OTel SDK — Go

Instrument a Go application to push metrics directly to xScaler using the OpenTelemetry Go SDK over OTLP/HTTP.

:::warning Required headers Both headers must be passed via otlpmetrichttp.WithHeaders:

• "Authorization": "Bearer <token>"
• "X-Scope-OrgID": "<tenant-id>" :::

---

Install dependencies

go get go.opentelemetry.io/otel \
       go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp \
       go.opentelemetry.io/otel/sdk/metric

---

Setup and instrumentation

package main

import (
    "context"
    "log"
    "time"

    "go.opentelemetry.io/otel"
    "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp"
    "go.opentelemetry.io/otel/sdk/metric"
    "go.opentelemetry.io/otel/sdk/resource"
    semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
)

func main() {
    ctx := context.Background()

    exp, err := otlpmetrichttp.New(ctx,
        otlpmetrichttp.WithEndpoint("euw1-01.m.xscalerlabs.com"),
        otlpmetrichttp.WithURLPath("/otlp/v1/metrics"),
        otlpmetrichttp.WithHeaders(map[string]string{
            "Authorization": "Bearer <token>",
            "X-Scope-OrgID": "<tenant-id>",
        }),
    )
    if err != nil {
        log.Fatalf("failed to create exporter: %v", err)
    }

    res := resource.NewWithAttributes(
        semconv.SchemaURL,
        semconv.ServiceName("my-service"),
        semconv.ServiceVersion("1.0.0"),
    )

    provider := metric.NewMeterProvider(
        metric.WithReader(metric.NewPeriodicReader(exp,
            metric.WithInterval(15*time.Second),
        )),
        metric.WithResource(res),
    )
    defer provider.Shutdown(ctx)
    otel.SetMeterProvider(provider)

    meter := otel.Meter("my-service")

    // Counter example
    counter, err := meter.Int64Counter("http_requests_total",
        metric.WithDescription("Total HTTP requests"),
    )
    if err != nil {
        log.Fatalf("failed to create counter: %v", err)
    }
    counter.Add(ctx, 1)

    // Keep the process alive long enough for one export cycle
    time.Sleep(20 * time.Second)
}

Go SDK endpoint options

The otlpmetrichttp exporter splits the endpoint into two options:

Option	Value	Notes
WithEndpoint	"euw1-01.m.xscalerlabs.com"	Host only, no scheme prefix
WithURLPath	"/otlp/v1/metrics"	Path appended to the host

The SDK uses HTTPS by default when port 443 is resolved. Do not include https:// in WithEndpoint.

---

Load credentials from environment variables

import "os"

exp, err := otlpmetrichttp.New(ctx,
    otlpmetrichttp.WithEndpoint("euw1-01.m.xscalerlabs.com"),
    otlpmetrichttp.WithURLPath("/otlp/v1/metrics"),
    otlpmetrichttp.WithHeaders(map[string]string{
        "Authorization": "Bearer " + os.Getenv("XSCALER_TOKEN"),
        "X-Scope-OrgID": os.Getenv("XSCALER_TENANT_ID"),
    }),
)

---

Graceful shutdown

The defer provider.Shutdown(ctx) call in the example above flushes and exports the final batch before the process exits. In a long-running service, hook this to your signal handler:

sigCh := make(chan os.Signal, 1)
signal.Notify(sigCh, os.Interrupt, syscall.SIGTERM)
<-sigCh
if err := provider.Shutdown(ctx); err != nil {
    log.Printf("error shutting down meter provider: %v", err)
}

---

Troubleshooting

failed to export error at startup

• Verify WithEndpoint is the bare host without scheme: "euw1-01.m.xscalerlabs.com" (not "https://...")
• Verify WithURLPath is "/otlp/v1/metrics"

401 Unauthorized

• The Authorization header value must be "Bearer <token>" — the full string including the Bearer prefix and a space.

400 Bad Request

• The X-Scope-OrgID key is missing from the headers map or misspelled.

Metrics exported but not visible in Grafana

• Allow up to one export interval (15 s) for metrics to appear.
• Verify the tenant ID in X-Scope-OrgID matches the one configured in your Grafana data source.