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// Copyright 2015 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.
//go:build !noconntrack
// +build !noconntrack
package collector
import (
"errors"
"fmt"
"log/slog"
"os"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/procfs"
)
type conntrackCollector struct {
current *prometheus.Desc
limit *prometheus.Desc
found *prometheus.Desc
invalid *prometheus.Desc
ignore *prometheus.Desc
insert *prometheus.Desc
insertFailed *prometheus.Desc
drop *prometheus.Desc
earlyDrop *prometheus.Desc
searchRestart *prometheus.Desc
logger *slog.Logger
}
type conntrackStatistics struct {
found uint64 // Number of searched entries which were successful
invalid uint64 // Number of packets seen which can not be tracked
ignore uint64 // Number of packets seen which are already connected to a conntrack entry
insert uint64 // Number of entries inserted into the list
insertFailed uint64 // Number of entries for which list insertion was attempted but failed (happens if the same entry is already present)
drop uint64 // Number of packets dropped due to conntrack failure. Either new conntrack entry allocation failed, or protocol helper dropped the packet
earlyDrop uint64 // Number of dropped conntrack entries to make room for new ones, if maximum table size was reached
searchRestart uint64 // Number of conntrack table lookups which had to be restarted due to hashtable resizes
}
func init() {
registerCollector("conntrack", defaultEnabled, NewConntrackCollector)
}
// NewConntrackCollector returns a new Collector exposing conntrack stats.
func NewConntrackCollector(logger *slog.Logger) (Collector, error) {
return &conntrackCollector{
current: prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "nf_conntrack_entries"),
"Number of currently allocated flow entries for connection tracking.",
nil, nil,
),
limit: prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "nf_conntrack_entries_limit"),
"Maximum size of connection tracking table.",
nil, nil,
),
found: prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "nf_conntrack_stat_found"),
"Number of searched entries which were successful.",
nil, nil,
),
invalid: prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "nf_conntrack_stat_invalid"),
"Number of packets seen which can not be tracked.",
nil, nil,
),
ignore: prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "nf_conntrack_stat_ignore"),
"Number of packets seen which are already connected to a conntrack entry.",
nil, nil,
),
insert: prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "nf_conntrack_stat_insert"),
"Number of entries inserted into the list.",
nil, nil,
),
insertFailed: prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "nf_conntrack_stat_insert_failed"),
"Number of entries for which list insertion was attempted but failed.",
nil, nil,
),
drop: prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "nf_conntrack_stat_drop"),
"Number of packets dropped due to conntrack failure.",
nil, nil,
),
earlyDrop: prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "nf_conntrack_stat_early_drop"),
"Number of dropped conntrack entries to make room for new ones, if maximum table size was reached.",
nil, nil,
),
searchRestart: prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "nf_conntrack_stat_search_restart"),
"Number of conntrack table lookups which had to be restarted due to hashtable resizes.",
nil, nil,
),
logger: logger,
}, nil
}
func (c *conntrackCollector) Update(ch chan<- prometheus.Metric) error {
value, err := readUintFromFile(procFilePath("sys/net/netfilter/nf_conntrack_count"))
if err != nil {
return c.handleErr(err)
}
ch <- prometheus.MustNewConstMetric(
c.current, prometheus.GaugeValue, float64(value))
value, err = readUintFromFile(procFilePath("sys/net/netfilter/nf_conntrack_max"))
if err != nil {
return c.handleErr(err)
}
ch <- prometheus.MustNewConstMetric(
c.limit, prometheus.GaugeValue, float64(value))
conntrackStats, err := getConntrackStatistics()
if err != nil {
return c.handleErr(err)
}
ch <- prometheus.MustNewConstMetric(
c.found, prometheus.GaugeValue, float64(conntrackStats.found))
ch <- prometheus.MustNewConstMetric(
c.invalid, prometheus.GaugeValue, float64(conntrackStats.invalid))
ch <- prometheus.MustNewConstMetric(
c.ignore, prometheus.GaugeValue, float64(conntrackStats.ignore))
ch <- prometheus.MustNewConstMetric(
c.insert, prometheus.GaugeValue, float64(conntrackStats.insert))
ch <- prometheus.MustNewConstMetric(
c.insertFailed, prometheus.GaugeValue, float64(conntrackStats.insertFailed))
ch <- prometheus.MustNewConstMetric(
c.drop, prometheus.GaugeValue, float64(conntrackStats.drop))
ch <- prometheus.MustNewConstMetric(
c.earlyDrop, prometheus.GaugeValue, float64(conntrackStats.earlyDrop))
ch <- prometheus.MustNewConstMetric(
c.searchRestart, prometheus.GaugeValue, float64(conntrackStats.searchRestart))
return nil
}
func (c *conntrackCollector) handleErr(err error) error {
if errors.Is(err, os.ErrNotExist) {
c.logger.Debug("conntrack probably not loaded")
return ErrNoData
}
return fmt.Errorf("failed to retrieve conntrack stats: %w", err)
}
func getConntrackStatistics() (*conntrackStatistics, error) {
c := conntrackStatistics{}
fs, err := procfs.NewFS(*procPath)
if err != nil {
return nil, fmt.Errorf("failed to open procfs: %w", err)
}
connStats, err := fs.ConntrackStat()
if err != nil {
return nil, err
}
for _, connStat := range connStats {
c.found += connStat.Found
c.invalid += connStat.Invalid
c.ignore += connStat.Ignore
c.insert += connStat.Insert
c.insertFailed += connStat.InsertFailed
c.drop += connStat.Drop
c.earlyDrop += connStat.EarlyDrop
c.searchRestart += connStat.SearchRestart
}
return &c, nil
}
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