mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-11-18 12:20:24 +00:00
528 lines
13 KiB
Go
528 lines
13 KiB
Go
// Copyright 2020 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 expfmt
|
|
|
|
import (
|
|
"bufio"
|
|
"bytes"
|
|
"fmt"
|
|
"io"
|
|
"math"
|
|
"strconv"
|
|
"strings"
|
|
|
|
"github.com/golang/protobuf/ptypes"
|
|
"github.com/prometheus/common/model"
|
|
|
|
dto "github.com/prometheus/client_model/go"
|
|
)
|
|
|
|
// MetricFamilyToOpenMetrics converts a MetricFamily proto message into the
|
|
// OpenMetrics text format and writes the resulting lines to 'out'. It returns
|
|
// the number of bytes written and any error encountered. The output will have
|
|
// the same order as the input, no further sorting is performed. Furthermore,
|
|
// this function assumes the input is already sanitized and does not perform any
|
|
// sanity checks. If the input contains duplicate metrics or invalid metric or
|
|
// label names, the conversion will result in invalid text format output.
|
|
//
|
|
// This function fulfills the type 'expfmt.encoder'.
|
|
//
|
|
// Note that OpenMetrics requires a final `# EOF` line. Since this function acts
|
|
// on individual metric families, it is the responsibility of the caller to
|
|
// append this line to 'out' once all metric families have been written.
|
|
// Conveniently, this can be done by calling FinalizeOpenMetrics.
|
|
//
|
|
// The output should be fully OpenMetrics compliant. However, there are a few
|
|
// missing features and peculiarities to avoid complications when switching from
|
|
// Prometheus to OpenMetrics or vice versa:
|
|
//
|
|
// - Counters are expected to have the `_total` suffix in their metric name. In
|
|
// the output, the suffix will be truncated from the `# TYPE` and `# HELP`
|
|
// line. A counter with a missing `_total` suffix is not an error. However,
|
|
// its type will be set to `unknown` in that case to avoid invalid OpenMetrics
|
|
// output.
|
|
//
|
|
// - No support for the following (optional) features: `# UNIT` line, `_created`
|
|
// line, info type, stateset type, gaugehistogram type.
|
|
//
|
|
// - The size of exemplar labels is not checked (i.e. it's possible to create
|
|
// exemplars that are larger than allowed by the OpenMetrics specification).
|
|
//
|
|
// - The value of Counters is not checked. (OpenMetrics doesn't allow counters
|
|
// with a `NaN` value.)
|
|
func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int, err error) {
|
|
name := in.GetName()
|
|
if name == "" {
|
|
return 0, fmt.Errorf("MetricFamily has no name: %s", in)
|
|
}
|
|
|
|
// Try the interface upgrade. If it doesn't work, we'll use a
|
|
// bufio.Writer from the sync.Pool.
|
|
w, ok := out.(enhancedWriter)
|
|
if !ok {
|
|
b := bufPool.Get().(*bufio.Writer)
|
|
b.Reset(out)
|
|
w = b
|
|
defer func() {
|
|
bErr := b.Flush()
|
|
if err == nil {
|
|
err = bErr
|
|
}
|
|
bufPool.Put(b)
|
|
}()
|
|
}
|
|
|
|
var (
|
|
n int
|
|
metricType = in.GetType()
|
|
shortName = name
|
|
)
|
|
if metricType == dto.MetricType_COUNTER && strings.HasSuffix(shortName, "_total") {
|
|
shortName = name[:len(name)-6]
|
|
}
|
|
|
|
// Comments, first HELP, then TYPE.
|
|
if in.Help != nil {
|
|
n, err = w.WriteString("# HELP ")
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
n, err = w.WriteString(shortName)
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
err = w.WriteByte(' ')
|
|
written++
|
|
if err != nil {
|
|
return
|
|
}
|
|
n, err = writeEscapedString(w, *in.Help, true)
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
err = w.WriteByte('\n')
|
|
written++
|
|
if err != nil {
|
|
return
|
|
}
|
|
}
|
|
n, err = w.WriteString("# TYPE ")
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
n, err = w.WriteString(shortName)
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
switch metricType {
|
|
case dto.MetricType_COUNTER:
|
|
if strings.HasSuffix(name, "_total") {
|
|
n, err = w.WriteString(" counter\n")
|
|
} else {
|
|
n, err = w.WriteString(" unknown\n")
|
|
}
|
|
case dto.MetricType_GAUGE:
|
|
n, err = w.WriteString(" gauge\n")
|
|
case dto.MetricType_SUMMARY:
|
|
n, err = w.WriteString(" summary\n")
|
|
case dto.MetricType_UNTYPED:
|
|
n, err = w.WriteString(" unknown\n")
|
|
case dto.MetricType_HISTOGRAM:
|
|
n, err = w.WriteString(" histogram\n")
|
|
default:
|
|
return written, fmt.Errorf("unknown metric type %s", metricType.String())
|
|
}
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
// Finally the samples, one line for each.
