Fix goconst issues

See,
$ gometalinter --vendor --disable-all --enable=goconst --disable=gotype --deadline=6m ./...
build.go:113:15:warning: 2 other occurrence(s) of "linux" found in: build.go:119:15 build.go:491:34 (goconst)
build.go:119:15:warning: 2 other occurrence(s) of "linux" found in: build.go:113:15 build.go:491:34 (goconst)
build.go:491:34:warning: 2 other occurrence(s) of "linux" found in: build.go:113:15 build.go:119:15 (goconst)
build.go:381:21:warning: 2 other occurrence(s) of "windows" found in: build.go:423:13 build.go:487:13 (goconst)
build.go:423:13:warning: 2 other occurrence(s) of "windows" found in: build.go:381:21 build.go:487:13 (goconst)
build.go:487:13:warning: 2 other occurrence(s) of "windows" found in: build.go:381:21 build.go:423:13 (goconst)
pkg/api/dashboard.go:67:22:warning: 5 other occurrence(s) of "Anonymous" found in: pkg/api/dashboard.go:67:35 pkg/api/dashboard.go:131:10 pkg/api/dashboard.go:406:13 pkg/api/folder.go:98:22 pkg/api/folder.go:98:35 (goconst)
pkg/api/dashboard.go:67:35:warning: 5 other occurrence(s) of "Anonymous" found in: pkg/api/dashboard.go:67:22 pkg/api/dashboard.go:131:10 pkg/api/dashboard.go:406:13 pkg/api/folder.go:98:22 pkg/api/folder.go:98:35 (goconst)
pkg/api/dashboard.go:131:10:warning: 5 other occurrence(s) of "Anonymous" found in: pkg/api/dashboard.go:67:22 pkg/api/dashboard.go:67:35 pkg/api/dashboard.go:406:13 pkg/api/folder.go:98:22 pkg/api/folder.go:98:35 (goconst)
pkg/api/dashboard.go:406:13:warning: 5 other occurrence(s) of "Anonymous" found in: pkg/api/dashboard.go:67:22 pkg/api/dashboard.go:67:35 pkg/api/dashboard.go:131:10 pkg/api/folder.go:98:22 pkg/api/folder.go:98:35 (goconst)
pkg/api/folder.go:98:22:warning: 5 other occurrence(s) of "Anonymous" found in: pkg/api/dashboard.go:67:22 pkg/api/dashboard.go:67:35 pkg/api/dashboard.go:131:10 pkg/api/dashboard.go:406:13 pkg/api/folder.go:98:35 (goconst)
pkg/api/folder.go:98:35:warning: 5 other occurrence(s) of "Anonymous" found in: pkg/api/dashboard.go:67:22 pkg/api/dashboard.go:67:35 pkg/api/dashboard.go:131:10 pkg/api/dashboard.go:406:13 pkg/api/folder.go:98:22 (goconst)
pkg/api/index.go:63:47:warning: 2 other occurrence(s) of "light" found
in: pkg/api/index.go:91:22 pkg/api/index.go:93:16 (goconst)
pkg/api/index.go:91:22:warning: 2 other occurrence(s) of "light" found in: pkg/api/index.go:63:47 pkg/api/index.go:93:16 (goconst)
pkg/api/index.go:93:16:warning: 2 other occurrence(s) of "light" found in: pkg/api/index.go:63:47 pkg/api/index.go:91:22 (goconst)
pkg/components/null/float.go:71:25:warning: 2 other occurrence(s) of "null" found in: pkg/components/null/float.go:103:10 pkg/components/null/float.go:112:10 (goconst)
pkg/components/null/float.go:103:10:warning: 2 other occurrence(s) of "null" found in: pkg/components/null/float.go:71:25 pkg/components/null/float.go:112:10 (goconst)
