refactor and removing unused code

pkg/datasource.go

@@ -2,32 +2,19 @@ package main
 
 import (
 	"context"
-	"crypto/tls"
 	"encoding/json"
 	"errors"
 	"fmt"
-	"net"
-	"net/http"
-	"net/url"
 	"time"
 
 	"github.com/alexanderzobnin/grafana-zabbix/pkg/gtime"
 	"github.com/alexanderzobnin/grafana-zabbix/pkg/zabbixapi"
-	hclog "github.com/hashicorp/go-hclog"
-	plugin "github.com/hashicorp/go-plugin"
 
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	"github.com/grafana/grafana-plugin-sdk-go/backend/log"
 	"github.com/grafana/grafana-plugin-sdk-go/data"
 )
 
-// ZabbixPlugin implements the Grafana backend interface and forwards queries to the ZabbixDatasourceInstance
-type ZabbixPlugin struct {
-	plugin.NetRPCUnsupportedPlugin
-	logger          hclog.Logger
-	datasourceCache *Cache
-}
-
 type ZabbixDatasource struct {
 	datasourceCache *Cache
 	logger          log.Logger
@@ -36,25 +23,32 @@ type ZabbixDatasource struct {
 // ZabbixDatasourceInstance stores state about a specific datasource
 // and provides methods to make requests to the Zabbix API
 type ZabbixDatasourceInstance struct {
-	url        *url.URL
-	authToken  string
 	zabbixAPI  *zabbixapi.ZabbixAPI
 	dsInfo     *backend.DataSourceInstanceSettings
 	Settings   *ZabbixDatasourceSettings
 	queryCache *Cache
-	httpClient *http.Client
 	logger     log.Logger
 }
 
-// NewZabbixDatasource returns new datasource instance.
-func (ds *ZabbixDatasource) NewZabbixDatasource(dsInfo *backend.DataSourceInstanceSettings) (*ZabbixDatasourceInstance, error) {
-	dsInstance, err := newZabbixDatasource(dsInfo)
+// NewZabbixDatasourceInstance returns an initialized zabbix datasource instance
+func NewZabbixDatasourceInstance(dsInfo *backend.DataSourceInstanceSettings) (*ZabbixDatasourceInstance, error) {
+	zabbixAPI, err := zabbixapi.New(dsInfo.URL)
 	if err != nil {
 		return nil, err
 	}
 
-	dsInstance.logger = ds.logger
-	return dsInstance, nil
+	zabbixSettings, err := readZabbixSettings(dsInfo)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ZabbixDatasourceInstance{
+		dsInfo:     dsInfo,
+		zabbixAPI:  zabbixAPI,
+		Settings:   zabbixSettings,
+		queryCache: NewCache(zabbixSettings.CacheTTL, 10*time.Minute),
+		logger:     log.New(),
+	}, nil
 }
 
 // CheckHealth checks if the plugin is running properly
@@ -114,59 +108,36 @@ func (ds *ZabbixDatasource) QueryData(ctx context.Context, req *backend.QueryDat
 	return qdr, nil
 }
 
-// func (p *ZabbixPlugin) GetDatasourceById(datasourceId int64) (*ZabbixDatasourceInstance, error) {
-// }
+// GetDatasource Returns cached datasource or creates new one
+func (ds *ZabbixDatasource) GetDatasource(pluginContext backend.PluginContext) (*ZabbixDatasourceInstance, error) {
+	dsSettings := pluginContext.DataSourceInstanceSettings
+	dsKey := fmt.Sprintf("%d-%d", pluginContext.OrgID, dsSettings.ID)
+	// Get hash to check if settings changed
+	dsInfoHash := HashDatasourceInfo(dsSettings)
 
