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mirror of https://github.com/open-telemetry/opentelemetry-go.git synced 2025-01-05 22:54:18 +02:00
opentelemetry-go/example/passthrough/handler/handler.go
Tyler Yahn 1f5b159161
Use already enabled revive linter and add depguard (#2883)
* Refactor golangci-lint conf

Order settings alphabetically.

* Add revive settings to golangci conf

* Check blank imports

* Check bool-literal-in-expr

* Check constant-logical-expr

* Check context-as-argument

* Check context-key-type

* Check deep-exit

* Check defer

* Check dot-imports

* Check duplicated-imports

* Check early-return

* Check empty-block

* Check empty-lines

* Check error-naming

* Check error-return

* Check error-strings

* Check errorf

* Stop ignoring context first arg in tests

* Check exported comments

* Check flag-parameter

* Check identical branches

* Check if-return

* Check increment-decrement

* Check indent-error-flow

* Check deny list of go imports

* Check import shadowing

* Check package comments

* Check range

* Check range val in closure

* Check range val address

* Check redefines builtin id

* Check string-format

* Check struct tag

* Check superfluous else

* Check time equal

* Check var naming

* Check var declaration

* Check unconditional recursion

* Check unexported return

* Check unhandled errors

* Check unnecessary stmt

* Check unnecessary break

* Check waitgroup by value

* Exclude deep-exit check in example*_test.go files
2022-05-19 15:15:07 -05:00

78 lines
2.7 KiB
Go

// Copyright The OpenTelemetry 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 handler // import "go.opentelemetry.io/otel/example/passthrough/handler"
import (
"context"
"log"
"net/http"
"time"
"go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/propagation"
"go.opentelemetry.io/otel/trace"
)
// Handler is a minimal implementation of the handler and client from
// go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp for demonstration purposes.
// It handles an incoming http request, and makes an outgoing http request.
type Handler struct {
propagators propagation.TextMapPropagator
tracer trace.Tracer
next func(r *http.Request)
}
// New returns a new Handler that will trace requests before handing them off
// to next.
func New(next func(r *http.Request)) *Handler {
// Like most instrumentation packages, this handler defaults to using the
// global progatators and tracer providers.
return &Handler{
propagators: otel.GetTextMapPropagator(),
tracer: otel.Tracer("examples/passthrough/handler"),
next: next,
}
}
// HandleHTTPReq mimics what an instrumented http server does.
func (h *Handler) HandleHTTPReq(r *http.Request) {
ctx := h.propagators.Extract(r.Context(), propagation.HeaderCarrier(r.Header))
var span trace.Span
log.Println("The \"handle passthrough request\" span should NOT be recorded, because it is recorded by a TracerProvider not backed by the SDK.")
ctx, span = h.tracer.Start(ctx, "handle passthrough request")
defer span.End()
// Pretend to do work
time.Sleep(time.Second)
h.makeOutgoingRequest(ctx)
}
// makeOutgoingRequest mimics what an instrumented http client does.
func (h *Handler) makeOutgoingRequest(ctx context.Context) {
// make a new http request
r, err := http.NewRequest("", "", nil)
if err != nil {
panic(err)
}
log.Println("The \"make outgoing request from passthrough\" span should NOT be recorded, because it is recorded by a TracerProvider not backed by the SDK.")
ctx, span := h.tracer.Start(ctx, "make outgoing request from passthrough")
defer span.End()
r = r.WithContext(ctx)
h.propagators.Inject(ctx, propagation.HeaderCarrier(r.Header))
h.next(r)
}