Add documentation in the save and restore applications.properties whi…

…ch explains how to use an authenticated client to elastic.

Signed-off-by: Mariana González Velarde <mariana@fnal.gov>

services/save-and-restore/src/main/resources/application.properties

@@ -9,6 +9,17 @@ server.port=8080
 elasticsearch.network.host=localhost
 elasticsearch.http.port=9200
 
+# The value for the `Authorization` header used in requests to the Elasticsearch server.
+# This header supports token-based or API key-based authentication.
+# See https://www.elastic.co/guide/en/elasticsearch/client/java-api-client/8.12/_other_authentication_methods.html
+elasticsearch.authorization.header =
+
+# Username and password for basic authentication with the Elasticsearch server.
+# These credentials are only used if `elasticsearch.authorization.header` is not set.
+elasticsearch.authorization.username =
+elasticsearch.authorization.password =
+
+
 # Do not change this!
 spring.jackson.serialization.write-dates-as-timestamps=false