Handle properly if filename(file0) is missing

Also add example in documentation how to test upload with curl.

Signed-off-by: Denys Fedoryshchenko <denys.f@collabora.com>

Author: nuclearcat

README.md

@@ -86,6 +86,19 @@ curl -X GET https://localhost:3000/v1/checkauth \
 
 The server supports large file uploads up to 4GB and includes upload conflict protection to prevent concurrent uploads to the same file path. Downloads have a 30-second timeout for acquiring file locks.
 
+### Uploading Files with curl
+
+Use `curl`'s multipart form support to send the file contents (`file0`) and target path. The upload endpoint accepts both `/upload` and `/v1/file`.
+
+```bash
+curl -X POST http://localhost:3000/v1/file \
+    -H "Authorization: Bearer <JWT_TOKEN>" \
+    -F "path=artifacts/build-123" \
+    -F "file0=@/absolute/path/to/build-output.tar.xz"
+```
+
+The resulting object is stored under `artifacts/build-123/<local filename>`. Swap in `/upload` if you prefer the shorter alias or use the public host name instead of `localhost` when interacting with a remote server.
+
 ### Metrics
 
 The `/metrics` endpoint provides Prometheus-compatible metrics including:
@@ -96,4 +109,4 @@ Both metrics include hostname, diskname, and mount_point labels.
 
 ## API Documentation
 
-See [docs](docs/) for detailed API documentation.
+See [docs](docs/) for detailed API documentation.

src/main.rs

@@ -497,7 +497,11 @@ async fn ax_post_file(
                     file0 = data.to_vec();
                     match filename {
                         Some(filename) => file0_filename = filename.to_string(),
-                        None => todo!(),
+                        None => {
+                            let error_msg = "No filename provided".to_string();
+                            eprintln!("{}", error_msg);
+                            return (StatusCode::BAD_REQUEST, error_msg.into_bytes());
+                        }
                     }
                 } else {
                     debug_log!("Unknown field {}: {} bytes", name, data.len());