Content-Type header [application/x-www-form-urlencoded] is not supported

Question

I have integrated Elasticsearch (Version 5.5) into Gitlab and try to use it. This is the command I send from an external windows client:

curl -XGET gitlab.server:9200/ -H 'Content-Type: application/json' -d '{"query": {"simple_query_string" : {"fields" : ["content"], "query" : "foo bar -baz"}}}'

but it doesn't work. On the client I get these errors:

{"error":"Content-Type header [application/x-www-form-urlencoded] is not supported","status":406}
curl: (6) Could not resolve host: text
curl: (3) [globbing] unmatched brace in column 1
curl: (3) Bad URL, colon is first character
curl: (3) [globbing] unmatched brace in column 1
curl: (3) Bad URL, colon is first character
curl: (3) [globbing] bad range in column 2
curl: (6) Could not resolve host: query
curl: (3) Bad URL, colon is first character
curl: (3) [globbing] unmatched close brace/bracket in column 13

On the server in /var/log/elasticsearch/elasticsearch.log I can see no log messages.

However, running the same exact command as above from the linux server gives me a response without errors:

{
  "name" : "name",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "uuid",
  "version" : {
    "number" : "5.5.0",
    "build_hash" : "260387d",
    "build_date" : "2017-06-30T23:16:05.735Z",
    "build_snapshot" : false,
    "lucene_version" : "6.6.0"
  },
  "tagline" : "You Know, for Search"
}

I tried adding http.content_type.required: true to the elasticsearch.yml, but the problem was the same. So, what am I doing wrong here? Why do I get a "Content-Type header not supported" from the Windows client? How can I solve this?

After changing the ' to " like this:

curl -XGET gitlab.server:9200/ -H "Content-Type: application/json" -d "{"query": {"simple_query_string" : {"fields" : ["content"], "query" : "foo bar -baz"}}}"

I recieve this response:

{
  "name" : "name",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "uuid",
  "version" : {
    "number" : "5.5.0",
    "build_hash" : "260387d",
    "build_date" : "2017-06-30T23:16:05.735Z",
    "build_snapshot" : false,
    "lucene_version" : "6.6.0"
  },
  "tagline" : "You Know, for Search"
}
curl: (6) Could not resolve host: bar

Answer 1

After changing the enclosing quotes from ' to ", escape the quotation marks " used inside the parameters as below:

curl -XGET gitlab.server:9200/ -H "Content-Type: application/json" -d "{\"query\": {\"simple_query_string\" : {\"fields\" : [\"content\"], \"query\" : \"foo bar -baz\"}}}"

An alternative is to put the json into a file, and use the @ prefix for the parameters.

json.txt

{
  "query": {
    "simple_query_string" : { 
      "fields" : ["content"], 
      "query" : "foo bar -baz"
    }
  }
}

and run curl as below:

curl -XGET gitlab.server:9200/ -H "Content-Type: application/json" -d @json.txt