pkg/components/null/float.go:112:10:warning: 2 other occurrence(s) of "null" found in: pkg/components/null/float.go:71:25 pkg/components/null/float.go:103:10 (goconst)
pkg/services/alerting/notifiers/pagerduty.go:79:16:warning: 2 other occurrence(s) of "Triggered metrics:\n\n" found in: pkg/services/alerting/notifiers/kafka.go:64:16 pkg/services/alerting/notifiers/opsgenie.go:98:16 (goconst)
pkg/services/alerting/notifiers/kafka.go:64:16:warning: 2 other occurrence(s) of "Triggered metrics:\n\n" found in: pkg/services/alerting/notifiers/pagerduty.go:79:16 pkg/services/alerting/notifiers/opsgenie.go:98:16 (goconst)
pkg/services/alerting/notifiers/opsgenie.go:98:16:warning: 2 other occurrence(s) of "Triggered metrics:\n\n" found in: pkg/services/alerting/notifiers/pagerduty.go:79:16 pkg/services/alerting/notifiers/kafka.go:64:16 (goconst)
pkg/social/social.go:85:11:warning: 2 other occurrence(s) of "grafana_com" found in: pkg/social/social.go:162:14 pkg/social/social.go:197:11 (goconst)
pkg/social/social.go:162:14:warning: 2 other occurrence(s) of "grafana_com" found in: pkg/social/social.go:85:11 pkg/social/social.go:197:11 (goconst)
pkg/social/social.go:197:11:warning: 2 other occurrence(s) of "grafana_com" found in: pkg/social/social.go:85:11 pkg/social/social.go:162:14 (goconst)
pkg/tsdb/elasticsearch/time_series_query.go:92:17:warning: 3 other occurrence(s) of "count" found in: pkg/tsdb/elasticsearch/response_parser.go:152:8 pkg/tsdb/elasticsearch/response_parser.go:167:31 pkg/tsdb/elasticsearch/response_parser.go:315:9 (goconst)
pkg/tsdb/elasticsearch/response_parser.go:152:8:warning: 3 other occurrence(s) of "count" found in: pkg/tsdb/elasticsearch/time_series_query.go:92:17 pkg/tsdb/elasticsearch/response_parser.go:167:31 pkg/tsdb/elasticsearch/response_parser.go:315:9 (goconst)
pkg/tsdb/elasticsearch/response_parser.go:167:31:warning: 3 other occurrence(s) of "count" found in: pkg/tsdb/elasticsearch/time_series_query.go:92:17 pkg/tsdb/elasticsearch/response_parser.go:152:8 pkg/tsdb/elasticsearch/response_parser.go:315:9 (goconst)
pkg/tsdb/elasticsearch/response_parser.go:315:9:warning: 3 other occurrence(s) of "count" found in: pkg/tsdb/elasticsearch/time_series_query.go:92:17 pkg/tsdb/elasticsearch/response_parser.go:152:8 pkg/tsdb/elasticsearch/response_parser.go:167:31 (goconst)
pkg/tsdb/elasticsearch/time_series_query.go:78:9:warning: 2 other occurrence(s) of "date_histogram" found in: pkg/tsdb/elasticsearch/response_parser.go:84:22 pkg/tsdb/elasticsearch/response_parser.go:369:24 (goconst)
pkg/tsdb/elasticsearch/response_parser.go:84:22:warning: 2 other occurrence(s) of "date_histogram" found in: pkg/tsdb/elasticsearch/time_series_query.go:78:9 pkg/tsdb/elasticsearch/response_parser.go:369:24 (goconst)
pkg/tsdb/elasticsearch/response_parser.go:369:24:warning: 2 other occurrence(s) of "date_histogram" found in: pkg/tsdb/elasticsearch/time_series_query.go:78:9 pkg/tsdb/elasticsearch/response_parser.go:84:22 (goconst)