-// newZabbixDatasource returns an initialized ZabbixDatasource
-func newZabbixDatasource(dsInfo *backend.DataSourceInstanceSettings) (*ZabbixDatasourceInstance, error) {
-	zabbixURLStr := dsInfo.URL
-	zabbixURL, err := url.Parse(zabbixURLStr)
+	if cachedData, ok := ds.datasourceCache.Get(dsKey); ok {
+		if cachedDS, ok := cachedData.(*ZabbixDatasourceInstance); ok {
+			cachedDSHash := HashDatasourceInfo(cachedDS.dsInfo)
+			if cachedDSHash == dsInfoHash {
+				return cachedDS, nil
+			}
+			ds.logger.Debug("Data source settings changed", "org", pluginContext.OrgID, "id", dsSettings.ID, "name", dsSettings.Name)
+		}
+	}
+
+	ds.logger.Debug("Initializing data source", "org", pluginContext.OrgID, "id", dsSettings.ID, "name", dsSettings.Name)
+	dsInstance, err := NewZabbixDatasourceInstance(pluginContext.DataSourceInstanceSettings)
 	if err != nil {
+		ds.logger.Error("Error initializing datasource", "error", err)
 		return nil, err
 	}
 
-	zabbixAPI, err := zabbixapi.New(dsInfo.URL)
-	if err != nil {
-		return nil, err
-	}
-
-	zabbixSettings, err := readZabbixSettings(dsInfo)
-	if err != nil {
-		return nil, err
-	}
-
-	return &ZabbixDatasourceInstance{
-		zabbixAPI:  zabbixAPI,
-		url:        zabbixURL,
-		dsInfo:     dsInfo,
-		Settings:   zabbixSettings,
-		queryCache: NewCache(zabbixSettings.CacheTTL, 10*time.Minute),
-		httpClient: &http.Client{
-			Transport: &http.Transport{
-				TLSClientConfig: &tls.Config{
-					Renegotiation: tls.RenegotiateFreelyAsClient,
-				},
-				Proxy: http.ProxyFromEnvironment,
-				Dial: (&net.Dialer{
-					Timeout:   30 * time.Second,
-					KeepAlive: 30 * time.Second,
-				}).Dial,
-				TLSHandshakeTimeout:   10 * time.Second,
-				ExpectContinueTimeout: 1 * time.Second,
-				MaxIdleConns:          100,
-				IdleConnTimeout:       90 * time.Second,
-			},
-			Timeout: time.Duration(time.Second * 30),
-		},
-	}, nil
+	ds.datasourceCache.Set(dsKey, dsInstance)
+	return dsInstance, nil
 }
 
 func readZabbixSettings(dsInstanceSettings *backend.DataSourceInstanceSettings) (*ZabbixDatasourceSettings, error) {
-	zabbixSettingsDTO := &ZabbixDatasourceSettingsDTO{
-		TrendsFrom:  "7d",
-		TrendsRange: "4d",
-		CacheTTL:    "1h",
-	}
+	zabbixSettingsDTO := &ZabbixDatasourceSettingsDTO{}
 
 	err := json.Unmarshal(dsInstanceSettings.JSONData, &zabbixSettingsDTO)
 	if err != nil {
@@ -207,32 +178,3 @@ func readZabbixSettings(dsInstanceSettings *backend.DataSourceInstanceSettings)
 
 	return zabbixSettings, nil
 }
-
-// GetDatasource Returns cached datasource or creates new one
-func (ds *ZabbixDatasource) GetDatasource(pluginContext backend.PluginContext) (*ZabbixDatasourceInstance, error) {
-	dsSettings := pluginContext.DataSourceInstanceSettings
-	dsInfoHash := HashDatasourceInfo(dsSettings)
-
-	if cachedData, ok := ds.datasourceCache.Get(dsInfoHash); ok {
-		if cachedDS, ok := cachedData.(*ZabbixDatasourceInstance); ok {
-			return cachedDS, nil
-		}
-	}
-
-	ds.logger.Debug(fmt.Sprintf("Datasource cache miss (Org %d Id %d '%s' %s)", pluginContext.OrgID, dsSettings.ID, dsSettings.Name, dsInfoHash))
-
-	dsInstance, err := ds.NewZabbixDatasource(pluginContext.DataSourceInstanceSettings)
-	if err != nil {
-		ds.logger.Error("Error initializing datasource", "error", err)
-		return nil, err
-	}
-
-	ds.datasourceCache.Set(dsInfoHash, dsInstance)
-	return dsInstance, nil
-}
-
-func BuildAPIResponse(responseData *interface{}) (*ZabbixAPIResourceResponse, error) {
-	return &ZabbixAPIResourceResponse{
-		Result: *responseData,
-	}, nil
-}