[Examples] Fix cluster name conflict between Elasticsearch and OpenSearch

Author: llupa

examples/compose.yaml

@@ -127,6 +127,7 @@ services:
     elasticsearch:
         image: docker.elastic.co/elasticsearch/elasticsearch:9.2.2
         environment:
+            cluster.name: 'elasticsearch-cluster'
             discovery.type: 'single-node'
             xpack.security.enabled: false
             ES_JAVA_OPTS: '-Xms512m -Xmx512m'
@@ -149,6 +150,7 @@ services:
     opensearch:
         image: opensearchproject/opensearch
         environment:
+            cluster.name: 'opensearch-cluster'
             discovery.type: 'single-node'
             bootstrap.memory_lock: true
             indices.requests.cache.maximum_cacheable_size: 256
@@ -162,7 +164,7 @@ services:
                 soft: 65536
                 hard: 65536
         healthcheck:
-            test: [ 'CMD', 'curl', "-f", "http://127.0.0.1:9200" ]
+            test: [ 'CMD', 'curl', '-f', 'http://127.0.0.1:9200/_cluster/health' ]
             interval: 30s
             start_period: 120s
             timeout: 20s