util/tracing: test resource schema and environment detection

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

util/tracing/detect/resource_test.go

@@ -5,6 +5,9 @@ import (
 
 	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 func TestResource(t *testing.T) {
@@ -20,9 +23,8 @@ func TestResource(t *testing.T) {
 
 	res := Resource()
 
-	// Should not have an empty schema url. Only happens when
-	// there is a schema conflict.
-	require.NotEmpty(t, res.SchemaURL())
+	// Keep our schema independent of the version used by the OTel SDK.
+	require.Equal(t, schemaURL, res.SchemaURL())
 
 	var found bool
 	for iter := res.Iter(); iter.Next(); {
@@ -36,3 +38,23 @@ func TestResource(t *testing.T) {
 	// No error should have been invoked.
 	require.NoError(t, resourceErr)
 }
+
+func TestResourceWithFromEnv(t *testing.T) {
+	t.Setenv("OTEL_SERVICE_NAME", "buildkit-test")
+	t.Setenv("OTEL_RESOURCE_ATTRIBUTES", "service.name=overridden,custom.attribute=value")
+
+	res, err := resource.New(t.Context(),
+		resource.WithDetectors(serviceNameDetector{}),
+		resource.WithFromEnv(),
+		resource.WithDetectors(telemetrySDK{}),
+	)
+	require.NoError(t, err)
+	require.Equal(t, schemaURL, res.SchemaURL())
+	require.ElementsMatch(t, []attribute.KeyValue{
+		attribute.String(serviceNameKey, "buildkit-test"),
+		attribute.String("custom.attribute", "value"),
+		attribute.String(telemetrySDKNameKey, "opentelemetry"),
+		attribute.String(telemetrySDKLanguageKey, "go"),
+		attribute.String(telemetrySDKVersionKey, sdk.Version()),
+	}, res.Attributes())
+}