curl, API request works in Insomnia, but not in generated code for curl

Question

I have request in Insomnia. When I send it via Insomnia, no problemo. But when I generate source code for curl, it shows me this.

curl --request POST \
  --url URL \
  --header 'Authorization: bearer XXX' \
  --header 'content-type: multipart/form-data; boundary=---011000010111000001101001' \
  --cookie JSESSIONID=XXX \
  --form datasetFile=@FOLDER/producthierarchyl1-1.zip

{"message":"Bad Request","logref":null,"path":null,"_embedded":{"errors":[{"message":"Required argument [Publisher datasetFile] not specified","logref":null,"path":"/datasetFile","_embedded":{},"_links":{}}]},"_links":{"self":{"href":"/data-api/public-api/v4/datasets/ingestion/","templated":false,"profile":null,"deprecation":null,"title":null,"hreflang":null,"type":null,"name":null}}}

Insomnia output is like this.

> POST PATH HTTP/2
> Host: URL
> user-agent: insomnia/2022.3.0
> cookie: JSESSIONID=XXX
> authorization: bearer XXX
> content-type: multipart/form-data; boundary=X-INSOMNIA-BOUNDARY
> accept: */*
> content-length: 407

* STATE: DO => DID handle 0x170404b14008; line 2077 (connection #27)
* multi changed, check CONNECT_PEND queue!
* STATE: DID => PERFORMING handle 0x170404b14008; line 2196 (connection #27)

| --X-INSOMNIA-BOUNDARY
| Content-Disposition: form-data; name="datasetFile"; filename="producthierarchyl1-1.zip"
| Content-Type: application/zip
| PK�QU�}�%+producthierarchyl1-1.csvUT  բ�b
| --X-INSOMNIA-BOUNDARY--

* We are completely uploaded and fine
* HTTP/2 found, allow multiplexing

Where is the catch?

Thanks.

Answer 1

Remove the --header 'content-type: multipart/form-data; boundary=---011000010111000001101001 --header 'content-type: multipart/form-data; boundary=---011000010111000001101001 option.

It really should not be used like this: curl manages that header and the boundary on its own so changing it should only be done in the rare event you truly want and need to fiddle around with it.

A more minor second thing: --request POST should be dropped from the command line, as it is superfluous and easily cause problems if you add --location later on.

Updated

This flaw is said to have been fixed in a later version of Insomnia

Answer 2

For any folks bumping into this issue again, this answer correctly explains the reason for the problem.

Fortunately this should only be reproducible in versions 2022.3.0 and older versions of Insomnia.

If you use the latest one, 2022.5.1 , the generated curl will no longer have this problem, example of a multipart request generated:

curl --request GET \
  --url http://mockbin.org/request/anything \
  --header 'Content-Type: multipart/form-data' \
  --form test=test \
  --form test=@/Users/yourUserName/Desktop/somefile.txt