node_exporter/collector/interrupts.go

119 lines
2.7 KiB
Go

// +build !nointerrupts
package collector
import (
"bufio"
"fmt"
"io"
"os"
"strconv"
"strings"
"github.com/prometheus/client_golang/prometheus"
)
const (
procInterrupts = "/proc/interrupts"
)
var (
interruptsMetric = prometheus.NewCounterVec(
prometheus.CounterOpts{
Namespace: Namespace,
Name: "interrupts",
Help: "Interrupt details from /proc/interrupts.",
},
[]string{"CPU", "type", "info", "devices"},
)
)
type interruptsCollector struct {
config Config
}
func init() {
Factories["interrupts"] = NewInterruptsCollector
}
// Takes a config struct and prometheus registry and returns a new Collector exposing
// interrupts stats
func NewInterruptsCollector(config Config) (Collector, error) {
c := interruptsCollector{
config: config,
}
if _, err := prometheus.RegisterOrGet(interruptsMetric); err != nil {
return nil, err
}
return &c, nil
}
func (c *interruptsCollector) Update() (updates int, err error) {
interrupts, err := getInterrupts()
if err != nil {
return updates, fmt.Errorf("Couldn't get interrupts: %s", err)
}
for name, interrupt := range interrupts {
for cpuNo, value := range interrupt.values {
updates++
fv, err := strconv.ParseFloat(value, 64)
if err != nil {
return updates, fmt.Errorf("Invalid value %s in interrupts: %s", value, err)
}
labels := prometheus.Labels{
"CPU": strconv.Itoa(cpuNo),
"type": name,
"info": interrupt.info,
"devices": interrupt.devices,
}
interruptsMetric.With(labels).Set(fv)
}
}
return updates, err
}
type interrupt struct {
info string
devices string
values []string
}
func getInterrupts() (map[string]interrupt, error) {
file, err := os.Open(procInterrupts)
if err != nil {
return nil, err
}
return parseInterrupts(file)
}
func parseInterrupts(r io.ReadCloser) (map[string]interrupt, error) {
defer r.Close()
interrupts := map[string]interrupt{}
scanner := bufio.NewScanner(r)
if !scanner.Scan() {
return nil, fmt.Errorf("%s empty", procInterrupts)
}
cpuNum := len(strings.Fields(string(scanner.Text()))) // one header per cpu
for scanner.Scan() {
line := scanner.Text()
parts := strings.Fields(string(line))
if len(parts) < cpuNum+2 { // irq + one column per cpu + details,
continue // we ignore ERR and MIS for now
}
intName := parts[0][:len(parts[0])-1] // remove trailing :
intr := interrupt{
values: parts[1:cpuNum],
}
if _, err := strconv.Atoi(intName); err == nil { // numeral interrupt
intr.info = parts[cpuNum+1]
intr.devices = strings.Join(parts[cpuNum+2:], " ")
} else {
intr.info = strings.Join(parts[cpuNum+1:], " ")
}
interrupts[intName] = intr
}
return interrupts, nil
}