build.go

@@ -22,6 +22,11 @@ import (
 	"time"
 )
 
+const (
+	windows = "windows"
+	linux   = "linux"
+)
+
 var (
 	//versionRe = regexp.MustCompile(`-[0-9]{1,3}-g[0-9a-f]{5,10}`)
 	goarch  string
@@ -110,13 +115,13 @@ func main() {
 		case "package":
 			grunt(gruntBuildArg("build")...)
 			grunt(gruntBuildArg("package")...)
-			if goos == "linux" {
+			if goos == linux {
 				createLinuxPackages()
 			}
 
 		case "package-only":
 			grunt(gruntBuildArg("package")...)
-			if goos == "linux" {
+			if goos == linux {
 				createLinuxPackages()
 			}
 
@@ -378,7 +383,7 @@ func ensureGoPath() {
 }
 
 func grunt(params ...string) {
-	if runtime.GOOS == "windows" {
+	if runtime.GOOS == windows {
 		runPrint(`.\node_modules\.bin\grunt`, params...)
 	} else {
 		runPrint("./node_modules/.bin/grunt", params...)
@@ -420,7 +425,7 @@ func build(binaryName, pkg string, tags []string) {
 		binary = fmt.Sprintf("./bin/%s", binaryName)
 	}
 
-	if goos == "windows" {
+	if goos == windows {
 		binary += ".exe"
 	}
 
@@ -484,11 +489,11 @@ func clean() {
 
 func setBuildEnv() {
 	os.Setenv("GOOS", goos)
-	if goos == "windows" {
+	if goos == windows {
 		// require windows >=7
 		os.Setenv("CGO_CFLAGS", "-D_WIN32_WINNT=0x0601")
 	}
-	if goarch != "amd64" || goos != "linux" {
+	if goarch != "amd64" || goos != linux {
 		// needed for all other archs
 		cgo = true
 	}

pkg/api/dashboard.go

@@ -22,6 +22,10 @@ import (
 	"github.com/grafana/grafana/pkg/util"
 )
 
+const (
+	anonString = "Anonymous"
+)
+
 func isDashboardStarredByUser(c *m.ReqContext, dashID int64) (bool, error) {
 	if !c.IsSignedIn {
 		return false, nil
@@ -64,7 +68,7 @@ func GetDashboard(c *m.ReqContext) Response {
 	}
 
 	// Finding creator and last updater of the dashboard
-	updater, creator := "Anonymous", "Anonymous"
+	updater, creator := anonString, anonString
 	if dash.UpdatedBy > 0 {
 		updater = getUserLogin(dash.UpdatedBy)
 	}
@@ -128,7 +132,7 @@ func getUserLogin(userID int64) string {
 	query := m.GetUserByIdQuery{Id: userID}
 	err := bus.Dispatch(&query)
 	if err != nil {
-		return "Anonymous"
+		return anonString
 	}
 	return query.Result.Login
 }
@@ -403,7 +407,7 @@ func GetDashboardVersion(c *m.ReqContext) Response {
 		return Error(500, fmt.Sprintf("Dashboard version %d not found for dashboardId %d", query.Version, dashID), err)
 	}
 
-	creator := "Anonymous"
+	creator := anonString
 	if query.Result.CreatedBy > 0 {
 		creator = getUserLogin(query.Result.CreatedBy)
 	}

pkg/api/folder.go

@@ -95,7 +95,7 @@ func toFolderDto(g guardian.DashboardGuardian, folder *m.Folder) dtos.Folder {
 	canAdmin, _ := g.CanAdmin()
 
 	// Finding creator and last updater of the folder
-	updater, creator := "Anonymous", "Anonymous"
+	updater, creator := anonString, anonString
 	if folder.CreatedBy > 0 {
 		creator = getUserLogin(folder.CreatedBy)
 	}

pkg/api/index.go

@@ -11,6 +11,12 @@ import (
 	"github.com/grafana/grafana/pkg/setting"
 )
 
+const (
+	// Themes
+	lightName = "light"
+	darkName  = "dark"
+)
+
 func setIndexViewData(c *m.ReqContext) (*dtos.IndexViewData, error) {
 	settings, err := getFrontendSettingsMap(c)
 	if err != nil {
@@ -60,7 +66,7 @@ func setIndexViewData(c *m.ReqContext) (*dtos.IndexViewData, error) {
 			OrgRole:                    c.OrgRole,
 			GravatarUrl:                dtos.GetGravatarUrl(c.Email),
 			IsGrafanaAdmin:             c.IsGrafanaAdmin,
-			LightTheme:                 prefs.Theme == "light",
+			LightTheme:                 prefs.Theme == lightName,
 			Timezone:                   prefs.Timezone,
 			Locale:                     locale,
 			HelpFlags1:                 c.HelpFlags1,
@@ -88,12 +94,12 @@ func setIndexViewData(c *m.ReqContext) (*dtos.IndexViewData, error) {
 	}
 
 	themeURLParam := c.Query("theme")
-	if themeURLParam == "light" {
+	if themeURLParam == lightName {
 		data.User.LightTheme = true
-		data.Theme = "light"
-	} else if themeURLParam == "dark" {
+		data.Theme = lightName
+	} else if themeURLParam == darkName {
 		data.User.LightTheme = false
-		data.Theme = "dark"
+		data.Theme = darkName
 	}
 
 	if hasEditPermissionInFoldersQuery.Result {

pkg/components/null/float.go

@@ -8,6 +8,10 @@ import (
 	"strconv"
 )
 
