Indices Exists API missing include_type_name in REST API spec

[russcam]

Issue

Relates: elastic/elasticsearch-net#3901

The REST API spec for indices.exists.json is missing include_type_name in 6.8.0:

elasticsearch/rest-api-spec/src/main/resources/rest-api-spec/api/indices.exists.json

Lines 16 to 42 in 1263279

	"local": {
	"type": "boolean",
	"description": "Return local information, do not retrieve the state from master node (default: false)"
	},
	"ignore_unavailable": {
	"type": "boolean",
	"description": "Ignore unavailable indexes (default: false)"
	},
	"allow_no_indices": {
	"type": "boolean",
	"description": "Ignore if a wildcard expression resolves to no concrete indices (default: false)"
	},
	"expand_wildcards": {
	"type": "enum",
	"options": [ "open", "closed", "none", "all" ],
	"default": "open",
	"description": "Whether wildcard expressions should get expanded to open or closed indices (default: open)"
	},
	"flat_settings": {
	"type": "boolean",
	"description": "Return settings in flat format (default: false)"
	},
	"include_defaults": {
	"type": "boolean",
	"description": "Whether to return all default setting for each of the indices.",
	"default": false
	}

Sending an index exists request without include_type_name results in a Deprecation Warning HTTP header being returned:

Request

HEAD http://127.0.0.1:9200/foo HTTP/1.1
Accept: application/json
Content-Type: application/json
Host: 127.0.0.1:9200
Connection: Keep-Alive

Response

HTTP/1.1 200 OK
Warning: 299 Elasticsearch-6.8.1-1fad4e1 "[types removal] The parameter include_type_name should be explicitly specified in get indices requests to prepare for 7.0. In 7.0 include_type_name will default to 'false', which means responses will omit the type name in mapping definitions."
content-type: application/json; charset=UTF-8
content-length: 225

Sending a request with include_type_name=true or include_type_name=false results in no Deprecation Warning.

Feature

The indices.exists.json REST API spec should include include_type_name in the list of params, so that clients that generate API methods from the spec pick this up.

[elasticmachine]

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