lazy initializing es client

Signed-off-by: huanggze <loganhuang@yunify.com>

pkg/simple/client/logging/elasticsearch/elasticsearch.go

@@ -12,6 +12,7 @@ import (
 	"kubesphere.io/kubesphere/pkg/simple/client/logging/elasticsearch/versions/v7"
 	"kubesphere.io/kubesphere/pkg/utils/stringutils"
 	"strings"
+	"sync"
 )
 
 const (
@@ -22,7 +23,12 @@ const (
 
 // Elasticsearch implement logging interface
 type Elasticsearch struct {
-	c client
+	host    string
+	version string
+	index   string
+
+	c   client
+	mux sync.Mutex
 }
 
 // versioned es client interface
@@ -34,76 +40,105 @@ type client interface {
 }
 
 func NewElasticsearch(options *Options) (*Elasticsearch, error) {
-	var version, index string
+	var err error
-	es := &Elasticsearch{}
+	es := &Elasticsearch{
-
+		host:    options.Host,
-	if options.Version == "" {
+		version: options.Version,
-		var err error
+		index:   options.IndexPrefix,
-		version, err = detectVersionMajor(options.Host)
-		if err != nil {
-			return nil, err
-		}
-	} else {
-		version = options.Version
 	}
 
-	if options.IndexPrefix != "" {
+	switch es.version {
-		index = options.IndexPrefix
-	} else {
-		index = "logstash"
-	}
-
-	switch version {
 	case ElasticV5:
-		es.c = v5.New(options.Host, index)
+		es.c, err = v5.New(es.host, es.index)
 	case ElasticV6:
-		es.c = v6.New(options.Host, index)
+		es.c, err = v6.New(es.host, es.index)
 	case ElasticV7:
-		es.c = v7.New(options.Host, index)
+		es.c, err = v7.New(es.host, es.index)
+	case "":
+		es.c = nil
 	default:
-		return nil, fmt.Errorf("unsupported elasticsearch version %s", version)
+		return nil, fmt.Errorf("unsupported elasticsearch version %s", es.version)
 	}
 
-	return es, nil
+	return es, err
 }
 
-func (es *Elasticsearch) ES() *client {
+func (es *Elasticsearch) loadClient() error {
-	return &es.c
+	// Check if Elasticsearch client has been initialized.
-}
+	if es.c != nil {
+		return nil
+	}
 
-func detectVersionMajor(host string) (string, error) {
+	// Create Elasticsearch client.
-	// Info APIs are backward compatible with versions of v5.x, v6.x and v7.x
+	es.mux.Lock()
-	es := v6.New(host, "")
+	defer es.mux.Unlock()
-	res, err := es.Client.Info(
+
-		es.Client.Info.WithContext(context.Background()),
+	if es.c != nil {
+		return nil
+	}
+
+	// Detect Elasticsearch server version using Info API.
+	// Info API is backward compatible across v5, v6 and v7.
+	esv6, err := v6.New(es.host, "")
+	if err != nil {
+		return err
+	}
+
+	res, err := esv6.Client.Info(
+		esv6.Client.Info.WithContext(context.Background()),
 	)
 	if err != nil {
-		return "", err
+		return err
 	}
 	defer res.Body.Close()
 
 	var b map[string]interface{}
 	if err = jsoniter.NewDecoder(res.Body).Decode(&b); err != nil {
-		return "", err
+		return err
 	}
 	if res.IsError() {
 		// Print the response status and error information.
 		e, _ := b["error"].(map[string]interface{})
-		return "", fmt.Errorf("[%s] type: %v, reason: %v", res.Status(), e["type"], e["reason"])
+		return fmt.Errorf("[%s] type: %v, reason: %v", res.Status(), e["type"], e["reason"])
 	}
 
 	// get the major version
 	version, _ := b["version"].(map[string]interface{})
 	number, _ := version["number"].(string)
 	if number == "" {
-		return "", fmt.Errorf("failed to detect elastic version number")
+		return fmt.Errorf("failed to detect elastic version number")
 	}
 