|
|
for _, metric := range in.Metric {
|
|
switch metricType {
|
|
case dto.MetricType_COUNTER:
|
|
if metric.Counter == nil {
|
|
return written, fmt.Errorf(
|
|
"expected counter in metric %s %s", name, metric,
|
|
)
|
|
}
|
|
// Note that we have ensured above that either the name
|
|
// ends on `_total` or that the rendered type is
|
|
// `unknown`. Therefore, no `_total` must be added here.
|
|
n, err = writeOpenMetricsSample(
|
|
w, name, "", metric, "", 0,
|
|
metric.Counter.GetValue(), 0, false,
|
|
metric.Counter.Exemplar,
|
|
)
|
|
case dto.MetricType_GAUGE:
|
|
if metric.Gauge == nil {
|
|
return written, fmt.Errorf(
|
|
"expected gauge in metric %s %s", name, metric,
|
|
)
|
|
}
|
|
n, err = writeOpenMetricsSample(
|
|
w, name, "", metric, "", 0,
|
|
metric.Gauge.GetValue(), 0, false,
|
|
nil,
|
|
)
|
|
case dto.MetricType_UNTYPED:
|
|
if metric.Untyped == nil {
|
|
return written, fmt.Errorf(
|
|
"expected untyped in metric %s %s", name, metric,
|
|
)
|
|
}
|
|
n, err = writeOpenMetricsSample(
|
|
w, name, "", metric, "", 0,
|
|
metric.Untyped.GetValue(), 0, false,
|
|
nil,
|
|
)
|
|
case dto.MetricType_SUMMARY:
|
|
if metric.Summary == nil {
|
|
return written, fmt.Errorf(
|
|
"expected summary in metric %s %s", name, metric,
|
|
)
|
|
}
|
|
for _, q := range metric.Summary.Quantile {
|
|
n, err = writeOpenMetricsSample(
|
|
w, name, "", metric,
|
|
model.QuantileLabel, q.GetQuantile(),
|
|
q.GetValue(), 0, false,
|
|
nil,
|
|
)
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
}
|
|
n, err = writeOpenMetricsSample(
|
|
w, name, "_sum", metric, "", 0,
|
|
metric.Summary.GetSampleSum(), 0, false,
|
|
nil,
|
|
)
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
n, err = writeOpenMetricsSample(
|
|
w, name, "_count", metric, "", 0,
|
|
0, metric.Summary.GetSampleCount(), true,
|
|
nil,
|
|
)
|
|
case dto.MetricType_HISTOGRAM:
|
|
if metric.Histogram == nil {
|
|
return written, fmt.Errorf(
|
|
"expected histogram in metric %s %s", name, metric,
|
|
)
|
|
}
|
|
infSeen := false
|
|
for _, b := range metric.Histogram.Bucket {
|
|
n, err = writeOpenMetricsSample(
|
|
w, name, "_bucket", metric,
|
|
model.BucketLabel, b.GetUpperBound(),
|
|
0, b.GetCumulativeCount(), true,
|
|
b.Exemplar,
|
|
)
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
if math.IsInf(b.GetUpperBound(), +1) {
|
|
infSeen = true
|
|
}
|
|
}
|
|
if !infSeen {
|
|
n, err = writeOpenMetricsSample(
|
|
w, name, "_bucket", metric,
|
|
model.BucketLabel, math.Inf(+1),
|
|
0, metric.Histogram.GetSampleCount(), true,
|
|
nil,
|
|
)
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
}
|
|
n, err = writeOpenMetricsSample(
|
|
w, name, "_sum", metric, "", 0,
|
|
metric.Histogram.GetSampleSum(), 0, false,
|
|
nil,
|
|
)
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
n, err = writeOpenMetricsSample(
|
|
w, name, "_count", metric, "", 0,
|
|
0, metric.Histogram.GetSampleCount(), true,
|
|
nil,
|
|
)
|
|
default:
|
|
return written, fmt.Errorf(
|
|
"unexpected type in metric %s %s", name, metric,
|
|
)
|
|
}
|
|
written += n
|
|
if err != nil {
|
|
return
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
// FinalizeOpenMetrics writes the final `# EOF\n` line required by OpenMetrics.
|
|
func FinalizeOpenMetrics(w io.Writer) (written int, err error) {
|
|
return w.Write([]byte("# EOF\n"))
|
|
}
|
|
|
|
// writeOpenMetricsSample writes a single sample in OpenMetrics text format to
|
|
// w, given the metric name, the metric proto message itself, optionally an
|
|
// additional label name with a float64 value (use empty string as label name if
|
|
// not required), the value (optionally as float64 or uint64, determined by
|
|
// useIntValue), and optionally an exemplar (use nil if not required). The
|
|
// function returns the number of bytes written and any error encountered.
