Simulate an index template

POST /_index_template/_simulate/{name}
POST /_index_template/_simulate

Get the index configuration that would be applied by a particular index template.

Authentication

Authorization: <value>

Elasticsearch APIs use key-based authentication. You must create an API key and use the encoded value in the request header. For example:

		curl -X GET "${ES_URL}/_cat/indices?v=true" \
  -H "Authorization: ApiKey ${API_KEY}"

For more information about where to find API keys for the Elasticsearch endpoint (${ES_URL}) for a project, go to Get started with Elasticsearch Serverless.

Request body

allow_auto_create boolean: This setting overrides the value of the action.auto_create_index cluster setting. If set to true in a template, then indices can be automatically created using that template even if auto-creation of indices is disabled via actions.auto_create_index. If set to false, then indices or data streams matching the template must always be explicitly created, and may never be automatically created.
index_patterns string: Array of wildcard (*) expressions used to match the names of data streams and indices during creation.
composed_of string[]: An ordered list of component template names. Component templates are merged in the order specified, meaning that the last component template specified has the highest precedence.
template object: Template to be applied. It may optionally include an aliases, mappings, or settings configuration.
data_stream object: If this object is included, the template is used to create data streams and their backing indices. Supports an empty object. Data streams require a matching index template with a data_stream object.
priority number: Priority to determine index template precedence when a new data stream or index is created. The index template with the highest priority is chosen. If no priority is specified the template is treated as though it is of priority 0 (lowest priority). This number is not automatically generated by Elasticsearch.
version number: Version number used to manage index templates externally. This number is not automatically generated by Elasticsearch.
_meta object: Optional user metadata about the index template. May have any contents. This map is not automatically generated by Elasticsearch.
ignore_missing_component_templates string[]: The configuration option ignore_missing_component_templates can be used when an index template references a component template that might not exist
deprecated boolean: Marks this index template as deprecated. When creating or updating a non-deprecated index template that uses deprecated components, Elasticsearch will emit a deprecation warning.

Response

application/json

Examples

Request Console 1 / 8 languages

To see what settings will be applied by a template before you add it to the cluster, you can pass a template configuration in the request body. The specified template is used for the simulation if it has a higher priority than existing templates.

Console Kibana Dev Tools

POST /_index_template/_simulate
{
  "index_patterns": ["my-index-*"],
  "composed_of": ["ct2"],
  "priority": 10,
  "template": {
    "settings": {
      "index.number_of_replicas": 1
    }
  }
}

JavaScript Elasticsearch JavaScript Client

const response = await client.indices.simulateTemplate({
  index_patterns: ["my-index-*"],
  composed_of: ["ct2"],
  priority: 10,
  template: {
    settings: {
      "index.number_of_replicas": 1,
    },
  },
});

Python Elasticsearch Python Client

resp = client.indices.simulate_template(
    index_patterns=[
        "my-index-*"
    ],
    composed_of=[
        "ct2"
    ],
    priority=10,
    template={
        "settings": {
            "index.number_of_replicas": 1
        }
    },
)

curl Shell

curl -X POST "$ELASTICSEARCH_URL/_index_template/_simulate" \
  -H "Authorization: ApiKey $ELASTIC_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "index_patterns": [
      "my-index-*"
    ],
    "composed_of": [
      "ct2"
    ],
    "priority": 10,
    "template": {
      "settings": {
        "index.number_of_replicas": 1
      }
    }
  }'

Java Elasticsearch Java Client

client.indices().simulateTemplate(s -> s
    .composedOf("ct2")
    .indexPatterns("my-index-*")
    .priority(10L)
    .template(t -> t
        .settings(se -> se
            .otherSettings("index.number_of_replicas", JsonData.fromJson("1"))
        )
    )
);

C# Elasticsearch .NET Client

var response = await client.Indices
    .SimulateTemplateAsync(d1 => d1
        .ComposedOf(["ct2"])
        .IndexPatterns(new[] { "my-index-*" })
        .Priority(10L)
        .Template(d2 => d2
            .Settings(d3 => d3
                .OtherSettings(new Dictionary<string, object>()
                {
                    { "index.number_of_replicas", 1 }
                })
            )
        )
    );

PHP Elasticsearch PHP Client

$resp = $client->indices()->simulateTemplate([
    "body" => [
        "index_patterns" => array(
            "my-index-*",
        ),
        "composed_of" => array(
            "ct2",
        ),
        "priority" => 10,
        "template" => [
            "settings" => [
                "index.number_of_replicas" => 1,
            ],
        ],
    ],
]);

Ruby Elasticsearch Ruby Client

response = client.indices.simulate_template(
  body: {
    "index_patterns": [
      "my-index-*"
    ],
    "composed_of": [
      "ct2"
    ],
    "priority": 10,
    "template": {
      "settings": {
        "index.number_of_replicas": 1
      }
    }
  }
)

Response

A successful response from POST /_index_template/_simulate with a template configuration in the request body. The response shows any overlapping templates with a lower priority.

{
  "template" : {
    "settings" : {
      "index" : {
        "number_of_replicas" : "1",
        "routing" : {
          "allocation" : {
            "include" : {
              "_tier_preference" : "data_content"
            }
          }
        }
      }
    },
    "mappings" : {
      "properties" : {
        "@timestamp" : {
          "type" : "date"
        }
      }
    },
    "aliases" : { }
  },
  "overlapping" : [
    {
      "name" : "final-template",
      "index_patterns" : [
        "my-index-*"
      ]
    }
  ]
}

Simulate an index template

Required authorization

Authentication

Path parameters

Query parameters

Request body

Response

Required authorization

Authentication

Path parameters

Query parameters

Request body { }

Response

Request body