POST index/_settings with body produces wrong exception

[honzakral]

Elasticsearch version: 2.1 - master

Description of the problem including expected versus actual behavior: Sending even an empty body (url localhost:9200/test/_settings -d '' or curl localhost:9200/test/_settings -d '{}') results in a (wrong) exception - mapper_parsing_exception

Steps to reproduce:

1. curl -X PUT localhost:9200/test
2. curl localhost:9200/test/_settings -d ''

[nikoncode]

What behaviors are expected?

[honzakral]

Either for it to ignore the body and respond with the settings or provide a relevant exception saying that sending body is not allowed with this API

[clintongormley]

It's a POST request, not a GET request, and it is somehow matching a POST /{index}/_mapping handler

[alexshadow007]

@clintongormley
It is matching POST /{index}/{type} handler.
It is trying to create dynamic mapping for type _settings, but can't and throws MapperParsingException.

[jeff303]

I'm new to the project, so take everything here with a huge grain of salt. It's not clear to me how responding to the POST the same way as to the GET, or changing the exception could be accomplished cleanly.

GET /{index}/_settings is mapped in RestGetIndicesAction, with the _settings portion being covered by a feature. In theory, a specific POST handler could be added for /{index}/_settings but it probably shouldn't go in this class, since it's explicitly for GET requests.

Absent a special handler for this, even changing the exception would require some kind of special handling in RestIndexAction. But it would seem that prevents someone from dynamically indexing a document with type _settings, and why shouldn't that be allowed?

[SushantVarshney]

Also facing the same issue.Is there any way to overcome this?

[qwerty4030]

@clintongormley @jbertouch I think this may be user error. curl and sense automatically convert a GET request with a body to a POST. I was able to reproduce the error on latest master, but changing the request to the following gives the correct index settings (request body ignored):
curl -X GET localhost:9200/test/_settings -d ''

[jasontedor]

I think this may be user error.

@qwerty4030 Whether or not it's user error, there is the issue that a POST request to /{index}/_settings is being treated as an index request when ideally it would match the update settings handler for /{index}/_settings and return a 405 since this endpoint only accepts PUT requests. Instead, it's matching the POST handler for /{index}/{type} and that's why the we see a mapper parsing exception here.