Template upload shows generic "Request failed with status code 500" instead of actual error message #11513
Description
problem
ISSUE TYPE
- Bug Report
COMPONENT NAME
UI, Template Upload, Error Handling
SUMMARY
Template upload shows generic "Request failed with status code 500" error in UI instead of displaying the actual server error message, making debugging
impossible for users.
versions
CLOUDSTACK VERSION
4.20.1.0
CONFIGURATION
Advanced networking, KVM hypervisor
OS / ENVIRONMENT
Ubuntu 22.04, KVM hosts
The steps to reproduce the bug
STEPS TO REPRODUCE
1. Go to Templates → Register Template
2. Upload a QCOW2 file that has format detection issues (e.g., with DOS/MBR boot sector)
3. Select "QCOW2" as format
4. Click Register Template
5. Observe error message in UI
What to do about it?
EXPECTED RESULTS
UI should display the actual error message from server, such as:
"File type mismatch between uploaded file and selected format. Selected file format: QCOW2. Received: DOS/MBR boot sector, extended partition table (last)"
ACTUAL RESULTS
UI shows useless generic error:
"Upload Failed - Failed to upload Template - Error: Request failed with status code 500"
Meanwhile server logs show the actual useful error:
2025-08-25 20:53:50,648 WARN [c.c.a.AlertManagerImpl] Template Template {"format":"QCOW2","id":224,"name":"Ubuntu Server 24.04 Custom"} failed to upload.
Error details: File type mismatch between uploaded file and selected format. Selected file format: QCOW2. Received: DOS/MBR boot sector, extended partition
table (last)
Users are forced to check server logs to understand why uploads fail.