Services can now write to pidfiles

service/service.go

@@ -5,6 +5,7 @@ import "os"
 import "log"
 import "time"
 import "hnakra/rotate"
+import "hnakra/daemon"
 import "hnakra/routines"
 
 // Service is capable of managing multiple mounts. It also sets up logging
@@ -12,6 +13,8 @@ import "hnakra/routines"
 type Service struct {
 	ServiceInfo
 	Mounts []Mount
+
+	manager routines.Manager
 }
 
 // NewService provides a shorthand for creating a new service, leaving most
@@ -29,6 +32,8 @@ func NewService (name, description string, mounts ...Mount) *Service {
 // Run runs the mounts within the service, and only exits when all of them have
 // exited. It will automatically start logging to the directory specified by
 // $HNAKRA_LOG_DIR. If that variable is unset, it will just log to stdout.
+// Additionally, if $HNAKRA_PIDFILE is set, it will write the process PID to the
+// file specified by it.
 func (service *Service) Run () error {
 	// set up logging
 	logDir := os.Getenv("HNAKRA_LOG_DIR")
@@ -41,16 +46,28 @@ func (service *Service) Run () error {
 	log.Println("... starting service", service.Name)
 
 	// set up routine manager
-	manager := routines.Manager { RestartDeadline: time.Second * 8 }
-	manager.Routines = make([]routines.Routine, len(service.Mounts))
+	service.manager = routines.Manager { RestartDeadline: time.Second * 8 }
+	service.manager.Routines = make([]routines.Routine, len(service.Mounts))
 	for index, mount := range service.Mounts {
-		manager.Routines[index] = func () error {
+		service.manager.Routines[index] = routines.From (func () error {
 			return mount.Run(service.ServiceInfo)
-		}
+		}, mount.Shutdown)
+	}
+
+	// be a daemon
+	daemon.ShutdownOnSigint(service)
+	pidfile := daemon.PidFile(os.Getenv("HNAKRA_PIDFILE"))
+	if !pidfile.Empty() {
+		err := pidfile.Start()
+		if err != nil { log.Println("!!! could not write pid:", err) }
+		defer func () {
+			err := pidfile.Close()
+			if err != nil { log.Println("!!! could not delete pidfile:", err) }
+		} ()
 	}
 
 	// send it
-	err := manager.Run()
+	err := service.manager.Run()
 	if err != nil { log.Println("XXX", err) }
 	return err
 }
@@ -70,11 +87,5 @@ func (service *Service) Close () (err error) {
 // Shutdown gracefully shuts down each mount in the service. This will cause
 // Run() to exit.
 func (service *Service) Shutdown () (err error) {
-	for _, mount := range service.Mounts {
-		singleErr := mount.Shutdown()
-		if singleErr != nil {
-			err = singleErr
-		}
-	}
-	return
+	return service.manager.Shutdown()
 }