+const (
+	nullString = "null"
+)
+
 // Float is a nullable float64.
 // It does not consider zero values to be null.
 // It will decode to null, not zero, if null.
@@ -68,7 +72,7 @@ func (f *Float) UnmarshalJSON(data []byte) error {
 // It will return an error if the input is not an integer, blank, or "null".
 func (f *Float) UnmarshalText(text []byte) error {
 	str := string(text)
-	if str == "" || str == "null" {
+	if str == "" || str == nullString {
 		f.Valid = false
 		return nil
 	}
@@ -82,7 +86,7 @@ func (f *Float) UnmarshalText(text []byte) error {
 // It will encode null if this Float is null.
 func (f Float) MarshalJSON() ([]byte, error) {
 	if !f.Valid {
-		return []byte("null"), nil
+		return []byte(nullString), nil
 	}
 	return []byte(strconv.FormatFloat(f.Float64, 'f', -1, 64)), nil
 }
@@ -100,7 +104,7 @@ func (f Float) MarshalText() ([]byte, error) {
 // It will encode a blank string if this Float is null.
 func (f Float) String() string {
 	if !f.Valid {
-		return "null"
+		return nullString
 	}
 
 	return fmt.Sprintf("%1.3f", f.Float64)
@@ -109,7 +113,7 @@ func (f Float) String() string {
 // FullString returns float as string in full precision
 func (f Float) FullString() string {
 	if !f.Valid {
-		return "null"
+		return nullString
 	}
 
 	return fmt.Sprintf("%f", f.Float64)

pkg/services/alerting/notifiers/base.go

@@ -11,6 +11,10 @@ import (
 	"github.com/grafana/grafana/pkg/services/alerting"
 )
 
+const (
+	triggMetrString = "Triggered metrics:\n\n"
+)
+
 type NotifierBase struct {
 	Name         string
 	Type         string

pkg/services/alerting/notifiers/kafka.go

@@ -61,7 +61,7 @@ func (this *KafkaNotifier) Notify(evalContext *alerting.EvalContext) error {
 
 	state := evalContext.Rule.State
 
-	customData := "Triggered metrics:\n\n"
+	customData := triggMetrString
 	for _, evt := range evalContext.EvalMatches {
 		customData = customData + fmt.Sprintf("%s: %v\n", evt.Metric, evt.Value)
 	}

pkg/services/alerting/notifiers/opsgenie.go

@@ -95,7 +95,7 @@ func (this *OpsGenieNotifier) createAlert(evalContext *alerting.EvalContext) err
 		return err
 	}
 
-	customData := "Triggered metrics:\n\n"
+	customData := triggMetrString
 	for _, evt := range evalContext.EvalMatches {
 		customData = customData + fmt.Sprintf("%s: %v\n", evt.Metric, evt.Value)
 	}

pkg/services/alerting/notifiers/pagerduty.go

@@ -76,7 +76,7 @@ func (this *PagerdutyNotifier) Notify(evalContext *alerting.EvalContext) error {
 	if evalContext.Rule.State == m.AlertStateOK {
 		eventType = "resolve"
 	}
-	customData := "Triggered metrics:\n\n"
+	customData := triggMetrString
 	for _, evt := range evalContext.EvalMatches {
 		customData = customData + fmt.Sprintf("%s: %v\n", evt.Metric, evt.Value)
 	}

pkg/social/social.go

@@ -46,10 +46,14 @@ func (e *Error) Error() string {
 	return e.s
 }
 
+const (
+	grafanaCom = "grafana_com"
+)
+
 var (
 	SocialBaseUrl = "/login/"
 	SocialMap     = make(map[string]SocialConnector)
-	allOauthes    = []string{"github", "gitlab", "google", "generic_oauth", "grafananet", "grafana_com"}
+	allOauthes    = []string{"github", "gitlab", "google", "generic_oauth", "grafananet", grafanaCom}
 )
 
 func NewOAuthService() {
@@ -82,7 +86,7 @@ func NewOAuthService() {
 		}
 
 		if name == "grafananet" {
-			name = "grafana_com"
+			name = grafanaCom
 		}
 
 		setting.OAuthService.OAuthInfos[name] = info
@@ -159,7 +163,7 @@ func NewOAuthService() {
 			}
 		}
 
-		if name == "grafana_com" {
+		if name == grafanaCom {
 			config = oauth2.Config{
 				ClientID:     info.ClientId,
 				ClientSecret: info.ClientSecret,
@@ -171,7 +175,7 @@ func NewOAuthService() {
 				Scopes:      info.Scopes,
 			}
 
