title: golang查询elasticsearch初体验
date: 2021-01-26 17:23:42
tags: golang elastictich
categories: k8s
thumbnail: https://ss1.bdstatic.com/70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=463240096,4017976753&fm=26&gp=0.jpg

库选择

golang查询es目前有两个库，一个是第三方的github.com/olivere/elastic，一个是官方的github.com/elastic/go-elasticsearch,根据以往被坑的经验，果断选择使用官方库

查询语法

这个只能看文档了，推荐官方文档，还是比较好懂的https://www.elastic.co/guide/cn/elasticsearch/guide/current/query-dsl-intro.html
研究了半天最后写的表达式如下

{
  "query": {
    "match": {
      "log": {
        "query": "qweasd1 10.0.11.129 注册了系统",
        "operator": "and"
      }
    }
  }
}

放到kibana中测试一下，符合预期

WX20210126-181745

编写代码

func search(c *gin.Context) {
    var (
        r map[string]interface{}
    )
    type SearchInfo struct {
        Word string `json:"word"`
    }
    var info SearchInfo
    if err := c.ShouldBindJSON(&info); err != nil {
        c.JSON(http.StatusOK, gin.H{"code": 1001, "message": err.Error()})
        return
    }
    var buf bytes.Buffer
    query := map[string]interface{}{
        "query": map[string]interface{}{
            "match_phrase": map[string]interface{}{
                "log":      info.Word,
                "operator": "and",
            },
        },
    }
    if err := json.NewEncoder(&buf).Encode(query); err != nil {
        log.Printf("Error encoding query: %s", err)
    }
    res, err := es.Search(
        es.Search.WithContext(context.Background()),
        es.Search.WithIndex("logs"),
        es.Search.WithBody(&buf),
        es.Search.WithTrackTotalHits(true),
        es.Search.WithPretty(),
    )
    if err != nil {
        log.Printf("Error getting response: %s", err)
        c.JSON(http.StatusOK, gin.H{"code": 1003, "message": err.Error()})
        return
    }
    defer res.Body.Close()

    if res.IsError() {
        var e map[string]interface{}
        if err := json.NewDecoder(res.Body).Decode(&e); err != nil {
            log.Fatalf("Error parsing the response body: %s", err)
        } else {
            // Print the response status and error information.
            log.Printf("[%s] %s: %s",
                res.Status(),
                e["error"].(map[string]interface{})["type"],
                e["error"].(map[string]interface{})["reason"],
            )
        }
    }
    if err := json.NewDecoder(res.Body).Decode(&r); err != nil {
        log.Printf("Error parsing the response body: %s", err)
    }
    // Print the response status, number of results, and request duration.
    log.Printf(
        "[%s] %d hits; took: %dms",
        res.Status(),
        int(r["hits"].(map[string]interface{})["total"].(map[string]interface{})["value"].(float64)),
        int(r["took"].(float64)),
    )
    // Print the ID and document source for each hit.
    for _, hit := range r["hits"].(map[string]interface{})["hits"].([]interface{}) {
        log.Printf(" * ID=%s, %s", hit.(map[string]interface{})["_id"], hit.(map[string]interface{})["_source"])
    }

    log.Println(strings.Repeat("=", 37))
    c.JSON(http.StatusOK, gin.H{"code": 0, "message": "OK"})
}

坑来了

2021/01/26 18:03:45 [400 Bad Request] parsing_exception: [match_phrase] query doesn't support multiple fields, found [log] and [operator]

这个库这种语法貌似不支持，换

query := map[string]interface{}{
        "query": map[string]interface{}{
            "bool": map[string]interface{}{
                "must": []interface{}{
                    map[string]interface{}{
                        "match_phrase": map[string]string{
                            "log": info.IP,
                        },
                    },
                    map[string]interface{}{
                        "match_phrase": map[string]string{
                            "log": info.UserName,
                        },
                    },
                    map[string]interface{}{
                        "match_phrase": map[string]string{
                            "log": info.Content,
                        },
                    },
                },
            },
        },
    }

每当这个时候，就无比怀念PHP的好

结果

2021/01/26 18:52:48 [200 OK] 1 hits; took: 362ms
2021/01/26 18:52:48  * ID=swyLPHcBVf2j-S8W5N2N, map[@timestamp:2021-01-26T02:35:08.178869714+00:00 docker:map[container_id:58e018a3bb44d1788aa1f8c7ae29708e224555cce714b18d30bc7ac3d56fe32c] kubernetes:map[container_image:cp-user-server:1.0.3 container_image_id:docker://sha256:015cc14bdab277d818775fb9fa1094f2d4056c65a91e355a8519713c7b2d9234 container_name:user host:hp labels:map[app:user pod-template-hash:868b789497] master_url:https://10.96.0.1:443/api namespace_id:598874aa-157d-46ad-a04a-2a069765a395 namespace_name:default pod_id:9b0242e2-e4fb-419a-a6aa-be6c0c6b3970 pod_name:user-868b789497-gsbsn] log:2021-01-26 10:35:08.178183 qweasd1 10.0.11.129 注册了系统
 stream:stdout tag:kubernetes.var.log.containers.user-868b789497-gsbsn_default_user-58e018a3bb44d1788aa1f8c7ae29708e224555cce714b18d30bc7ac3d56fe32c.log]
2021/01/26 18:52:48 =====================================

看结果成功取得了想要的数据，符合预期

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