windows_exporter/collector/collector.go

107 lines
2.7 KiB
Go

package collector
import (
"strconv"
"strings"
"github.com/leoluk/perflib_exporter/perflib"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/log"
"golang.org/x/sys/windows/registry"
)
// ...
const (
// TODO: Make package-local
Namespace = "wmi"
// Conversion factors
ticksToSecondsScaleFactor = 1 / 1e7
windowsEpoch = 116444736000000000
)
// getWindowsVersion reads the version number of the OS from the Registry
// See https://docs.microsoft.com/en-us/windows/desktop/sysinfo/operating-system-version
func getWindowsVersion() float64 {
k, err := registry.OpenKey(registry.LOCAL_MACHINE, `SOFTWARE\Microsoft\Windows NT\CurrentVersion`, registry.QUERY_VALUE)
if err != nil {
log.Warn("Couldn't open registry", err)
return 0
}
defer func() {
err = k.Close()
if err != nil {
log.Warnf("Failed to close registry key: %v", err)
}
}()
currentv, _, err := k.GetStringValue("CurrentVersion")
if err != nil {
log.Warn("Couldn't open registry to determine current Windows version:", err)
return 0
}
currentv_flt, err := strconv.ParseFloat(currentv, 64)
log.Debugf("Detected Windows version %f\n", currentv_flt)
return currentv_flt
}
type collectorBuilder func() (Collector, error)
var (
builders = make(map[string]collectorBuilder)
perfCounterDependencies = make(map[string]string)
)
func registerCollector(name string, builder collectorBuilder, perfCounterNames ...string) {
builders[name] = builder
perfIndicies := make([]string, 0, len(perfCounterNames))
for _, cn := range perfCounterNames {
perfIndicies = append(perfIndicies, MapCounterToIndex(cn))
}
perfCounterDependencies[name] = strings.Join(perfIndicies, " ")
}
func Available() []string {
cs := make([]string, 0, len(builders))
for c := range builders {
cs = append(cs, c)
}
return cs
}
func Build(collector string) (Collector, error) {
return builders[collector]()
}
func getPerfQuery(collectors []string) string {
parts := make([]string, 0, len(collectors))
for _, c := range collectors {
if p := perfCounterDependencies[c]; p != "" {
parts = append(parts, p)
}
}
return strings.Join(parts, " ")
}
// Collector is the interface a collector has to implement.
type Collector interface {
// Get new metrics and expose them via prometheus registry.
Collect(ctx *ScrapeContext, ch chan<- prometheus.Metric) (err error)
}
type ScrapeContext struct {
perfObjects map[string]*perflib.PerfObject
}
// PrepareScrapeContext creates a ScrapeContext to be used during a single scrape
func PrepareScrapeContext(collectors []string) (*ScrapeContext, error) {
q := getPerfQuery(collectors) // TODO: Memoize
objs, err := getPerflibSnapshot(q)
if err != nil {
return nil, err
}
return &ScrapeContext{objs}, nil
}