,
+        maxTimeout: 3000,
+      },
+      lockfilePath,
+    });
+  } catch (error) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    throw new Error(`Failed to acquire lock for ${filePath}: ${errorMessage}`);
+  }
+
+  try {
+    await writeFile(filePath, content, { encoding: 'utf8', ...options });
+    if (options?.mode) {
+      await chmod(filePath, options.mode);
+    }
+  } catch (error) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    throw new Error(`Failed to write to file ${filePath}: ${errorMessage}`);
+  } finally {
+    if (release) {
+      try {
+        await release();
+      } catch (error) {
+        // Log but don't throw on release failure
+        Logger.error(`Failed to release lock for ${filePath}:`, error);
+      }
+    }
   }
-  await release();
 }