Content-Type with charset causes failed pipeline

[jrtitus]

Good request:

$ http :59770/api/v2/trigger Content-Type:application/json;charset=utf-8 action=set deviceName=SomeDevice commandName=SomeCommand resourceName=SomeResource value=42
HTTP/1.1 200 OK
Content-Length: 36
Content-Type: application/json
Date: Thu, 16 Sep 2021 22:06:19 GMT

{
    "apiVersion": "v2",
    "statusCode": 200
}

Bad request:

$ http :59770/api/v2/trigger Content-Type:"application/json;charset=utf-8" action=set deviceName=SomeDevice commandName=SomeCommand resourceName=SomeResource value=42
HTTP/1.1 400 Bad Request
Content-Length: 155
Content-Type: text/plain; charset=utf-8
Date: Thu, 16 Sep 2021 21:59:48 GMT

unable to process custom object received of type 'send-command/functions.ActionRequest': unsupported content-type 'application/json;charset=utf-8' recieved

Error message from the application service:

level=ERROR ts=2021-09-16T23:02:21.4004789Z app=app-send-command source=runtime.go:308 msg="unable to process custom object received of type 'send-command/functions.ActionRequest': unsupported content-type 'application/json;charset=utf-8' recieved. X-Correlation-ID="

The previous example was done using HTTPie, but I initially found this was an issue when attempting to make this same request from a .NET core application using

private static readonly HttpClient client = new HttpClient();
// ...
client.BaseAddress = new Uri($"http://{host}:{port}");
var content = new StringContent(
	JsonConvert.SerializeObject(request),
	Encoding.UTF8,
	"application/json"
);
client.PostAsync("api/v2/trigger", content);

I think the issue is coming from this switch statement, or the envelope.ContentType isn't being converted well.

app-functions-sdk-go/internal/runtime/runtime.go

Lines 323 to 332 in 0793683

	switch envelope.ContentType {
	case common.ContentTypeJSON:
	err = json.Unmarshal(envelope.Payload, target)
	case common.ContentTypeCBOR:
	err = cbor.Unmarshal(envelope.Payload, target)
	default:
	err = fmt.Errorf("unsupported content-type '%s' recieved", envelope.ContentType)
	}

[lenny-goodell]

It is the addition of the ;charset=utf-8 on the end that is causing the error. application/json;charset=utf-8 is not currently supported.

[jrtitus]

Wow, I thought I had tried that and came up with the same result, but I now see what is happening. When I make the request with HTTPie, it treats the ; character as a separator and sets "charset":"utf-8" in the POST body instead of as part of the header. With the quotes, it makes sure to keep it as part of the Content-Type header, so my initial thought was skewed by that.

I confirmed that with quotes, and without ;charset=utf-8 works, so it's not the quotes. I'll update the title of the issue to reflect that.

$ http :59770/api/v2/trigger Content-Type:"application/json" action=set deviceName=SomeDevice commandName=SomeCommand resourceName=SomeResource value=42

HTTP/1.1 200 OK
Content-Length: 36
Content-Type: application/json
Date: Fri, 17 Sep 2021 16:25:52 GMT

{
    "apiVersion": "v2",
    "statusCode": 200
}

[jrtitus]

@lenny-intel Do you think the solution to this might simply be to split envelope.ContentType on the ; character in order to make an accurate comparison? json.Unmarshal doesn't really care what the charset is, right?

[lenny-goodell]

Yes, split and ignore all but the first item.