api: add HTTP-like object uploader

[tatiana-nspcc]

Add POST /upload/{cid} API.

Close #111.

[tatiana-nspcc]

I receive an error while trying to use custom multipart reader:

2023-12-22T16:06:27.370Z        error   handlers/api.go:206     could not receive multipart/form        {"error": "multipart: NextPart: EOF"}

It's line

neofs-rest-gw/handlers/multipart/multipart.go

Line 343 in 312cb7d

return nil, fmt.Errorf("multipart: NextPart: %v", err)

[cthulhu-rider]

I receive an error while trying to use custom multipart reader:

@tatiana-nspcc

u dont need this manual multipart decoder

neofs-rest-gw/handlers/objects.go

Lines 819 to 830 in 312cb7d

	contentType := params.HTTPRequest.Header.Get("Content-Type")
	_, paramsCT, err := mime.ParseMediaType(contentType)
	if err != nil {
	resp := a.logAndGetErrorResponse("parse content type", err)
	return errorResponse.WithPayload(resp)
	}
	boundary := paramsCT["boundary"]
	if file, err = fetchMultipartFile(a.log, params.HTTPRequest.Body, boundary); err != nil {
	resp := a.logAndGetErrorResponse("could not receive multipart/form", err)
	return errorResponse.WithPayload(resp)
	}

try this:

	if swagFile, ok := params.File.(*swag.File); ok {
		header = swagFile.Header
		file = swagFile.Data
	} else {
		const fileKey = "file"
		file, header, err = params.HTTPRequest.FormFile(fileKey)
		if err != nil {
			resp := a.logAndGetErrorResponse(fmt.Sprintf("get file %q from HTTP request", fileKey), err)
			return errorResponse.WithPayload(resp)
		}
	}

[tatiana-nspcc]

Thanks, @cthulhu-rider I've used that.

When I tried to run the test cases, I noticed that http-gw doesn't care about the naming of the field for upload. In the examples (https://github.com/nspcc-dev/neofs-http-gw/blob/0b22557622db8551bfbfc8d0ff0fde51fbdea9c3/README.md#L538), I see the file field, but the test cases use the upload_file field name and sometimes file. However, any arbitrary name can be used for the field. For the rest-gw, we should choose a fixed name for the file field, I think. Which one should we choose?

[cthulhu-rider]

Which one should we choose?

definitely strict behavior. There may be several files in any request. API server must clearly distinguish them on the server and require strict compliance with the protocol for system stability.

However, any arbitrary name can be used for the field.

it's an incorrect behavior to me that will break if we add one more file into the request. Lucky we dont care bout HTTP GW anymore

For the rest-gw, we should choose a fixed name for the file field

payload (same as in the NeoFS native protocol). And we must double-check that server responds with 4XX (in practice 400 Bad Request, but most important that not 2XX) if we set any other name like file

[smallhive]

Looks like unused, it is better to remove

[tatiana-nspcc]

Yep, you're right, fixed. And also rebased to fresh master state.

[codecov]

Codecov Report

Attention: 163 lines in your changes are missing coverage. Please review.

Comparison is base (8a638bd) 13.70% compared to head (404baff) 14.27%.
Report is 1 commits behind head on master.

Files	Patch %	Lines
handlers/objects.go	0.00%	156 Missing ⚠️
handlers/util.go	90.90%	3 Missing and 1 partial ⚠️
handlers/api.go	0.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #124      +/-   ##
==========================================
+ Coverage   13.70%   14.27%   +0.57%     
==========================================
  Files          10       10              
  Lines        2080     2262     +182     
==========================================
+ Hits          285      323      +38     
- Misses       1765     1908     +143     
- Partials       30       31       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[cthulhu-rider]

is this redundant while having

neofs-rest-gw/spec/rest.yaml

Lines 994 to 1007 in eee7071

	Address:
	description: Address of the object in NeoFS.
	type: object
	properties:
	containerId:
	type: string
	objectId:
	type: string
	required:
	- containerId
	- objectId
	example:
	objectId: 8N3o7Dtr6T1xteCt6eRwhpmJ7JhME58Hyu1dvaswuTDd
	containerId: 5HZTn5qkRnmgSz9gSrw22CEdPPk6nQhkwf2Mgzyvkikv

?

[tatiana-nspcc]

No, while we are keeping the rest-gw in a working state and want to pass tests for http-gw. This is because the tests require object_id and container_id, but we've had containerId and objectId.