mirror of https://github.com/knative/pkg.git
58 lines
1.8 KiB
Go
58 lines
1.8 KiB
Go
/*
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Copyright 2019 The Knative Authors
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package tracing
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import (
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"net/http"
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"go.opencensus.io/plugin/ochttp"
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"go.opencensus.io/trace"
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"k8s.io/apimachinery/pkg/util/sets"
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"knative.dev/pkg/tracing/propagation/tracecontextb3"
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)
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var (
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// neverSample forcibly turns off sampling.
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neverSample = trace.StartOptions{
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Sampler: trace.NeverSample(),
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}
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// underlyingSampling uses the underlying sampling configuration (normally via the ConfigMap
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// config-tracing).
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underlyingSampling = trace.StartOptions{}
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// HTTPSpanMiddleware is an http.Handler middleware to create spans for the HTTP endpoint.
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HTTPSpanMiddleware = HTTPSpanIgnoringPaths()
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)
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// HTTPSpanIgnoringPaths is an http.Handler middleware to create spans for the HTTP
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// endpoint, not sampling any request whose path is in pathsToIgnore.
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func HTTPSpanIgnoringPaths(pathsToIgnore ...string) func(http.Handler) http.Handler {
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pathsToIgnoreSet := sets.NewString(pathsToIgnore...)
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return func(next http.Handler) http.Handler {
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return &ochttp.Handler{
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Handler: next,
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GetStartOptions: func(r *http.Request) trace.StartOptions {
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if pathsToIgnoreSet.Has(r.URL.Path) {
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return neverSample
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}
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return underlyingSampling
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},
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Propagation: tracecontextb3.TraceContextEgress,
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}
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}
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}
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