+	var c client
 	v := strings.Split(number, ".")[0]
-	return v, nil
+	switch v {
+	case ElasticV5:
+		c, err = v5.New(es.host, es.index)
+	case ElasticV6:
+		c, err = v6.New(es.host, es.index)
+	case ElasticV7:
+		c, err = v7.New(es.host, es.index)
+	default:
+		err = fmt.Errorf("unsupported elasticsearch version %s", version)
+	}
+
+	if err != nil {
+		return err
+	}
+
+	es.c = c
+	es.version = v
+	return nil
 }
 
-func (es Elasticsearch) GetCurrentStats(sf logging.SearchFilter) (logging.Statistics, error) {
+func (es *Elasticsearch) GetCurrentStats(sf logging.SearchFilter) (logging.Statistics, error) {
+	var err error
+
+	err = es.loadClient()
+	if err != nil {
+		return logging.Statistics{}, err
+	}
+
 	body, err := newBodyBuilder().
 		mainBool(sf).
 		cardinalityAggregation().
@@ -129,7 +164,14 @@ func (es Elasticsearch) GetCurrentStats(sf logging.SearchFilter) (logging.Statis
 		nil
 }
 
-func (es Elasticsearch) CountLogsByInterval(sf logging.SearchFilter, interval string) (logging.Histogram, error) {
+func (es *Elasticsearch) CountLogsByInterval(sf logging.SearchFilter, interval string) (logging.Histogram, error) {
+	var err error
+
+	err = es.loadClient()
+	if err != nil {
+		return logging.Histogram{}, err
+	}
+
 	body, err := newBodyBuilder().
 		mainBool(sf).
 		dateHistogramAggregation(interval).
@@ -159,7 +201,14 @@ func (es Elasticsearch) CountLogsByInterval(sf logging.SearchFilter, interval st
 	return h, nil
 }
 
-func (es Elasticsearch) SearchLogs(sf logging.SearchFilter, f, s int64, o string) (logging.Logs, error) {
+func (es *Elasticsearch) SearchLogs(sf logging.SearchFilter, f, s int64, o string) (logging.Logs, error) {
+	var err error
+
+	err = es.loadClient()
+	if err != nil {
+		return logging.Logs{}, err
+	}
+
 	body, err := newBodyBuilder().
 		mainBool(sf).
 		from(f).
@@ -194,10 +243,16 @@ func (es Elasticsearch) SearchLogs(sf logging.SearchFilter, f, s int64, o string
 	return l, nil
 }
 
-func (es Elasticsearch) ExportLogs(sf logging.SearchFilter, w io.Writer) error {
+func (es *Elasticsearch) ExportLogs(sf logging.SearchFilter, w io.Writer) error {
+	var err error
 	var id string
 	var data []string
 
+	err = es.loadClient()
+	if err != nil {
+		return err
+	}
+
 	// Initial Search
 	body, err := newBodyBuilder().
 		mainBool(sf).

pkg/simple/client/logging/elasticsearch/elasticsearch_test.go

@@ -14,7 +14,7 @@ import (
 	"testing"
 )
 
-func TestDetectVersionMajor(t *testing.T) {
+func TestInitClient(t *testing.T) {
 	var tests = []struct {
 		fakeResp string
 		expected string
@@ -34,12 +34,13 @@ func TestDetectVersionMajor(t *testing.T) {
 			es := mockElasticsearchService("/", test.fakeResp, http.StatusOK)
 			defer es.Close()
 
-			result, err := detectVersionMajor(es.URL)
+			client := &Elasticsearch{host: es.URL}
+			err := client.loadClient()
 			if err != nil {
 				t.Fatal(err)
 			}
 
-			if diff := cmp.Diff(result, test.expected); diff != "" {
+			if diff := cmp.Diff(client.version, test.expected); diff != "" {
 				t.Fatalf("%T differ (-got, +want): %s", test.expected, diff)
 			}
 		})
@@ -222,15 +223,18 @@ func mockElasticsearchService(pattern, fakeResp string, fakeCode int) *httptest.
 	return httptest.NewServer(mux)
 }
 
