add OTLP traces & metrics transports

Author: endorama

internal/loadgen/eventhandler/otlp.go

@@ -0,0 +1,72 @@
+// Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+// or more contributor license agreements. Licensed under the Elastic License 2.0;
+// you may not use this file except in compliance with the Elastic License 2.0.
+
+package eventhandler
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+type OTLPTransport struct {
+	client  *http.Client
+	headers http.Header
+	url     string
+}
+
+func (o *OTLPTransport) SendEvents(ctx context.Context, r io.Reader, ignoreErrs bool) error {
+	req, err := http.NewRequestWithContext(ctx, "POST", o.url, r)
+	if err != nil {
+		return err
+	}
+	req.Header = o.headers
+
+	res, err := o.client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+
+	if !ignoreErrs {
+		switch res.StatusCode / 100 {
+		case 4:
+			return fmt.Errorf("unexpected client error: %d", res.StatusCode)
+		case 5:
+			return fmt.Errorf("unexpected server error: %d", res.StatusCode)
+		}
+	}
+
+	return nil
+}
+
+func newOTLPTransport(c *http.Client, srvURL, u, apiKey string, headers map[string]string) *OTLPTransport {
+	h := make(http.Header)
+	h.Set("Content-Encoding", "deflate")
+	h.Set("Content-Type", "application/x-json")
+	h.Set("Authorization", "ApiKey "+apiKey)
+
+	for name, header := range headers {
+		h.Set(name, header)
+	}
+
+	return &OTLPTransport{
+		client:  c,
+		url:     srvURL + u,
+		headers: h,
+	}
+}
+
+func NewOTLPLogsTransport() {
+	panic("not implemented")
+}
+
+func NewOTLPMetricsTransport(c *http.Client, srvURL, apiKey string, headers map[string]string) Transport {
+	return newOTLPTransport(c, srvURL, "/v1/metrics", apiKey, headers)
+}
+
+func NewOTLPTracesTransport(c *http.Client, srvURL, apiKey string, headers map[string]string) Transport {
+	return newOTLPTransport(c, srvURL, "/v1/traces", apiKey, headers)
+}