erigon-pulse/metrics/prometheus/prometheus.go
Mark Holt a4cfbe0d56
Heimdall metrics + Metrics HTTP server rationalization (#8094)
This is an update of:

https://github.com/ledgerwatch/erigon/pull/7846

which uses a local fork of victoria metrics to include the changes that
https://github.com/anshalshukla added to the original for we where
using.

It also includes code to address the duplicate metrics issue identified
here:

https://github.com/ledgerwatch/erigon/issues/8053

It has one more associated fix which is to correctly add a metadata
label to counters, these where previously labelled as gauges.

e.g. 

```
# TYPE p2p_peers counter
p2p_peers 0
```
rather than

```
# TYPE p2p_peers gauge
p2p_peers 0
```

---------

Co-authored-by: Anshal Shukla <53994948+anshalshukla@users.noreply.github.com>
Co-authored-by: Anshal Shukla <shukla.anshal85@gmail.com>
2023-08-31 09:04:27 +01:00

84 lines
2.5 KiB
Go

// Copyright 2019 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// Package prometheus exposes go-metrics into a Prometheus format.
package prometheus
import (
"fmt"
"net/http"
"sort"
metrics2 "github.com/VictoriaMetrics/metrics"
"github.com/ledgerwatch/erigon/metrics"
"github.com/ledgerwatch/log/v3"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/expfmt"
)
// Handler returns an HTTP handler which dump metrics in Prometheus format.
func Handler(reg metrics.Registry) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// Gather and pre-sort the metrics to avoid random listings
var names []string
reg.Each(func(name string, i interface{}) {
names = append(names, name)
})
sort.Strings(names)
w.Header().Set("Access-Control-Allow-Origin", "*")
contentType := expfmt.Negotiate(r.Header)
enc := expfmt.NewEncoder(w, contentType)
mf, err := prometheus.DefaultGatherer.Gather()
if err != nil {
return
}
for _, m := range mf {
enc.Encode(m)
}
// Aggregate all the metris into a Prometheus collector
c := newCollector()
c.buff.WriteRune('\n')
for _, name := range names {
i := reg.Get(name)
switch m := i.(type) {
case *metrics2.Counter:
if m.IsGauge() {
c.writeGauge(name, m.Get())
} else {
c.writeCounter(name, m.Get())
}
case *metrics2.Gauge:
c.addGauge(name, m)
case *metrics2.FloatCounter:
c.addFloatCounter(name, m)
case *metrics2.Histogram:
c.addHistogram(name, m)
case *metrics2.Summary:
c.addTimer(name, m)
default:
log.Warn("Unknown Prometheus metric type", "type", fmt.Sprintf("%T", i))
}
}
w.Header().Add("Content-Type", "text/plain")
w.Header().Add("Content-Length", fmt.Sprint(c.buff.Len()))
w.Write(c.buff.Bytes())
})
}