无法与elasticsearch 8.1（java）建立连接

Question

我在docker中运行了elasticsearch 8.1，其中包含以下docker compose文件：

version: '3.7'

services:
  elasticsearch:
    image: docker.elastic.co/elasticsearch/elasticsearch:8.1.0
    container_name: es-node
    environment:
     - xpack.security.enabled=false
     - discovery.type=single-node
    volumes:
      - ./elastic-data:/usr/share/elasticsearch/data
    ports:
      - 9200:9200
    cap_add:
     - IPC_LOCK
    ulimits:
      memlock:
        soft: -1
        hard: -1
      nofile:
        soft: 65536
        hard: 65536
  kibana:
    image: docker.elastic.co/kibana/kibana:8.1.0
    container_name: kibana
    environment:
      - ELASTICSEARCH_HOST=http://localhost:9200
    ports:
      - 5601:5601
    depends_on:
      - elasticsearch

我正在尝试使用org.elasticsearch.client.RestClient向es集群发出一个简单的GET请求。

请求：

        Request request = new Request("GET", "_cluster/health");

        try {
            return restClient.performRequest(request).toString();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

Rest客户端初始化：

        var hosts = buildClusterHosts(transportAddresses);
        restClient = RestClient.builder(hosts).build();

        var esTransport = new RestClientTransport(restClient, new JacksonJsonpMapper());
        elasticsearchClient = new ElasticsearchClient(esTransport);

主要方法：

        var es = ElasticEightClient.builder()
                .transportAddresses("localhost:9200")
                .isElasticSniffEnabled(true)
                .build();


        System.out.println("Started elasticsearch with health: " + es.getHealth());

buildClusterHosts（）方法正确地构建了一个HttpHost数组（在本例中只有一个），并将其提供给rest客户端生成器。

从理论上讲，这应该足够了，但我一直受到以下因素的影响：java。网ConnectException:连接到[/172.20.0.2:9200]超时，我不知道为什么？

Answer 1

您似乎混淆了Elasticsearch的传输端口和Rest Api端口。

您首先需要公开传输层的端口，默认为9300

services:
  elasticsearch:
    ports:
      - 9300:9300

然后更新main方法

var es = ElasticEightClient.builder()
         .transportAddresses("localhost:9200")
         .isElasticSniffEnabled(true)
         .build();


System.out.println("Started elasticsearch with health: " + es.getHealth());