add opentelemetry tracing

internal/common/config/http.go

@@ -3,5 +3,4 @@ package config
 type HTTP struct {
 	ListenAddr string `json:"listen_addr"`
 	MountLive  bool   `json:"mount_live"`
-	Engine     string `json:"engine"`
 }

internal/common/config/trace.go

@@ -0,0 +1,6 @@
+package config
+
+type Trace struct {
+	Endpoint   string `json:"endpoint"`
+	LicenseKey string `json:"license_key"`
+}

internal/common/decorator/logging.go

@@ -2,11 +2,24 @@ package decorator
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"log/slog"
+	"strings"
 	"time"
 
 	"git.loyso.art/frx/kurious/internal/common/xcontext"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+)
+
+var (
+	commandAttribute = attribute.Key("command_name")
+	queryAttribute   = attribute.Key("query_name")
+	argsAttribute    = attribute.Key("args")
+
+	apiTracer = otel.Tracer("cq")
 )
 
 type commandLoggingDecorator[T any] struct {
@@ -18,6 +31,17 @@ func (c commandLoggingDecorator[T]) Handle(ctx context.Context, cmd T) (err erro
 	handlerName := getTypeName[T]()
 
 	ctx = xcontext.WithLogFields(ctx, slog.String("handler", handlerName))
+
+	var argsBuilder strings.Builder
+	_ = json.NewEncoder(&argsBuilder).Encode(cmd)
+
+	var span trace.Span
+	ctx, span = apiTracer.Start(ctx, handlerName)
+	span.SetAttributes(
+		commandAttribute.String(handlerName),
+		argsAttribute.String(argsBuilder.String()),
+	)
+
 	xcontext.LogDebug(ctx, c.log, "executing command")
 	start := time.Now()
 
@@ -27,7 +51,9 @@ func (c commandLoggingDecorator[T]) Handle(ctx context.Context, cmd T) (err erro
 			xcontext.LogInfo(ctx, c.log, "command executed successfuly", elapsed)
 		} else {
 			xcontext.LogError(ctx, c.log, "command execution failed", elapsed, slog.Any("err", err))
+			span.RecordError(err)
 		}
+		span.End()
 	}()
 
 	return c.base.Handle(ctx, cmd)
@@ -41,6 +67,17 @@ type queryLoggingDecorator[Q, U any] struct {
 func (q queryLoggingDecorator[Q, U]) Handle(ctx context.Context, query Q) (entity U, err error) {
 	handlerName := getTypeName[Q]()
 	ctx = xcontext.WithLogFields(ctx, slog.String("handler", handlerName))
+
+	var argsBuilder strings.Builder
+	_ = json.NewEncoder(&argsBuilder).Encode(query)
+
+	var span trace.Span
+	ctx, span = apiTracer.Start(ctx, handlerName)
+	span.SetAttributes(
+		queryAttribute.String(handlerName),
+		argsAttribute.String(argsBuilder.String()),
+	)
+
 	xcontext.LogDebug(ctx, q.log, "executing command")
 	start := time.Now()
 
@@ -50,7 +87,10 @@ func (q queryLoggingDecorator[Q, U]) Handle(ctx context.Context, query Q) (entit
 			xcontext.LogInfo(ctx, q.log, "command executed successfuly", elapsed)
 		} else {
 			xcontext.LogError(ctx, q.log, "command execution failed", elapsed, slog.Any("err", err))
+			span.RecordError(err)
 		}
+		now := time.Now()
+		span.End(trace.WithTimestamp(now))
 	}()
 
 	return q.base.Handle(ctx, query)

internal/common/xcontext/log.go

@@ -6,6 +6,16 @@ import (
 )
 
 type ctxLogKey struct{}
+type ctxRequestID struct{}
+
+func WithRequestID(ctx context.Context, requestID string) context.Context {
+	return context.WithValue(ctx, ctxRequestID{}, requestID)
+}
+
+func GetRequestID(ctx context.Context) string {
+	reqid, _ := ctx.Value(ctxRequestID{}).(string)
+	return reqid
+}
 
 type ctxLogAttrStore struct {
 	attrs []slog.Attr

internal/common/xslices/foreach.go

@@ -1,5 +1,10 @@
 package xslices
 
+import (
+	"crypto/rand"
+	"math/big"
+)
+
 func ForEach[T any](items []T, f func(T)) {
 	for _, item := range items {
 		f(item)
@@ -13,3 +18,12 @@ func AsMap[T any, U comparable](items []T, f func(T) U) map[U]struct{} {
 	})
 	return out
 }
+
+func Shuffle[T any](items []T) {
+	maxnum := big.NewInt(int64(len(items)))
+	for i := range items {
+		swapWith, _ := rand.Int(rand.Reader, maxnum)
+		swapWithIdx := int(swapWith.Int64())
+		items[i], items[swapWithIdx] = items[swapWithIdx], items[i]
+	}
+}