open-nomad/vendor/github.com/armon/go-metrics/datadog/dogstatsd.go
2016-10-15 10:49:33 +02:00

126 lines
3.7 KiB
Go

package datadog
import (
"fmt"
"strings"
"github.com/DataDog/datadog-go/statsd"
)
// DogStatsdSink provides a MetricSink that can be used
// with a dogstatsd server. It utilizes the Dogstatsd client at github.com/DataDog/datadog-go/statsd
type DogStatsdSink struct {
client *statsd.Client
hostName string
propagateHostname bool
}
// NewDogStatsdSink is used to create a new DogStatsdSink with sane defaults
func NewDogStatsdSink(addr string, hostName string) (*DogStatsdSink, error) {
client, err := statsd.New(addr)
if err != nil {
return nil, err
}
sink := &DogStatsdSink{
client: client,
hostName: hostName,
propagateHostname: false,
}
return sink, nil
}
// SetTags sets common tags on the Dogstatsd Client that will be sent
// along with all dogstatsd packets.
// Ref: http://docs.datadoghq.com/guides/dogstatsd/#tags
func (s *DogStatsdSink) SetTags(tags []string) {
s.client.Tags = tags
}
// EnableHostnamePropagation forces a Dogstatsd `host` tag with the value specified by `s.HostName`
// Since the go-metrics package has its own mechanism for attaching a hostname to metrics,
// setting the `propagateHostname` flag ensures that `s.HostName` overrides the host tag naively set by the DogStatsd server
func (s *DogStatsdSink) EnableHostNamePropagation() {
s.propagateHostname = true
}
func (s *DogStatsdSink) flattenKey(parts []string) string {
joined := strings.Join(parts, ".")
return strings.Map(func(r rune) rune {
switch r {
case ':':
fallthrough
case ' ':
return '_'
default:
return r
}
}, joined)
}
func (s *DogStatsdSink) parseKey(key []string) ([]string, []string) {
// Since DogStatsd supports dimensionality via tags on metric keys, this sink's approach is to splice the hostname out of the key in favor of a `host` tag
// The `host` tag is either forced here, or set downstream by the DogStatsd server
var tags []string
hostName := s.hostName
//Splice the hostname out of the key
for i, el := range key {
if el == hostName {
key = append(key[:i], key[i+1:]...)
}
}
if s.propagateHostname {
tags = append(tags, fmt.Sprintf("host:%s", hostName))
}
return key, tags
}
// Implementation of methods in the MetricSink interface
func (s *DogStatsdSink) SetGauge(key []string, val float32) {
s.SetGaugeWithTags(key, val, []string{})
}
func (s *DogStatsdSink) IncrCounter(key []string, val float32) {
s.IncrCounterWithTags(key, val, []string{})
}
// EmitKey is not implemented since DogStatsd does not provide a metric type that holds an
// arbitrary number of values
func (s *DogStatsdSink) EmitKey(key []string, val float32) {
}
func (s *DogStatsdSink) AddSample(key []string, val float32) {
s.AddSampleWithTags(key, val, []string{})
}
// The following ...WithTags methods correspond to Datadog's Tag extension to Statsd.
// http://docs.datadoghq.com/guides/dogstatsd/#tags
func (s *DogStatsdSink) SetGaugeWithTags(key []string, val float32, tags []string) {
flatKey, tags := s.getFlatkeyAndCombinedTags(key, tags)
rate := 1.0
s.client.Gauge(flatKey, float64(val), tags, rate)
}
func (s *DogStatsdSink) IncrCounterWithTags(key []string, val float32, tags []string) {
flatKey, tags := s.getFlatkeyAndCombinedTags(key, tags)
rate := 1.0
s.client.Count(flatKey, int64(val), tags, rate)
}
func (s *DogStatsdSink) AddSampleWithTags(key []string, val float32, tags []string) {
flatKey, tags := s.getFlatkeyAndCombinedTags(key, tags)
rate := 1.0
s.client.TimeInMilliseconds(flatKey, float64(val), tags, rate)
}
func (s *DogStatsdSink) getFlatkeyAndCombinedTags(key []string, tags []string) (flattenedKey string, combinedTags []string) {
key, hostTags := s.parseKey(key)
flatKey := s.flattenKey(key)
tags = append(tags, hostTags...)
return flatKey, tags
}