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mirror of https://github.com/open-telemetry/opentelemetry-go.git synced 2024-12-12 10:04:29 +02:00
opentelemetry-go/sdk/trace/sampler_env.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

109 lines
2.9 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 trace // import "go.opentelemetry.io/otel/sdk/trace"
import (
"errors"
"fmt"
"os"
"strconv"
"strings"
)
const (
tracesSamplerKey = "OTEL_TRACES_SAMPLER"
tracesSamplerArgKey = "OTEL_TRACES_SAMPLER_ARG"
samplerAlwaysOn = "always_on"
samplerAlwaysOff = "always_off"
samplerTraceIDRatio = "traceidratio"
samplerParentBasedAlwaysOn = "parentbased_always_on"
samplerParsedBasedAlwaysOff = "parentbased_always_off"
samplerParentBasedTraceIDRatio = "parentbased_traceidratio"
)
type errUnsupportedSampler string
func (e errUnsupportedSampler) Error() string {
return fmt.Sprintf("unsupported sampler: %s", string(e))
}
var (
errNegativeTraceIDRatio = errors.New("invalid trace ID ratio: less than 0.0")
errGreaterThanOneTraceIDRatio = errors.New("invalid trace ID ratio: greater than 1.0")
)
type samplerArgParseError struct {
parseErr error
}
func (e samplerArgParseError) Error() string {
return fmt.Sprintf("parsing sampler argument: %s", e.parseErr.Error())
}
func (e samplerArgParseError) Unwrap() error {
return e.parseErr
}
func samplerFromEnv() (Sampler, error) {
sampler, ok := os.LookupEnv(tracesSamplerKey)
if !ok {
return nil, nil
}
sampler = strings.ToLower(strings.TrimSpace(sampler))
samplerArg, hasSamplerArg := os.LookupEnv(tracesSamplerArgKey)
samplerArg = strings.TrimSpace(samplerArg)
switch sampler {
case samplerAlwaysOn:
return AlwaysSample(), nil
case samplerAlwaysOff:
return NeverSample(), nil
case samplerTraceIDRatio:
if !hasSamplerArg {
return TraceIDRatioBased(1.0), nil
}
return parseTraceIDRatio(samplerArg)
case samplerParentBasedAlwaysOn:
return ParentBased(AlwaysSample()), nil
case samplerParsedBasedAlwaysOff:
return ParentBased(NeverSample()), nil
case samplerParentBasedTraceIDRatio:
if !hasSamplerArg {
return ParentBased(TraceIDRatioBased(1.0)), nil
}
ratio, err := parseTraceIDRatio(samplerArg)
return ParentBased(ratio), err
default:
return nil, errUnsupportedSampler(sampler)
}
}
func parseTraceIDRatio(arg string) (Sampler, error) {
v, err := strconv.ParseFloat(arg, 64)
if err != nil {
return TraceIDRatioBased(1.0), samplerArgParseError{err}
}
if v < 0.0 {
return TraceIDRatioBased(1.0), errNegativeTraceIDRatio
}
if v > 1.0 {
return TraceIDRatioBased(1.0), errGreaterThanOneTraceIDRatio
}
return TraceIDRatioBased(v), nil
}