feat(otel): add OpenTelemetry configuration and sampling logic

config.example.yaml

@@ -105,3 +105,7 @@ worker:
 # linuxDo
 linuxDo:
   api_key: "<LINUX_DO_API_KEY>"
+
+# OpenTelemetry 配置
+otel:
+  sampling_rate: 0.1  # 采样率 0.0-1.0

internal/config/model.go

@@ -35,6 +35,7 @@ type configModel struct {
 	Worker     workerConfig     `mapstructure:"worker"`
 	ClickHouse clickHouseConfig `mapstructure:"clickhouse"`
 	LinuxDo    linuxDoConfig    `mapstructure:"linuxdo"`
+	Otel       otelConfig       `mapstructure:"otel"`
 }
 
 // appConfig 应用基本配置
@@ -141,3 +142,8 @@ type workerConfig struct {
 type linuxDoConfig struct {
 	ApiKey string `mapstructure:"api_key"`
 }
+
+// otelConfig OpenTelemetry 配置
+type otelConfig struct {
+	SamplingRate float64 `mapstructure:"sampling_rate"`
+}

internal/otel_trace/sampler.go

@@ -0,0 +1,39 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2025 linux.do
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package otel_trace
+
+import (
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+)
+
+// ParentBasedErrorAwareSampler 创建父级感知的概率采样器
+// - 如果父 Span 已采样，则子 Span 也采样
+// - 如果父 Span 未采样，则子 Span 也不采样
+// - 如果是根 Span，按 samplingRate 概率采样
+func ParentBasedErrorAwareSampler(samplingRate float64) sdktrace.Sampler {
+	return sdktrace.ParentBased(
+		sdktrace.TraceIDRatioBased(samplingRate),
+	)
+}

internal/otel_trace/trace_provider.go

@@ -26,6 +26,7 @@ package otel_trace
 
 import (
 	"context"
+
 	"github.com/linux-do/cdk/internal/config"
 	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
 	"go.opentelemetry.io/otel/sdk/resource"
@@ -56,6 +57,7 @@ func newTracerProvider() (*sdktrace.TracerProvider, error) {
 	tracerProvider := sdktrace.NewTracerProvider(
 		sdktrace.WithBatcher(traceExporter),
 		sdktrace.WithResource(r),
+		sdktrace.WithSampler(ParentBasedErrorAwareSampler(config.Config.Otel.SamplingRate)),
 	)
 	return tracerProvider, nil
 }