-			SocialMap["grafana_com"] = &SocialGrafanaCom{
+			SocialMap[grafanaCom] = &SocialGrafanaCom{
 				SocialBase: &SocialBase{
 					Config: &config,
 					log:    logger,
@@ -194,7 +198,7 @@ var GetOAuthProviders = func(cfg *setting.Cfg) map[string]bool {
 
 	for _, name := range allOauthes {
 		if name == "grafananet" {
-			name = "grafana_com"
+			name = grafanaCom
 		}
 
 		sec := cfg.Raw.Section("auth." + name)

pkg/tsdb/elasticsearch/response_parser.go

@@ -13,6 +13,19 @@ import (
 	"github.com/grafana/grafana/pkg/tsdb/elasticsearch/client"
 )
 
+const (
+	// Metric types
+	countType         = "count"
+	percentilesType   = "percentiles"
+	extendedStatsType = "extended_stats"
+	// Bucket types
+	dateHistType    = "date_histogram"
+	histogramType   = "histogram"
+	filtersType     = "filters"
+	termsType       = "terms"
+	geohashGridType = "geohash_grid"
+)
+
 type responseParser struct {
 	Responses []*es.SearchResponse
 	Targets   []*Query
@@ -81,7 +94,7 @@ func (rp *responseParser) processBuckets(aggs map[string]interface{}, target *Qu
 		}
 
 		if depth == maxDepth {
-			if aggDef.Type == "date_histogram" {
+			if aggDef.Type == dateHistType {
 				err = rp.processMetrics(esAgg, target, series, props)
 			} else {
 				err = rp.processAggregationDocs(esAgg, aggDef, target, table, props)
@@ -149,7 +162,7 @@ func (rp *responseParser) processMetrics(esAgg *simplejson.Json, target *Query,
 		}
 
 		switch metric.Type {
-		case "count":
+		case countType:
 			newSeries := tsdb.TimeSeries{
 				Tags: make(map[string]string),
 			}
@@ -164,10 +177,10 @@ func (rp *responseParser) processMetrics(esAgg *simplejson.Json, target *Query,
 			for k, v := range props {
 				newSeries.Tags[k] = v
 			}
-			newSeries.Tags["metric"] = "count"
+			newSeries.Tags["metric"] = countType
 			*series = append(*series, &newSeries)
 
-		case "percentiles":
+		case percentilesType:
 			buckets := esAgg.Get("buckets").MustArray()
 			if len(buckets) == 0 {
 				break
@@ -198,7 +211,7 @@ func (rp *responseParser) processMetrics(esAgg *simplejson.Json, target *Query,
 				}
 				*series = append(*series, &newSeries)
 			}
-		case "extended_stats":
+		case extendedStatsType:
 			buckets := esAgg.Get("buckets").MustArray()
 
 			metaKeys := make([]string, 0)
@@ -312,9 +325,9 @@ func (rp *responseParser) processAggregationDocs(esAgg *simplejson.Json, aggDef
 
 		for _, metric := range target.Metrics {
 			switch metric.Type {
-			case "count":
+			case countType:
 				addMetricValue(&values, rp.getMetricName(metric.Type), castToNullFloat(bucket.Get("doc_count")))
-			case "extended_stats":
+			case extendedStatsType:
 				metaKeys := make([]string, 0)
 				meta := metric.Meta.MustMap()
 				for k := range meta {
@@ -366,7 +379,7 @@ func (rp *responseParser) processAggregationDocs(esAgg *simplejson.Json, aggDef
 func (rp *responseParser) trimDatapoints(series *tsdb.TimeSeriesSlice, target *Query) {
 	var histogram *BucketAgg
 	for _, bucketAgg := range target.BucketAggs {
-		if bucketAgg.Type == "date_histogram" {
+		if bucketAgg.Type == dateHistType {
 			histogram = bucketAgg
 			break
 		}

pkg/tsdb/elasticsearch/time_series_query.go

@@ -75,15 +75,15 @@ func (e *timeSeriesQuery) execute() (*tsdb.Response, error) {
 		// iterate backwards to create aggregations bottom-down
 		for _, bucketAgg := range q.BucketAggs {
 			switch bucketAgg.Type {
-			case "date_histogram":
+			case dateHistType:
 				aggBuilder = addDateHistogramAgg(aggBuilder, bucketAgg, from, to)
-			case "histogram":
+			case histogramType:
 				aggBuilder = addHistogramAgg(aggBuilder, bucketAgg)
-			case "filters":
+			case filtersType:
 				aggBuilder = addFiltersAgg(aggBuilder, bucketAgg)
-			case "terms":
+			case termsType:
 				aggBuilder = addTermsAgg(aggBuilder, bucketAgg, q.Metrics)
-			case "geohash_grid":
+			case geohashGridType:
 				aggBuilder = addGeoHashGridAgg(aggBuilder, bucketAgg)
 			}
 		}