First working version

Signed-off-by: Daniel González Lopes <[email protected]>

example.js

@@ -0,0 +1,22 @@
+import { check } from 'k6';
+import remote from 'k6/x/remotewrite';
+
+export let options = {
+    vus: 10,
+    duration: '10s',
+};
+
+const client = new remote.Client({
+    endpoint: "<your-remote-write-endpoint>"
+});
+
+export default function () {
+    let res = client.storeNow({
+        "__name__": `foo_bar${__VU}`,
+        "foo": "bar"
+    }, 12356)
+    check(res, {
+        'is status 200': (r) => r.status === 200,
+    });
+    sleep(1)
+}

go.mod

@@ -0,0 +1,8 @@
+module github.com/dgzlopes/xk6-remote-write
+
+go 1.15
+
+require (
+	github.com/loadimpact/k6 v0.30.0
+	github.com/m3db/prometheus_remote_client_golang v0.4.4
+)

main.go

@@ -0,0 +1,122 @@
+package remotewrite
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log"
+	"strconv"
+	"time"
+
+	"github.com/loadimpact/k6/js/common"
+	"github.com/loadimpact/k6/js/modules"
+	"github.com/loadimpact/k6/lib"
+	"github.com/loadimpact/k6/stats"
+	"github.com/m3db/prometheus_remote_client_golang/promremote"
+)
+
+type dp promremote.Datapoint
+
+// Register the extension on module initialization, available to
+// import from JS as "k6/x/remotewrite".
+func init() {
+	modules.Register("k6/x/remotewrite", new(RemoteWrite))
+}
+
+// RemoteWrite is the k6 extension for interacting with Kubernetes jobs.
+type RemoteWrite struct {
+}
+
+// Client is the Kubernetes client wrapper.
+type Client struct {
+	client promremote.Client
+}
+
+type Config struct {
+	Endpoint  string
+	UserAgent string
+}
+
+type Response struct {
+	Status int
+}
+
+// XClient represents
+func (r *RemoteWrite) XClient(ctxPtr *context.Context, config Config) interface{} {
+	if config.UserAgent == "" {
+		config.UserAgent = "k6-remote-write/0.0.1"
+	}
+	rt := common.GetRuntime(*ctxPtr)
+	cfg := promremote.NewConfig(
+		promremote.WriteURLOption(config.Endpoint),
+		promremote.UserAgent(config.UserAgent),
+	)
+	client, err := promremote.NewClient(cfg)
+	if err != nil {
+		log.Fatal(fmt.Errorf("unable to construct client: %v", err))
+	}
+	return common.Bind(rt, &Client{client: client}, ctxPtr)
+}
+
+// Store a metric
+func (c *Client) Store(ctx context.Context, labels map[string]string, value float64, timestamp time.Time) (Response, error) {
+	var labelList []promremote.Label
+
+	for labelName, labelValue := range labels {
+		labelList = append(labelList, promremote.Label{
+			Name:  labelName,
+			Value: labelValue,
+		})
+	}
+
+	tsList := promremote.TSList{
+		{
+			Labels: labelList,
+			Datapoint: promremote.Datapoint(promremote.Datapoint{
+				Value:     value,
+				Timestamp: timestamp,
+			}),
+		},
+	}
+
+	state := lib.GetState(ctx)
+	err := errors.New("State is nil")
+
+	if state == nil {
+		return Response{}, err
+	}
+
+	stats.PushIfNotDone(ctx, state.Samples, stats.Sample{
+		Metric: RequestsTotal,
+		Time:   time.Time{},
+		Value:  float64(1),
+	})
+
+	start := time.Now()
+	result, writeErr := c.client.WriteTimeSeries(context.Background(), tsList, promremote.WriteOptions{})
+	elapsed := time.Since(start)
+
+	if err := error(writeErr); err != nil {
+		stats.PushIfNotDone(ctx, state.Samples, stats.Sample{
+			Metric: RequestsDuration,
+			Tags:   stats.IntoSampleTags(&map[string]string{"status": strconv.Itoa(writeErr.StatusCode())}),
+			Time:   time.Time{},
+			Value:  float64(elapsed.Milliseconds()),
+		})
+		return Response{Status: writeErr.StatusCode()}, err
+	}
+
+	stats.PushIfNotDone(ctx, state.Samples, stats.Sample{
+		Metric: RequestsDuration,
+		Tags:   stats.IntoSampleTags(&map[string]string{"status": strconv.Itoa(result.StatusCode)}),
+		Time:   time.Time{},
+		Value:  float64(elapsed.Milliseconds()),
+	})
+
+	return Response{Status: result.StatusCode}, nil
+}
+
+// StoreNow a metric
+func (c *Client) StoreNow(ctx context.Context, labels map[string]string, value float64) (Response, error) {
+	return c.Store(ctx, labels, value, time.Now())
+}

stats.go

@@ -0,0 +1,9 @@
+package remotewrite
+
+import "github.com/loadimpact/k6/stats"
+
+var (
+	RequestsTotal = stats.New("remote_write_req_total", stats.Counter)
+
+	RequestsDuration = stats.New("remote_write_req_duration", stats.Trend, stats.Time)
+)