|
|
func writeOpenMetricsSample(
|
|
w enhancedWriter,
|
|
name, suffix string,
|
|
metric *dto.Metric,
|
|
additionalLabelName string, additionalLabelValue float64,
|
|
floatValue float64, intValue uint64, useIntValue bool,
|
|
exemplar *dto.Exemplar,
|
|
) (int, error) {
|
|
var written int
|
|
n, err := w.WriteString(name)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
if suffix != "" {
|
|
n, err = w.WriteString(suffix)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
}
|
|
n, err = writeOpenMetricsLabelPairs(
|
|
w, metric.Label, additionalLabelName, additionalLabelValue,
|
|
)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
err = w.WriteByte(' ')
|
|
written++
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
if useIntValue {
|
|
n, err = writeUint(w, intValue)
|
|
} else {
|
|
n, err = writeOpenMetricsFloat(w, floatValue)
|
|
}
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
if metric.TimestampMs != nil {
|
|
err = w.WriteByte(' ')
|
|
written++
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
// TODO(beorn7): Format this directly without converting to a float first.
|
|
n, err = writeOpenMetricsFloat(w, float64(*metric.TimestampMs)/1000)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
}
|
|
if exemplar != nil {
|
|
n, err = writeExemplar(w, exemplar)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
}
|
|
err = w.WriteByte('\n')
|
|
written++
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
return written, nil
|
|
}
|
|
|
|
// writeOpenMetricsLabelPairs works like writeOpenMetrics but formats the float
|
|
// in OpenMetrics style.
|
|
func writeOpenMetricsLabelPairs(
|
|
w enhancedWriter,
|
|
in []*dto.LabelPair,
|
|
additionalLabelName string, additionalLabelValue float64,
|
|
) (int, error) {
|
|
if len(in) == 0 && additionalLabelName == "" {
|
|
return 0, nil
|
|
}
|
|
var (
|
|
written int
|
|
separator byte = '{'
|
|
)
|
|
for _, lp := range in {
|
|
err := w.WriteByte(separator)
|
|
written++
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
n, err := w.WriteString(lp.GetName())
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
n, err = w.WriteString(`="`)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
n, err = writeEscapedString(w, lp.GetValue(), true)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
err = w.WriteByte('"')
|
|
written++
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
separator = ','
|
|
}
|
|
if additionalLabelName != "" {
|
|
err := w.WriteByte(separator)
|
|
written++
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
n, err := w.WriteString(additionalLabelName)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
n, err = w.WriteString(`="`)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
n, err = writeOpenMetricsFloat(w, additionalLabelValue)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
err = w.WriteByte('"')
|
|
written++
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
}
|
|
err := w.WriteByte('}')
|
|
written++
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
return written, nil
|
|
}
|
|
|
|
// writeExemplar writes the provided exemplar in OpenMetrics format to w. The
|
|
// function returns the number of bytes written and any error encountered.
|
|
func writeExemplar(w enhancedWriter, e *dto.Exemplar) (int, error) {
|
|
written := 0
|
|
n, err := w.WriteString(" # ")
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
n, err = writeOpenMetricsLabelPairs(w, e.Label, "", 0)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
err = w.WriteByte(' ')
|
|
written++
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
n, err = writeOpenMetricsFloat(w, e.GetValue())
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
if e.Timestamp != nil {
|
|
err = w.WriteByte(' ')
|
|
written++
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
ts, err := ptypes.Timestamp((*e).Timestamp)
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
// TODO(beorn7): Format this directly from components of ts to
|
|
// avoid overflow/underflow and precision issues of the float
|
|
// conversion.
|
|
n, err = writeOpenMetricsFloat(w, float64(ts.UnixNano())/1e9)
|
|
written += n
|
|
if err != nil {
|
|
return written, err
|
|
}
|
|
}
|
|
return written, nil
|
|
}
|
|
|
|
// writeOpenMetricsFloat works like writeFloat but appends ".0" if the resulting
|
|
// number would otherwise contain neither a "." nor an "e".
|
|
func writeOpenMetricsFloat(w enhancedWriter, f float64) (int, error) {
|
|
switch {
|
|
case f == 1:
|
|
return w.WriteString("1.0")
|
|
case f == 0:
|
|
return w.WriteString("0.0")
|
|
case f == -1:
|
|
return w.WriteString("-1.0")
|
|
case math.IsNaN(f):
|
|
return w.WriteString("NaN")
|
|
case math.IsInf(f, +1):
|
|
return w.WriteString("+Inf")
|
|
case math.IsInf(f, -1):
|
|
return w.WriteString("-Inf")
|
|
default:
|
|
bp := numBufPool.Get().(*[]byte)
|
|
*bp = strconv.AppendFloat((*bp)[:0], f, 'g', -1, 64)
|
|
if !bytes.ContainsAny(*bp, "e.") {
|
|
*bp = append(*bp, '.', '0')
|
|
}
|
|
written, err := w.Write(*bp)
|
|
numBufPool.Put(bp)
|
|
return written, err
|
|
}
|
|
}
|
|
|
|
// writeUint is like writeInt just for uint64.
|
|
func writeUint(w enhancedWriter, u uint64) (int, error) {
|
|
bp := numBufPool.Get().(*[]byte)
|
|
*bp = strconv.AppendUint((*bp)[:0], u, 10)
|
|
written, err := w.Write(*bp)
|
|
numBufPool.Put(bp)
|
|
return written, err
|
|
}
|