update from v3

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

tracer.go

@@ -0,0 +1,128 @@
+package redis
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"strconv"
+
+	rediscmd "github.com/redis/go-redis/extra/rediscmd/v9"
+	goredis "github.com/redis/go-redis/v9"
+	"go.unistack.org/micro/v4/tracer"
+)
+
+func setTracing(rdb goredis.UniversalClient, tr tracer.Tracer, opts ...tracer.SpanOption) {
+	switch rdb := rdb.(type) {
+	case *goredis.Client:
+		opt := rdb.Options()
+		connString := formatDBConnString(opt.Network, opt.Addr)
+		rdb.AddHook(newTracingHook(connString, tr))
+	case *goredis.ClusterClient:
+		rdb.OnNewNode(func(rdb *goredis.Client) {
+			opt := rdb.Options()
+			connString := formatDBConnString(opt.Network, opt.Addr)
+			rdb.AddHook(newTracingHook(connString, tr))
+		})
+	case *goredis.Ring:
+		rdb.OnNewNode(func(rdb *goredis.Client) {
+			opt := rdb.Options()
+			connString := formatDBConnString(opt.Network, opt.Addr)
+			rdb.AddHook(newTracingHook(connString, tr))
+		})
+	}
+}
+
+type tracingHook struct {
+	tr   tracer.Tracer
+	opts []tracer.SpanOption
+}
+
+var _ goredis.Hook = (*tracingHook)(nil)
+
+func newTracingHook(connString string, tr tracer.Tracer, opts ...tracer.SpanOption) *tracingHook {
+	opts = append(opts, tracer.WithSpanKind(tracer.SpanKindClient))
+	if connString != "" {
+		opts = append(opts, tracer.WithSpanLabels("db.connection_string", connString))
+	}
+
+	return &tracingHook{
+		tr:   tr,
+		opts: opts,
+	}
+}
+
+func (h *tracingHook) DialHook(hook goredis.DialHook) goredis.DialHook {
+	return func(ctx context.Context, network, addr string) (net.Conn, error) {
+		/*
+			_, span := h.tr.Start(ctx, "goredis.dial", h.opts...)
+			defer span.Finish()
+		*/
+		conn, err := hook(ctx, network, addr)
+		// recordError(span, err)
+
+		return conn, err
+	}
+}
+
+func (h *tracingHook) ProcessHook(hook goredis.ProcessHook) goredis.ProcessHook {
+	return func(ctx context.Context, cmd goredis.Cmder) error {
+		cmdString := rediscmd.CmdString(cmd)
+		var err error
+
+		switch cmdString {
+		case "cluster slots":
+			break
+		default:
+			_, span := h.tr.Start(ctx, "sdk.database", append(h.opts, tracer.WithSpanLabels("db.statement", cmdString))...)
+			defer func() {
+				recordError(span, err)
+				span.Finish()
+			}()
+		}
+
+		err = hook(ctx, cmd)
+
+		return err
+	}
+}
+
+func (h *tracingHook) ProcessPipelineHook(hook goredis.ProcessPipelineHook) goredis.ProcessPipelineHook {
+	return func(ctx context.Context, cmds []goredis.Cmder) error {
+		_, cmdsString := rediscmd.CmdsString(cmds)
+
+		opts := append(h.opts, tracer.WithSpanLabels(
+			"db.database.num_cmd", strconv.Itoa(len(cmds)),
+			"db.statement", cmdsString,
+		))
+
+		_, span := h.tr.Start(ctx, "sdk.database", opts...)
+		defer span.Finish()
+
+		err := hook(ctx, cmds)
+		recordError(span, err)
+
+		return err
+	}
+}
+
+func setSpanError(ctx context.Context, err error) {
+	if err == nil || err == goredis.Nil {
+		return
+	}
+	if sp, ok := tracer.SpanFromContext(ctx); !ok && sp != nil {
+		sp.SetStatus(tracer.SpanStatusError, err.Error())
+	}
+}
+
+func recordError(span tracer.Span, err error) {
+	if err != nil && err != goredis.Nil {
+		span.SetStatus(tracer.SpanStatusError, err.Error())
+	}
+}
+
+func formatDBConnString(network, addr string) string {
+	if network == "tcp" {
+		network = "redis"
+	}
+	return fmt.Sprintf("%s://%s", network, addr)
+}