Resources
A resource represents the entity producing telemetry as resource attributes. For example, a process producing telemetry that is running in a container on Kubernetes has a process name, a pod name, a namespace, and possibly a deployment name. All four of these attributes can be included in the resource.
In your observability backend, you can use resource information to better investigate interesting behavior. For example, if your trace or metrics data indicate latency in your system, you can narrow it down to a specific container, pod, or Kubernetes deployment.
Resources should be assigned to a tracer provider at its initialization, and are created much like attributes:
res := resource.NewWithAttributes(
semconv.SchemaURL,
semconv.ServiceNameKey.String("myService"),
semconv.ServiceVersionKey.String("1.0.0"),
semconv.ServiceInstanceIDKey.String("abcdef12345"),
)
provider := sdktrace.NewTracerProvider(
...
sdktrace.WithResource(res),
)
Note the use of the semconv package to provide
conventional names for resource
attributes. This helps ensure that consumers of telemetry produced with these
semantic conventions can easily discover relevant attributes and understand
their meaning.
Resources can also be detected automatically through resource.Detector
implementations. These Detectors may discover information about the currently
running process, the operating system it is running on, the cloud provider
hosting that operating system instance, or any number of other resource
attributes.
res, err := resource.New(
context.Background(),
resource.WithFromEnv(), // Discover and provide attributes from OTEL_RESOURCE_ATTRIBUTES and OTEL_SERVICE_NAME environment variables.
resource.WithTelemetrySDK(), // Discover and provide information about the OpenTelemetry SDK used.
resource.WithProcess(), // Discover and provide process information.
resource.WithOS(), // Discover and provide OS information.
resource.WithContainer(), // Discover and provide container information.
resource.WithHost(), // Discover and provide host information.
resource.WithAttributes(attribute.String("foo", "bar")), // Add custom resource attributes.
// resource.WithDetectors(thirdparty.Detector{}), // Bring your own external Detector implementation.
)
if errors.Is(err, resource.ErrPartialResource) || errors.Is(err, resource.ErrSchemaURLConflict) {
log.Println(err) // Log non-fatal issues.
} else if err != nil {
log.Fatalln(err) // The error may be fatal.
}