Add tracing component-base utilities

Author: dashpole

staging/src/k8s.io/component-base/traces/BUILD

@@ -0,0 +1,31 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["utils.go"],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/component-base/traces",
+    importpath = "k8s.io/component-base/traces",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//vendor/go.opentelemetry.io/otel/api/global:go_default_library",
+        "//vendor/go.opentelemetry.io/otel/exporters/otlp:go_default_library",
+        "//vendor/go.opentelemetry.io/otel/sdk/resource:go_default_library",
+        "//vendor/go.opentelemetry.io/otel/sdk/trace:go_default_library",
+        "//vendor/go.opentelemetry.io/otel/semconv:go_default_library",
+        "//vendor/k8s.io/klog/v2:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

staging/src/k8s.io/component-base/traces/OWNERS

@@ -0,0 +1,8 @@
+# See the OWNERS docs at https://go.k8s.io/owners
+
+approvers:
+- sig-instrumentation-approvers
+reviewers:
+- sig-instrumentation-reviewers
+labels:
+- sig/instrumentation

staging/src/k8s.io/component-base/traces/utils.go

@@ -0,0 +1,45 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package traces
+
+import (
+	"go.opentelemetry.io/otel/api/global"
+	"go.opentelemetry.io/otel/exporters/otlp"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	"go.opentelemetry.io/otel/semconv"
+
+	"k8s.io/klog/v2"
+)
+
+// InitTraces initializes tracing in the component.
+// Components must use the OTLP exporter, but can pass additional exporter
+// options if needed
+func InitTraces(service string, opts ...otlp.ExporterOption) {
+	opts = append(opts, otlp.WithInsecure())
+	exporter, err := otlp.NewExporter(opts...)
+	if err != nil {
+		klog.Fatalf("Failed to create OTLP exporter: %v", err)
+	}
+
+	// Use ParentBased(NeverSample()) to preserve the sampling decision of the
+	// parent, but not start additional spans.
+	tp := sdktrace.NewTracerProvider(
+		sdktrace.WithConfig(sdktrace.Config{
+			DefaultSampler: sdktrace.ParentBased(sdktrace.NeverSample())},
+		),
+		sdktrace.WithBatcher(exporter),
+		sdktrace.WithResource(resource.New(semconv.ServiceNameKey.String(service))))
+	global.SetTracerProvider(tp)
+}