elasticstream/source/elastic/search.go

package elastic

import (
	"context"
	"encoding/json"
	"fmt"
	"strings"
	"time"

	"github.com/elastic/go-elasticsearch/esapi"
	"github.com/elastic/go-elasticsearch/v8"
)

type SearchResponse struct {
	Hits struct {
		Total struct {
			Value int `json:"value"`
		} `json:"total"`
		Hits []struct {
			Index  string                 `json:"_index"`
			ID     string                 `json:"_id"`
			Source map[string]interface{} `json:"_source"`
		} `json:"hits"`
	} `json:"hits"`
}

// search is calling Elastic Search search API
func search(client *elasticsearch.Client, index string, offset, size *int) (*SearchResponse, error) {
	query := fmt.Sprintf(`{
		"query": {
			"match_all": {}
		}
	}`)

	// Create the search request
	req := esapi.SearchRequest{
		Index: []string{index},
		Body:  strings.NewReader(query),
		From:  offset,
		Size:  size,
	}

	// Perform the request
	ctx, _ := context.WithTimeout(context.TODO(), 5*time.Second)
	res, err := req.Do(ctx, client)
	if err != nil {
		return nil, fmt.Errorf("error getting response: %s", err)
	}
	defer res.Body.Close()

	if res.IsError() {
		return nil, fmt.Errorf("res.IsError() error: %s", res.String())
	}

	result := &SearchResponse{}
	if err := json.NewDecoder(res.Body).Decode(result); err != nil {
		return nil, fmt.Errorf("error parsing the response body: %s", err)
	}

	return result, nil
}