go-elasticsearch连接、查询、聚合elasticsearch

简介

go-elasticsearch是elasticsearch官方的Go版本客户端，兼容多个版本。

查看ES版本号

package main

import (
  "context"
  "log"
  "strings"

  elasticsearch "github.com/elastic/go-elasticsearch/v6"
  "github.com/elastic/go-elasticsearch/v6/esapi"
)

func main() {
  cfg := elasticsearch.Config{
    Addresses: []string{
      "http://user:pass@192.168.1.1:9200",
    },
  }
  es, _ := elasticsearch.NewClient(cfg)
  log.Println(elasticsearch.Version)
  res, _ := es.Info()
  defer res.Body.Close()
  log.Print(res)
}

查询单个文档

// 查询单个文档 GET /index/_doc/1
req := esapi.GetRequest{
  Index:        "index",
  DocumentType: "_doc",
  DocumentID:   "13",
}
res, err := req.Do(context.Background(), es)
if err != nil {
  log.Fatalf("Error:%s", err)
}
log.Print(res)

查询多个文档

// 查询多个文档
req1 := esapi.MgetRequest{
  Index:        "index",
  DocumentType: "_doc",
  Body:         strings.NewReader(`{"docs":[{"_id":"111"},{"_id":"222"}]}`),
}
res, err = req1.Do(context.Background(), es)
if err != nil {
  log.Fatalf("Error:%s", err)
}
log.Print(res)

搜索

// 搜索
req2 := esapi.SearchRequest{
  Index: []string{"index"},
  Body: strings.NewReader(`{"query":{"match":{"content":"老师"}}}`),
}
res, err := req2.Do(context.Background(), es)
if err != nil {
  log.Fatalf("Error:%s", err)
}
log.Print(res)

聚合

// 聚合
req2 := esapi.SearchRequest{
  Index: []string{"index"},
  Body: strings.NewReader(`{
    "aggs":
      {"2":
        {"date_histogram":{"field":"@timestamp","interval":"1d","time_zone":"Asia/Shanghai","min_doc_count":1}}
      }, 
    "query": {"bool":{"must":[
      {"match_all":{}}, 
      {"range": {"@timestamp":{"gte": 1666512528818,"lte": 1671696528818,"format": "epoch_millis"
    }}}
    ]}}
  }`),
}
res, err := req2.Do(context.Background(), es)
if err != nil {
  log.Fatalf("Error:%s", err)
}
log.Print(res)