remove vendor and code improvement uses latest version

go.mod

@@ -3,8 +3,8 @@ module qvl.io/promplot
 go 1.15
 
 require (
-	github.com/nlopes/slack v0.6.0
 	github.com/prometheus/client_golang v1.9.0 // indirect
 	github.com/prometheus/common v0.15.0
+	github.com/slack-go/slack v0.7.4 // indirect
 	gonum.org/v1/plot v0.8.1
 )

go.sum

@@ -78,6 +78,7 @@ github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V
 github.com/go-logfmt/logfmt v0.5.0/go.mod h1:wCYkCAKZfumFQihp8CzCvQ3paCTfi41vtzG1KdI/P7A=
 github.com/go-sql-driver/mysql v1.4.0/go.mod h1:zAC/RDZ24gD3HViQzih4MyKcchzm+sOG5ZlKdlhCg5w=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
+github.com/go-test/deep v1.0.4/go.mod h1:wGDj63lr65AM2AQyKZd/NYHGb0R+1RLqB8NKt3aSFNA=
 github.com/gogo/googleapis v1.1.0/go.mod h1:gf4bu3Q80BeJ6H1S1vYPm8/ELATdvryBaNFGgqEef3s=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.2.0/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
@@ -117,6 +118,8 @@ github.com/gorilla/mux v1.7.3/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2z
 github.com/gorilla/websocket v0.0.0-20170926233335-4201258b820c/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
 github.com/gorilla/websocket v1.2.0 h1:VJtLvh6VQym50czpZzx07z/kw9EgAxI3x1ZB8taTMQQ=
 github.com/gorilla/websocket v1.2.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
+github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
+github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/grpc-ecosystem/go-grpc-middleware v1.0.1-0.20190118093823-f849b5445de4/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
 github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
 github.com/grpc-ecosystem/grpc-gateway v1.9.5/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
@@ -275,6 +278,8 @@ github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeV
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
 github.com/sirupsen/logrus v1.6.0/go.mod h1:7uNnSEd1DgxDLC74fIahvMZmmYsHGZGEOFrfsX/uA88=
+github.com/slack-go/slack v0.7.4 h1:Z+7CmUDV+ym4lYLA4NNLFIpr3+nDgViHrx8xsuXgrYs=
+github.com/slack-go/slack v0.7.4/go.mod h1:FGqNzJBmxIsZURAxh2a8D21AnOVvvXZvGligs4npPUM=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
 github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
 github.com/soheilhy/cmux v0.1.4/go.mod h1:IM3LyeVVIOuxMH7sFAkER9+bJ4dT7Ms6E4xg4kGIyLM=

promplot/metrics.go

@@ -5,25 +5,27 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/prometheus/client_golang/api/prometheus"
+	"github.com/prometheus/client_golang/api"
+	v1 "github.com/prometheus/client_golang/api/prometheus/v1"
 	"github.com/prometheus/common/model"
 )
 
 // Metrics fetches data from Prometheus.
 func Metrics(server, query string, queryTime time.Time, duration, step time.Duration) (model.Matrix, error) {
-	client, err := prometheus.New(prometheus.Config{Address: server})
+	client, err := api.NewClient(api.Config{Address: server})
 	if err != nil {
-		return nil, fmt.Errorf("failed to create Prometheus client: %v", err)
+		return nil, fmt.Errorf("failed to create prometheus api client: %v", err)
 	}
 
-	api := prometheus.NewQueryAPI(client)
-	value, err := api.QueryRange(context.Background(), query, prometheus.Range{
+	promAPI := v1.NewAPI(client)
+
+	value, _, err := promAPI.QueryRange(context.Background(), query, v1.Range{
 		Start: queryTime.Add(-duration),
 		End:   queryTime,
 		Step:  duration / step,
 	})
 	if err != nil {
-		return nil, fmt.Errorf("failed to query Prometheus: %v", err)
+		return nil, fmt.Errorf("failed to query prometheus api: %v", err)
 	}
 
 	metrics, ok := value.(model.Matrix)

promplot/slack.go

@@ -1,51 +1,51 @@
 package promplot
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
 
-	"github.com/nlopes/slack"
+	"github.com/slack-go/slack"
 )
 
 // Slack posts a file to a Slack channel.
 func Slack(token, channel, title string, plot io.WriterTo) error {
 	api := slack.New(token)
 
-	_, _, err := api.PostMessage(channel, title, slack.PostMessageParameters{
-		Username:  "Promplot",
-		IconEmoji: ":chart_with_upwards_trend:",
-	})
-	if err != nil {
+	if _, _, err := api.PostMessageContext(context.Background(), channel, slack.MsgOptionPostMessageParameters(
+		slack.PostMessageParameters{
+			Username:  "Promplot",
+			IconEmoji: ":chart_with_upwards_trend:",
+		},
+	)); err != nil {
 		return fmt.Errorf("failed to post message: %v", err)
 	}
 
 	f, err := ioutil.TempFile("", "promplot-")
 	if err != nil {
 		return fmt.Errorf("failed to create tmp file: %v", err)
 	}
+
 	defer func() {
-		err = f.Close()
-		if err != nil {
+		if err = f.Close(); err != nil {
 			panic(fmt.Errorf("failed to close tmp file: %v", err))
 		}
-		err := os.Remove(f.Name())
-		if err != nil {
+		if err = os.Remove(f.Name()); err != nil {
 			panic(fmt.Errorf("failed to delete tmp file: %v", err))
 		}
 	}()
-	_, err = plot.WriteTo(f)
-	if err != nil {
+
+	if _, err = plot.WriteTo(f); err != nil {
 		return fmt.Errorf("failed to write plot to file: %v", err)
 	}
 
-	_, err = api.UploadFile(slack.FileUploadParameters{
+	if _, err = api.UploadFile(slack.FileUploadParameters{
 		Title:    title,
 		File:     f.Name(),
 		Channels: []string{channel},
-	})
-	if err != nil {
+	}); err != nil {
 		return fmt.Errorf("failed to upload file: %v", err)
 	}