Add provider.WithTracing decorator mirroring WithMetrics

Co-Authored-By: Claude <noreply@anthropic.com>

internal/provider/tracing.go

@@ -0,0 +1,80 @@
+package provider
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
+
+	"gitea.home.hrajfrisbee.cz/kacerr/egress-proxies-operator/internal/tracing"
+)
+
+// WithTracing wraps a Provider so every call runs in a client span carrying
+// the classified result, mirroring WithMetrics. It goes through
+// tracing.StartSpan, so provider-internal logs (e.g. the gcp provider's
+// context logger) inherit traceID/spanID. Errors pass through unmodified.
+func WithTracing(name string, p Provider, opts ...tracing.Option) Provider {
+	return &traced{name: name, inner: p, tracer: tracing.Tracer(opts...)}
+}
+
+type traced struct {
+	name   string
+	inner  Provider
+	tracer trace.Tracer
+}
+
+func (t *traced) Create(ctx context.Context, req CreateRequest) (string, error) {
+	ctx, span := t.start(ctx, "provider.create")
+	id, err := t.inner.Create(ctx, req)
+	if id != "" {
+		span.SetAttributes(attribute.String("provider.id", id))
+	}
+	t.end(span, err)
+	return id, err
+}
+
+func (t *traced) Get(ctx context.Context, providerID string) (*Instance, error) {
+	ctx, span := t.start(ctx, "provider.get")
+	span.SetAttributes(attribute.String("provider.id", providerID))
+	inst, err := t.inner.Get(ctx, providerID)
+	t.end(span, err)
+	return inst, err
+}
+
+func (t *traced) Delete(ctx context.Context, providerID string) error {
+	ctx, span := t.start(ctx, "provider.delete")
+	span.SetAttributes(attribute.String("provider.id", providerID))
+	err := t.inner.Delete(ctx, providerID)
+	t.end(span, err)
+	return err
+}
+
+func (t *traced) ListByTag(ctx context.Context) ([]Instance, error) {
+	ctx, span := t.start(ctx, "provider.list")
+	instances, err := t.inner.ListByTag(ctx)
+	span.SetAttributes(attribute.Int("provider.instances", len(instances)))
+	t.end(span, err)
+	return instances, err
+}
+
+func (t *traced) start(ctx context.Context, op string) (context.Context, trace.Span) {
+	return tracing.StartSpan(ctx, t.tracer, op,
+		trace.WithSpanKind(trace.SpanKindClient),
+		trace.WithAttributes(attribute.String("provider.name", t.name)))
+}
+
+// end records the taxonomy class and closes the span. ErrNotFound stays Ok:
+// the reconciler polls Get to NotFound during replacement/deletion, so it is
+// an expected answer, not a failure — same reasoning as resultLabel's
+// distinct "not_found" bucket.
+func (t *traced) end(span trace.Span, err error) {
+	span.SetAttributes(attribute.String("provider.result", resultLabel(err)))
+	switch Class(err) {
+	case nil, ErrNotFound:
+		span.SetStatus(codes.Ok, "")
+	default:
+		span.SetStatus(codes.Error, err.Error())
+	}
+	span.End()
+}