elasticsearch: adjust for recent deprecations (#3710)

Signed-off-by: Adrian Cole <adrian@tetrate.io>

docker/test-images/zipkin-elasticsearch7/config/elasticsearch.yml

@@ -19,12 +19,12 @@ node.name: zipkin-elasticsearch
 # Enable development mode and disable bootstrap checks
 # See https://www.elastic.co/guide/en/elasticsearch/reference/current/bootstrap-checks.html
 discovery.type: single-node
+# Avoid deprecation errors: as of 8.x the only accepted value is true.
+cluster.routing.allocation.disk.watermark.enable_for_single_data_node: true
 
 # This is a test image, so we are not afraid to delete all indices. Avoids:
 #   Wildcard expressions or all indices are not allowed
 action.destructive_requires_name: false
-# Avoid "flood stage disk watermark" errors
-cluster.routing.allocation.disk.threshold_enabled: false
 # We don't use geoip
 ingest.geoip.downloader.enabled: false
 

zipkin-storage/elasticsearch/src/test/java/zipkin2/elasticsearch/integration/ITElasticsearchStorage.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2023 The OpenZipkin Authors
+ * Copyright 2015-2024 The OpenZipkin Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -163,12 +163,14 @@ static void aggregateDependencies(ElasticsearchStorage storage, List<Span> spans
     final AggregatedHttpResponse response =
       webClient.execute(HttpRequest.of(RequestHeaders.of(HttpMethod.GET,
         "/_migration/deprecations"))).aggregate().join();
-    if (!response.contentAscii().isEmpty()) {
+    String responseBody = response.contentAscii();
+    if (!responseBody.equals("""
+      {"cluster_settings":[],"node_settings":[],"index_settings":{},"ml_settings":[],"ccr_auto_followed_system_indices":[]}""")) {
       LOGGER.warn("The ElasticSearch instance used during IT's is using deprecated features or "
         + "configuration. This is likely nothing to be really worried about (for example 'xpack.monitoring.enabled' "
         + "setting), but nevertheless it should be looked at to see if our docker image used during "
         + "integration tests needs updating for the next version of ElasticSearch. "
-        + "See https://www.elastic.co/guide/en/elasticsearch/reference/current/migration-api-deprecation.html"
+        + "See https://www.elastic.co/guide/en/elasticsearch/reference/current/migration-api-deprecation.html "
         + "for more information. This is the deprecation warning we received:\n\n"
         + response.contentAscii());
     }