1 files changed, 280 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/graphite/bridge.go b/vendor/github.com/prometheus/client_golang/prometheus/graphite/bridge.go
new file mode 100644
index 000000000..11533374b
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/graphite/bridge.go
@@ -0,0 +1,280 @@
+// Copyright 2016 The Prometheus 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 graphite provides a bridge to push Prometheus metrics to a Graphite
+// server.
+package graphite
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"sort"
+	"time"
+
+	"github.com/prometheus/common/expfmt"
+	"github.com/prometheus/common/model"
+	"golang.org/x/net/context"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	defaultInterval       = 15 * time.Second
+	millisecondsPerSecond = 1000
+)
+
+// HandlerErrorHandling defines how a Handler serving metrics will handle
+// errors.
+type HandlerErrorHandling int
+
+// These constants cause handlers serving metrics to behave as described if
+// errors are encountered.
+const (
+	// Ignore errors and try to push as many metrics to Graphite as possible.
+	ContinueOnError HandlerErrorHandling = iota
+
+	// Abort the push to Graphite upon the first error encountered.
+	AbortOnError
+)
+
+// Config defines the Graphite bridge config.
+type Config struct {
+	// The url to push data to. Required.
+	URL string
+
+	// The prefix for the pushed Graphite metrics. Defaults to empty string.
+	Prefix string
+
+	// The interval to use for pushing data to Graphite. Defaults to 15 seconds.
+	Interval time.Duration
+
+	// The timeout for pushing metrics to Graphite. Defaults to 15 seconds.
+	Timeout time.Duration
+
+	// The Gatherer to use for metrics. Defaults to prometheus.DefaultGatherer.
+	Gatherer prometheus.Gatherer
+
+	// The logger that messages are written to. Defaults to no logging.
+	Logger Logger
+
+	// ErrorHandling defines how errors are handled. Note that errors are
+	// logged regardless of the configured ErrorHandling provided Logger
+	// is not nil.
+	ErrorHandling HandlerErrorHandling
+}
+
+// Bridge pushes metrics to the configured Graphite server.
+type Bridge struct {
+	url      string
+	prefix   string
+	interval time.Duration
+	timeout  time.Duration
+
+	errorHandling HandlerErrorHandling
+	logger        Logger
+
+	g prometheus.Gatherer
+}
+
+// Logger is the minimal interface Bridge needs for logging. Note that
+// log.Logger from the standard library implements this interface, and it is
+// easy to implement by custom loggers, if they don't do so already anyway.
+type Logger interface {
+	Println(v ...interface{})
+}
+
+// NewBridge returns a pointer to a new Bridge struct.
+func NewBridge(c *Config) (*Bridge, error) {
+	b := &Bridge{}
+
+	if c.URL == "" {
+		return nil, errors.New("missing URL")
+	}
+	b.url = c.URL
+
+	if c.Gatherer == nil {
+		b.g = prometheus.DefaultGatherer
+	} else {
+		b.g = c.Gatherer
+	}
+
+	if c.Logger != nil {
+		b.logger = c.Logger
+	}
+
+	if c.Prefix != "" {
+		b.prefix = c.Prefix
+	}
+
+	var z time.Duration
+	if c.Interval == z {
+		b.interval = defaultInterval
+	} else {
+		b.interval = c.Interval
+	}
+
+	if c.Timeout == z {
+		b.timeout = defaultInterval
+	} else {
+		b.timeout = c.Timeout
+	}
+
+	b.errorHandling = c.ErrorHandling
+
+	return b, nil
+}
+
+// Run starts the event loop that pushes Prometheus metrics to Graphite at the
+// configured interval.
+func (b *Bridge) Run(ctx context.Context) {
+	ticker := time.NewTicker(b.interval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			if err := b.Push(); err != nil && b.logger != nil {
+				b.logger.Println("error pushing to Graphite:", err)
+			}
+		case <-ctx.Done():
+			return
+		}
+	}
+}
+
+// Push pushes Prometheus metrics to the configured Graphite server.
+func (b *Bridge) Push() error {
+	mfs, err := b.g.Gather()
+	if err != nil || len(mfs) == 0 {
+		switch b.errorHandling {
+		case AbortOnError:
+			return err
+		case ContinueOnError:
+			if b.logger != nil {
+				b.logger.Println("continue on error:", err)
+			}
+		default:
+			panic("unrecognized error handling value")
+		}
+	}
+
+	conn, err := net.DialTimeout("tcp", b.url, b.timeout)
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+
+	return writeMetrics(conn, mfs, b.prefix, model.Now())
+}
+
+func writeMetrics(w io.Writer, mfs []*dto.MetricFamily, prefix string, now model.Time) error {
+	vec, err := expfmt.ExtractSamples(&expfmt.DecodeOptions{
+		Timestamp: now,
+	}, mfs...)
+	if err != nil {
+		return err
+	}
+
+	buf := bufio.NewWriter(w)
+	for _, s := range vec {
+		if err := writeSanitized(buf, prefix); err != nil {
+			return err
+		}
+		if err := buf.WriteByte('.'); err != nil {
+			return err
+		}
+		if err := writeMetric(buf, s.Metric); err != nil {
+			return err
+		}
+		if _, err := fmt.Fprintf(buf, " %g %d\n", s.Value, int64(s.Timestamp)/millisecondsPerSecond); err != nil {
+			return err
+		}
+		if err := buf.Flush(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func writeMetric(buf *bufio.Writer, m model.Metric) error {
+	metricName, hasName := m[model.MetricNameLabel]
+	numLabels := len(m) - 1
+	if !hasName {
+		numLabels = len(m)
+	}
+
+	labelStrings := make([]string, 0, numLabels)
+	for label, value := range m {
+		if label != model.MetricNameLabel {
+			labelStrings = append(labelStrings, fmt.Sprintf("%s %s", string(label), string(value)))
+		}
+	}
+
+	var err error
+	switch numLabels {
+	case 0:
+		if hasName {
+			return writeSanitized(buf, string(metricName))
+		}
+	default:
+		sort.Strings(labelStrings)
+		if err = writeSanitized(buf, string(metricName)); err != nil {
+			return err
+		}
+		for _, s := range labelStrings {
+			if err = buf.WriteByte('.'); err != nil {
+				return err
+			}
+			if err = writeSanitized(buf, s); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func writeSanitized(buf *bufio.Writer, s string) error {
+	prevUnderscore := false
+
+	for _, c := range s {
+		c = replaceInvalidRune(c)
+		if c == '_' {
+			if prevUnderscore {
+				continue
+			}
+			prevUnderscore = true
+		} else {
+			prevUnderscore = false
+		}
+		if _, err := buf.WriteRune(c); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func replaceInvalidRune(c rune) rune {
+	if c == ' ' {
+		return '.'
+	}
+	if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_' || c == ':' || (c >= '0' && c <= '9')) {
+		return '_'
+	}
+	return c
+}