You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: elasticsearch.go
    path of file: ./repos/malice/vendor/github.com/malice-plugins/pkgs/database/elasticsearch
    
    the code of the file until where you have to start completion: package elasticsearch

import (
	"context"
	"fmt"
	"os"
	"strings"
	"time"

	log "github.com/Sirupsen/logrus"
	"github.com/malice-plugins/pkgs/database"
	"github.com/malice-plugins/pkgs/utils"
	"github.com/olivere/elastic"
	"github.com/pkg/errors"
)

// Database is the elasticsearch malice database object
type Database struct {
	Host     string                 `json:"host,omitempty"`
	Port     string                 `json:"port,omitempty"`
	URL      string                 `json:"url,omitempty"`
	Username string                 `json:"username,omitempty"`
	Password string                 `json:"password,omitempty"`
	Index    string                 `json:"index,omitempty"`
	Type     string                 `json:"type,omitempty"`
	Plugins  map[string]interface{} `json:"plugins,omitempty"`
}

var (
	defaultIndex string
	defaultType  string
	defaultHost  string
	defaultPort  string
	defaultURL   string
)

func init() {
	defaultInd
    
func (db *Database) Init() error {

	// Create URL from host/port
	db.getURL()

	// Test connection to ElasticSearch
	err := db.TestConnection()
	if err != nil {
		return errors.Wrap(err, "failed to connect to database")
	}

	client, err := elastic.NewSimpleClient(
		elastic.SetURL(db.URL),
		elastic.SetBasicAuth(
			utils.Getopts(db.Username, "MALICE_ELASTICSEARCH_USERNAME", ""),
			utils.Getopts(db.Password, "MALICE_ELASTICSEARCH_PASSWORD", ""),
		),
	)
	if err != nil {
		return errors.Wrap(err, "failed to create elasticsearch simple client")
	}

	exists, err := client.IndexExists(db.Index).Do(context.Background())
	if err != nil {
		return errors.Wrap(err, "failed to check if index exists")
	}

	if !exists {
		// Index does not exist yet.
		createIndex, err := client.CreateIndex(db.Index).BodyString(mapping).Do(context.Background())
		if err != nil {
			return errors.Wrapf(err, "failed to create index: %s", db.Index)
		}

		if !createIndex.Acknowledged {
			log.Error("index creation not acknowledged")
		} else {
			log.Debugf("created index %s", db.Index)
		}
	} else {
		log.Debugf("index %s already exists", db.Index)
	}

	return nil
}