go-elasticsearch: Elastic 官方的 Go 语言客户端

go get -u github.com/elastic/go-elasticsearch

require github.com/elastic/go-elasticsearch v0.0.0

git clone https://github.com/elastic/go-elasticsearch.git && cd go-elasticsearch

mkdir my-elasticsearch-app && cd my-elasticsearch-app
cat > go.mod <<-END  module my-elasticsearch-app
  require github.com/elastic/go-elasticsearch v0.0.0END
cat > main.go <<-END  package main
  import (    "log"
    "github.com/elastic/go-elasticsearch"  )
  func main() {    es, _ := elasticsearch.NewDefaultClient()    log.Println(es.Info())  }END
go run main.go

es, err := elasticsearch.NewDefaultClient()if err != nil {  log.Fatalf("Error creating the client: %s", err)}
res, err := es.Info()if err != nil {  log.Fatalf("Error getting response: %s", err)}
log.Println(res)
// [200 OK] {//   "name" : "node-1",//   "cluster_name" : "go-elasticsearch"// ...

cfg := elasticsearch.Config{  Addresses: []string{    "http://localhost:9200",    "http://localhost:9201",  },  Transport: &http.Transport{    MaxIdleConnsPerHost:   10,    ResponseHeaderTimeout: time.Second,    DialContext:           (&net.Dialer{Timeout: time.Second}).DialContext,    TLSClientConfig: &tls.Config{      MaxVersion:         tls.VersionTLS11,      InsecureSkipVerify: true,    },  },}
es, err := elasticsearch.NewClient(cfg)// ...

// $ go run _examples/main.go
package main
import (  "context"  "encoding/json"  "log"  "strconv"  "strings"  "sync"
  "github.com/elastic/go-elasticsearch"  "github.com/elastic/go-elasticsearch/esapi")
func main() {  log.SetFlags(0)
  var (    r  map[string]interface{}    wg sync.WaitGroup  )
  // Initialize a client with the default settings.  //  // An `ELASTICSEARCH_URL` environment variable will be used when exported.  //  es, err := elasticsearch.NewDefaultClient()  if err != nil {    log.Fatalf("Error creating the client: %s", err)  }
  // 1. Get cluster info  //  res, err := es.Info()  if err != nil {    log.Fatalf("Error getting response: %s", err)  }  // Deserialize the response into a map.  if err := json.NewDecoder(res.Body).Decode(&r); err != nil {    log.Fatalf("Error parsing the response body: %s", err)  }  // Print version number.  log.Printf("~~~~~~~> Elasticsearch %s", r["version"].(map[string]interface{})["number"])
  // 2. Index documents concurrently  //  for i, title := range []string{"Test One", "Test Two"} {    wg.Add(1)
    go func(i int, title string) {      defer wg.Done()
      // Set up the request object directly.      req := esapi.IndexRequest{        Index:      "test",        DocumentID: strconv.Itoa(i + 1),        Body:       strings.NewReader(`{"title" : "` + title + `"}`),        Refresh:    "true",      }
      // Perform the request with the client.      res, err := req.Do(context.Background(), es)      if err != nil {        log.Fatalf("Error getting response: %s", err)      }      defer res.Body.Close()
      if res.IsError() {        log.Printf("[%s] Error indexing document ID=%d", res.Status(), i+1)      } else {        // Deserialize the response into a map.        var r map[string]interface{}        if err := json.NewDecoder(res.Body).Decode(&r); err != nil {          log.Printf("Error parsing the response body: %s", err)        } else {          // Print the response status and indexed document version.          log.Printf("[%s] %s; version=%d", res.Status(), r["result"], int(r["_version"].(float64)))        }      }    }(i, title)  }  wg.Wait()
  log.Println(strings.Repeat("-", 37))
  // 3. Search for the indexed documents  //  // Use the helper methods of the client.  res, err = es.Search(    es.Search.WithContext(context.Background()),    es.Search.WithIndex("test"),    es.Search.WithBody(strings.NewReader(`{"query" : { "match" : { "title" : "test" } }}`)),    es.Search.WithTrackTotalHits(true),    es.Search.WithPretty(),  )  if err != nil {    log.Fatalf("ERROR: %s", err)  }  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.Fatalf("[%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.Fatalf("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))}
// ~~~~~~~> Elasticsearch 7.0.0-SNAPSHOT// [200 OK] updated; version=1// [200 OK] updated; version=1// -------------------------------------// [200 OK] 2 hits; took: 7ms//  * ID=1, map[title:Test One]//  * ID=2, map[title:Test Two]// =====================================