Many Elasticsearch options are exposed via the package configuration in config.json, but there may be times when you need to add something custom to the elasticsearch.yml file. For instance, if you have written a custom plugin that requires special configuration, you must specify this block of YAML for the Elastic service to use.

Add your custom YAML when installing or updating the Elastic service. In the DC/OS UI, click Configure. In the left navigation bar, click elasticsearch and find the field for specifying custom elasticsearch YAML. You must base64 encode your block of YAML and enter this string into the field.

You can do this base64 encoding as part of your automated workflow, or you can do it manually with an online converter.

Note: You must only specify configuration options that are not already exposed in config.json.