-func newElasticsearchClient(srv *httptest.Server, version string) Elasticsearch {
+func newElasticsearchClient(srv *httptest.Server, version string) *Elasticsearch {
-	var es Elasticsearch
+	var es *Elasticsearch
 	switch version {
 	case ElasticV5:
-		es = Elasticsearch{c: v5.New(srv.URL, "ks-logstash-log")}
+		client, _ := v5.New(srv.URL, "ks-logstash-log")
+		es = &Elasticsearch{c: client}
 	case ElasticV6:
-		es = Elasticsearch{c: v6.New(srv.URL, "ks-logstash-log")}
+		client, _ := v6.New(srv.URL, "ks-logstash-log")
+		es = &Elasticsearch{c: client}
 	case ElasticV7:
-		es = Elasticsearch{c: v7.New(srv.URL, "ks-logstash-log")}
+		client, _ := v7.New(srv.URL, "ks-logstash-log")
+		es = &Elasticsearch{c: client}
 	}
 	return es
 }

pkg/simple/client/logging/elasticsearch/versions/v5/v5.go

@@ -8,7 +8,6 @@ import (
 	"github.com/elastic/go-elasticsearch/v5"
 	"github.com/elastic/go-elasticsearch/v5/esapi"
 	"io/ioutil"
-	"k8s.io/klog"
 	"time"
 )
 
@@ -17,16 +16,12 @@ type Elastic struct {
 	index  string
 }
 
-func New(address string, index string) *Elastic {
+func New(address string, index string) (*Elastic, error) {
 	client, err := elasticsearch.NewClient(elasticsearch.Config{
 		Addresses: []string{address},
 	})
-	if err != nil {
-		klog.Error(err)
-		return nil
-	}
 
-	return &Elastic{client: client, index: index}
+	return &Elastic{client: client, index: index}, err
 }
 
 func (e *Elastic) Search(body []byte, scroll bool) ([]byte, error) {

pkg/simple/client/logging/elasticsearch/versions/v6/v6.go

@@ -8,7 +8,6 @@ import (
 	"github.com/elastic/go-elasticsearch/v6"
 	"github.com/elastic/go-elasticsearch/v6/esapi"
 	"io/ioutil"
-	"k8s.io/klog"
 	"time"
 )
 
@@ -17,16 +16,12 @@ type Elastic struct {
 	index  string
 }
 
-func New(address string, index string) *Elastic {
+func New(address string, index string) (*Elastic, error) {
 	client, err := elasticsearch.NewClient(elasticsearch.Config{
 		Addresses: []string{address},
 	})
-	if err != nil {
-		klog.Error(err)
-		return nil
-	}
 
-	return &Elastic{Client: client, index: index}
+	return &Elastic{Client: client, index: index}, err
 }
 
 func (e *Elastic) Search(body []byte, scroll bool) ([]byte, error) {

pkg/simple/client/logging/elasticsearch/versions/v7/v7.go

@@ -8,7 +8,6 @@ import (
 	"github.com/elastic/go-elasticsearch/v7"
 	"github.com/elastic/go-elasticsearch/v7/esapi"
 	"io/ioutil"
-	"k8s.io/klog"
 	"time"
 )
 
@@ -17,16 +16,12 @@ type Elastic struct {
 	index  string
 }
 
-func New(address string, index string) *Elastic {
+func New(address string, index string) (*Elastic, error) {
 	client, err := elasticsearch.NewClient(elasticsearch.Config{
 		Addresses: []string{address},
 	})
-	if err != nil {
-		klog.Error(err)
-		return nil
-	}
 
-	return &Elastic{client: client, index: index}
+	return &Elastic{client: client, index: index}, err
 }
 
 func (e *Elastic) Search(body []byte, scroll bool) ([]byte, error) {