otelx

This package simplifies the process of configuring and initializing OpenTelemetry tracing.

Environment variables

It includes a function for reading configuration values from environment variables. Below is a table describing the available environment variables:

TRACING_RESOURCE_ATTRIBUTES can be extended with other environment variables:

TRACING_RESOURCE_ATTRIBUTES=attr.key=val,from.another.var=$ANOTHER_VAR

Usage example

    cfg, err := otelx.ConfigFromEnv()

// optionally rewrite parameters
cfg.Resource.ServiceName = "My Service"
cfg.Communication.ExportMethod = otelx.ExportMethodGRPC

// this will create and set tracer provider, exporter and propagators based on the given configuration
// every component could be configured or overridden by specifying options
telemetry, err := otelx.Setup(
context.Background(),
cfg,
otelx.WithResourceAttributes(attribute.String("my.custom.param", "test")),
)

if err != nil {
fmt.Println("failed to setup OpenTelemetry: ", err)
return
}
// ...

You can use custom detectors. For this, they need to be registered in advance using the otelx.RegisterDetector function.

There are three ways to add detectors:

• Through the TRACING_RESOURCE_DETECTORS environment variable, where the detector names should be listed separated by commas.
• You can add the detector name after loading the configuration.
• You can directly set a detector instance using the WithResourceDetectors option.

package example

import (
	"context"
	"github.com/velmie/x/svc/otelx"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/sdk/resource"
)

type MyCustomDetector struct{}

func (m MyCustomDetector) Detect(ctx context.Context) (*resource.Resource, error) {
	return resource.NewWithAttributes(
		semconv.SchemaURL,
		attribute.String("my.custom.attribute1", "hello"),
		attribute.Int("my.custom.attribute2", 42),
	), nil
}

// ... 

func main() {
	cfg, err := otelx.ConfigFromEnv()

	otelx.RegisterDetector("my.custom_detector", &MyCustomDetector{})

	// it's possible to specify directly which detectors to use
	cfg.Resource.Detectors = append(cfg.Resource.Detectors, "my.custom_detector")

	otelx.Setup(context.Background(), cfg) // alternatively you may specify it directly using otelx.WithResourceDetectors(&MyCustomDetector{})
}