node_exporter/collector/vmstat_linux.go

87 lines
2.1 KiB
Go

// 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.
//go:build !novmstat
// +build !novmstat
package collector
import (
"bufio"
"fmt"
"os"
"regexp"
"strconv"
"strings"
"github.com/alecthomas/kingpin/v2"
"github.com/go-kit/log"
"github.com/prometheus/client_golang/prometheus"
)
const (
vmStatSubsystem = "vmstat"
)
var (
vmStatFields = kingpin.Flag("collector.vmstat.fields", "Regexp of fields to return for vmstat collector.").Default("^(oom_kill|pgpg|pswp|pg.*fault).*").String()
)
type vmStatCollector struct {
fieldPattern *regexp.Regexp
logger log.Logger
}
func init() {
registerCollector("vmstat", defaultEnabled, NewvmStatCollector)
}
// NewvmStatCollector returns a new Collector exposing vmstat stats.
func NewvmStatCollector(logger log.Logger) (Collector, error) {
pattern := regexp.MustCompile(*vmStatFields)
return &vmStatCollector{
fieldPattern: pattern,
logger: logger,
}, nil
}
func (c *vmStatCollector) Update(ch chan<- prometheus.Metric) error {
file, err := os.Open(procFilePath("vmstat"))
if err != nil {
return err
}
defer file.Close()
scanner := bufio.NewScanner(file)
for scanner.Scan() {
parts := strings.Fields(scanner.Text())
value, err := strconv.ParseFloat(parts[1], 64)
if err != nil {
return err
}
if !c.fieldPattern.MatchString(parts[0]) {
continue
}
ch <- prometheus.MustNewConstMetric(
prometheus.NewDesc(
prometheus.BuildFQName(namespace, vmStatSubsystem, parts[0]),
fmt.Sprintf("/proc/vmstat information field %s.", parts[0]),
nil, nil),
prometheus.UntypedValue,
value,
)
}
return scanner.Err()
}