Fixes unexpected error when request using pulsar 2.4.2 proxy

[zymap]

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Motivation

When sending a GET or DELETE request to the Pulsar proxy, the server
always threw an IllegalArgumentException. By my test that's because
we are setting the Content-Type for a request without the request body.
We remove the Content-Type if the request is GET or DELETE.

Modifications

• Remove the header Content-Type for the GET and DELETE requests

[sijie]

@zymap does pulsarctl work for 2.4.1 or 2.4.0? What has been changed in pulsar 2.4.2 to fail pulsarctl?

[zymap]

@sijie
Yes. Pulsarctl works well on 2.4.1 and 2.4.0. I think the problem due to the apache/pulsar#5361. I am not sure whether the server will think there is a request body when we add the header Content-Type for GET or DELETE. If there have a request body, the code ReplayableProxyContentProvider will save the body. Using curl -H "Content-Type: application/json" http://localhost:8080/admin/v2/tenats will reproduce the problem.

[sijie]

@zymap : if apache/pulsar#5361 is the root cause, shouldn't we look into that issue? Why do you think removing Content-Type: application/json from GET and DELETE requests is the right fix?

[zymap]

@sijie Yes. we should. I look into the issue, the request.contentLength will be -1 if we using GET or DELETE and specified the header Content-Type

Also, I find the https://tools.ietf.org/html/rfc7231#section-3.1.1.5,
A sender that generates a message containing a payload body SHOULD generate a Content-Type header field in that message unless the intended media type of the enclosed representation is unknown to the sender. If a Content-Type header field is not present, the recipient MAY either assume a media type of "application/octet-stream" ([RFC2046], Section 4.5.1) or examine the data to determine its type.. These words just tell we should add Content-Type when we have a request body. I am not sure should we add the Content-Type even if we have not the request body.

[sijie]

the request.contentLength will be -1 if we using GET or DELETE and specified the header Content-Type

Why it is -1? Is -1 the right value?

These words just tell we should add Content-Type when we have a request body. I am not sure should we add the Content-Type even if we have not the request body.

if that's the case, your fix is incorrect, no? If as what you said, wee should add content type based on whether we have content or not. but you are fixing based on the request type. why do you think a delete request will not have content?

[zymap]

-1 is a default value in Jetty. In Pulsarctl the content length is 0.

if that's the case, your fix is incorrect, no? If as what you said, wee should add content type based on whether we have content or not. but you are fixing based on the request type. why do you think a delete request will not have content?

Ah. You are right, I should add content-type based on whether we have content or not.

[zymap]

@sijie PTAL. Thanks.