opentelemetry-go-contrib/exporters/metric/dogstatsd/dogstatsd.go

132 lines
3.8 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 dogstatsd // import "go.opentelemetry.io/contrib/exporters/metric/dogstatsd"
import (
"bytes"
"time"
"go.opentelemetry.io/contrib/exporters/metric/dogstatsd/internal/statsd"
"go.opentelemetry.io/otel/api/global"
export "go.opentelemetry.io/otel/sdk/export/metric"
"go.opentelemetry.io/otel/sdk/metric/controller/push"
"go.opentelemetry.io/otel/sdk/metric/processor/basic"
"go.opentelemetry.io/otel/sdk/metric/selector/simple"
"go.opentelemetry.io/otel/sdk/resource"
)
type (
Config = statsd.Config
// Exporter implements a dogstatsd-format statsd exporter,
// which encodes label sets as independent fields in the
// output.
//
// TODO: find a link for this syntax. It's been copied out of
// code, not a specification:
//
// https://github.com/stripe/veneur/blob/master/sinks/datadog/datadog.go
Exporter struct {
*statsd.Exporter
labelEncoder *LabelEncoder
}
)
var (
_ export.Exporter = &Exporter{}
)
// NewRawExporter returns a new Dogstatsd-syntax exporter for use in a pipeline.
func NewRawExporter(config Config) (*Exporter, error) {
exp := &Exporter{
labelEncoder: NewLabelEncoder(),
}
var err error
exp.Exporter, err = statsd.NewExporter(config, exp)
return exp, err
}
// InstallNewPipeline instantiates a NewExportPipeline and registers it globally.
// Typically called as:
//
// pipeline, err := dogstatsd.InstallNewPipeline(dogstatsd.Config{...})
// if err != nil {
// ...
// }
// defer pipeline.Stop()
// ... Done
func InstallNewPipeline(config Config) (*push.Controller, error) {
controller, err := NewExportPipeline(config, push.WithPeriod(time.Minute))
if err != nil {
return controller, err
}
global.SetMeterProvider(controller.Provider())
return controller, err
}
// NewExportPipeline sets up a complete export pipeline with the recommended setup,
// chaining a NewRawExporter into the recommended selectors and batchers.
func NewExportPipeline(config Config, opts ...push.Option) (*push.Controller, error) {
exporter, err := NewRawExporter(config)
if err != nil {
return nil, err
}
// Use arrays for Values and sums for everything else
selector := simple.NewWithExactDistribution()
// The basic processor ensures that the exporter sees the full
// set of labels as dogstatsd tags.
processor := basic.New(selector, exporter)
pusher := push.New(processor, exporter, opts...)
pusher.Start()
return pusher, nil
}
// AppendName is part of the stats-internal adapter interface.
func (*Exporter) AppendName(rec export.Record, buf *bytes.Buffer) {
_, _ = buf.WriteString(rec.Descriptor().Name())
}
// AppendTags is part of the stats-internal adapter interface.
func (e *Exporter) AppendTags(rec export.Record, res *resource.Resource, buf *bytes.Buffer) {
rencoded := res.Encoded(e.labelEncoder)
lencoded := rec.Labels().Encoded(e.labelEncoder)
// Note: We do not de-duplicate tag-keys between resources and
// event labels here. Instead, include resources first so
// that the receiver can apply OTel's last-value-wins
// semantcis, if desired.
rlen := len(rencoded)
llen := len(lencoded)
if rlen == 0 && llen == 0 {
return
}
buf.WriteString("|#")
_, _ = buf.WriteString(rencoded)
if rlen != 0 && llen != 0 {
buf.WriteRune(',')
}
_, _ = buf.WriteString(lencoded)
}