add tracing and refactor some api pkgs

internal/tracing/google/config.go

@@ -0,0 +1,25 @@
+package google
+
+import (
+	"go.opencensus.io/trace"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	"github.com/caos/zitadel/internal/tracing"
+)
+
+type Config struct {
+	ProjectID    string
+	MetricPrefix string
+	Fraction     float64
+}
+
+func (c *Config) NewTracer() error {
+	if !envIsSet() {
+		return status.Error(codes.InvalidArgument, "env not properly set, GOOGLE_APPLICATION_CREDENTIALS is misconfigured or missing")
+	}
+
+	tracing.T = &Tracer{projectID: c.ProjectID, metricPrefix: c.MetricPrefix, sampler: trace.ProbabilitySampler(c.Fraction)}
+
+	return tracing.T.Start()
+}

internal/tracing/google/googletracing.go

@@ -0,0 +1,95 @@
+package google
+
+import (
+	"context"
+	"net/http"
+	"os"
+	"strings"
+
+	"contrib.go.opencensus.io/exporter/stackdriver"
+	"go.opencensus.io/plugin/ocgrpc"
+	"go.opencensus.io/plugin/ochttp"
+	"go.opencensus.io/stats/view"
+	"go.opencensus.io/trace"
+
+	"github.com/caos/zitadel/internal/errors"
+	"github.com/caos/zitadel/internal/tracing"
+)
+
+type Tracer struct {
+	Exporter     *stackdriver.Exporter
+	projectID    string
+	metricPrefix string
+	sampler      trace.Sampler
+}
+
+func (t *Tracer) Start() (err error) {
+	t.Exporter, err = stackdriver.NewExporter(stackdriver.Options{
+		ProjectID:    t.projectID,
+		MetricPrefix: t.metricPrefix,
+	})
+	if err != nil {
+		return errors.ThrowInternal(err, "GOOGL-4dCnX", "unable to start exporter")
+	}
+
+	views := append(ocgrpc.DefaultServerViews, ocgrpc.DefaultClientViews...)
+	views = append(views, ochttp.DefaultClientViews...)
+	views = append(views, ochttp.DefaultServerViews...)
+
+	if err = view.Register(views...); err != nil {
+		return errors.ThrowInternal(err, "GOOGL-Q6L6w", "unable to register view")
+	}
+
+	trace.RegisterExporter(t.Exporter)
+	trace.ApplyConfig(trace.Config{DefaultSampler: t.sampler})
+
+	return nil
+}
+
+func (t *Tracer) Sampler() trace.Sampler {
+	return t.sampler
+}
+
+func (t *Tracer) NewServerInterceptorSpan(ctx context.Context, name string) (context.Context, *tracing.Span) {
+	return t.newSpanFromName(ctx, name, trace.WithSpanKind(trace.SpanKindServer))
+}
+
+func (t *Tracer) NewServerSpan(ctx context.Context, caller string) (context.Context, *tracing.Span) {
+	return t.newSpan(ctx, caller, trace.WithSpanKind(trace.SpanKindServer))
+}
+
+func (t *Tracer) NewClientInterceptorSpan(ctx context.Context, name string) (context.Context, *tracing.Span) {
+	return t.newSpanFromName(ctx, name, trace.WithSpanKind(trace.SpanKindClient))
+}
+
+func (t *Tracer) NewClientSpan(ctx context.Context, caller string) (context.Context, *tracing.Span) {
+	return t.newSpan(ctx, caller, trace.WithSpanKind(trace.SpanKindClient))
+}
+
+func (t *Tracer) NewSpan(ctx context.Context, caller string) (context.Context, *tracing.Span) {
+	return t.newSpan(ctx, caller)
+}
+
+func (t *Tracer) newSpan(ctx context.Context, caller string, options ...trace.StartOption) (context.Context, *tracing.Span) {
+	return t.newSpanFromName(ctx, caller, options...)
+}
+
+func (t *Tracer) newSpanFromName(ctx context.Context, name string, options ...trace.StartOption) (context.Context, *tracing.Span) {
+	ctx, span := trace.StartSpan(ctx, name, options...)
+	return ctx, tracing.CreateSpan(span)
+}
+
+func (t *Tracer) NewSpanHTTP(r *http.Request, caller string) (*http.Request, *tracing.Span) {
+	ctx, span := t.NewSpan(r.Context(), caller)
+	r = r.WithContext(ctx)
+	return r, span
+}
+
+func envIsSet() bool {
+	gAuthCred := os.Getenv("GOOGLE_APPLICATION_CREDENTIALS")
+	return strings.Contains(gAuthCred, ".json")
+}
+
+func (t *Tracer) SetErrStatus(span *trace.Span, code int32, err error, obj ...string) {
+	span.SetStatus(trace.Status{Code: code, Message: err.Error() + strings.Join(obj, ", ")})
+}