关于golang 进行 elasticsearch 操作的简单封装

package esmodels
import "encoding/json"
// es 原始请求结果定义
// es 查询请求 map
type EsSearchMap map[string]interface{}
type EsSearchArray []EsSearchMap
// type EsSearchResponseMap map[string]interface{}
// es 查询的 hits 数组中的一个结构
type EsSearchHitsBase struct {
    Index string  `json:"_index"`
    Id    string  `json:"_id"`
    Score float64 `json:"_score"`
}
// es 查询的 hits 数组中的一个结构
type EsSearchHitsSource struct {
    EsSearchHitsBase
    Source    json.RawMessage `json:"_source"`
    Highlight json.RawMessage `json:"highlight"`
}
// es 查询的 hits 中的 total
type EsSearchHitsTotal struct {
    Value    int64  `json:"value"`
    Relation string `json:"relation"`
}
// es 查询的 hits
type EsSearchHits struct {
    Total    EsSearchHitsTotal     `json:"total"`
    Hits     []*EsSearchHitsSource `json:"hits"`
    MaxScore float64               `json:"max_score"`
}
type EsSearchSimple struct {
    Hits         EsSearchHits   `json:"hits"`
    Aggregations EsAggregations `json:"aggregations"`
}

4. 封装的 golang 代码示例,会用到 github.com/elastic/go-elasticsearch/v8 库

package function
import (
    "bytes"
    "context"
    "encoding/json"
    "fmt"
    "project/models/esmodels"
    "strings"
    "github.com/elastic/go-elasticsearch/v8"
    "github.com/elastic/go-elasticsearch/v8/esapi"
)
// 与业务逻辑无关的公共 es 方法
// 简单查询
func EsSimpleSearch(es *elasticsearch.Client,query esmodels.EsSearchMap, index []string, pretty bool) (queryRes *esmodels.EsSearchSimple, err error) {
    // 将查询 DSL 转换为 JSON
    if IsTestEnv() {
        var queryBytes []byte
        queryBytes, err = json.Marshal(query)
        if err != nil {
            return
        }
        queryString := string(queryBytes)
        logs.Debug("EsSimpleSearch -- qurey: %v", queryString)
    }
    var buf bytes.Buffer
    if err = json.NewEncoder(&buf).Encode(query); err != nil {
        err = fmt.Errorf("es transform query to json fail, err:%v", err)
        return
    }
    req := esapi.SearchRequest{
        Index:  index, // 索引名
        Body:   &buf,
        Pretty: pretty, // 格式化输出
    }
    res, err := req.Do(context.Background(), es)
    if err != nil {
        err = fmt.Errorf("es request search fail, err:%v", err)
        return
    }
    defer res.Body.Close()
    if res.IsError() {
        err = fmt.Errorf("es search response fail, err:%v", err)
        return
    }
    logs.Debug("EsSimpleSearch, query: %v, response:%v", query, res.Body)
    // Parse the response
    queryRes = &esmodels.EsSearchSimple{}
    // queryRes := EsSearchMap{}
    if err = json.NewDecoder(res.Body).Decode(&queryRes); err != nil {
        err = fmt.Errorf("es search decode fail, err:%v", err)
        return
    }
    if IsTestEnv() {
        var queryBytes []byte
        queryBytes, err = json.Marshal(queryRes)
        if err != nil {
            return
        }
        queryString := string(queryBytes)
        logs.Debug("EsSimpleSearch -- response: %v", queryString)
    }
    return
}

5.使用示例

query := esmodels.EsSearchMap{
    "query": esmodels.EsQuery{
        "match_all": nil,
    },
}
tlsClientConfig := &tls.Config{
        InsecureSkipVerify: true, // 忽略证书验证
    }
    cfg := elasticsearch.Config{
        Addresses: conf.EsAddresses,
        Username:  conf.EsUserName,
        Password:  conf.EsPassword,
        CACert:    cert,
        Transport: &http.Transport{
            MaxIdleConnsPerHost: conf.EsMaxIdleConns, // 设置每个主机的最大空闲连接数
            TLSClientConfig:     tlsClientConfig,
        },
    }
client, err := elasticsearch.NewClient(cfg)
index := []string{"your-index-name"}
queryRes, err := EsSimpleSearch(client, query, index, true)

for _, hit := range queryRes.Hits.Hits {
        yourObject := YourObject{}
        if err := json.Unmarshal(hit.Source, & yourObject); err != nil {
            continue
        }
        ....
}