windows_exporter/pkg/initiate/initiate.go

73 lines
1.7 KiB
Go

// Package initiate allows us to initiate Time Sensitive components (Like registering the windows service) as early as possible in the startup process
package initiate
import (
"fmt"
"os"
"golang.org/x/sys/windows/svc"
"golang.org/x/sys/windows/svc/eventlog"
)
const (
serviceName = "windows_exporter"
)
type windowsExporterService struct {
stopCh chan<- bool
}
var logger *eventlog.Log
func (s *windowsExporterService) Execute(_ []string, r <-chan svc.ChangeRequest, changes chan<- svc.Status) (ssec bool, errno uint32) {
const cmdsAccepted = svc.AcceptStop | svc.AcceptShutdown
changes <- svc.Status{State: svc.StartPending}
changes <- svc.Status{State: svc.Running, Accepts: cmdsAccepted}
loop:
for {
select {
case c := <-r:
switch c.Cmd {
case svc.Interrogate:
changes <- c.CurrentStatus
case svc.Stop, svc.Shutdown:
_ = logger.Info(100, "Service Stop Received")
changes <- svc.Status{State: svc.StopPending}
break loop
default:
_ = logger.Error(102, fmt.Sprintf("unexpected control request #%d", c))
}
}
}
s.stopCh <- true
return
}
var StopCh = make(chan bool)
func init() {
isService, err := svc.IsWindowsService()
if err != nil {
logger, err = eventlog.Open("windows_exporter")
if err != nil {
os.Exit(2)
}
_ = logger.Error(102, fmt.Sprintf("Failed to detect service: %v", err))
os.Exit(1)
}
if isService {
logger, err = eventlog.Open("windows_exporter")
if err != nil {
os.Exit(2)
}
_ = logger.Info(100, "Attempting to start exporter service")
go func() {
err = svc.Run(serviceName, &windowsExporterService{stopCh: StopCh})
if err != nil {
_ = logger.Error(102, fmt.Sprintf("Failed to start service: %v", err))
}
}()
}
}