wrappers: introduce timer services

Signed-off-by: Maciej Borzecki <maciej.zenon.borzecki@canonical.com>

wrappers/export_test.go

@@ -27,6 +27,7 @@ import (
 var (
 	// services
 	GenerateSnapServiceFile = generateSnapServiceFile
+	GenerateSnapTimerFile   = generateSnapTimerFile
 
 	// desktop
 	SanitizeDesktopFile    = sanitizeDesktopFile

wrappers/services.go

@@ -65,10 +65,16 @@ func stopService(sysd systemd.Systemd, app *snap.AppInfo, inter interacter) erro
 	serviceName := app.ServiceName()
 	tout := serviceStopTimeout(app)
 
-	socketErrors := []error{}
+	stopErrors := []error{}
 	for _, socket := range app.Sockets {
 		if err := sysd.Stop(filepath.Base(socket.File()), tout); err != nil {
-			socketErrors = append(socketErrors, err)
+			stopErrors = append(stopErrors, err)
+		}
+	}
+
+	if app.Timer != nil {
+		if err := sysd.Stop(filepath.Base(app.Timer.File()), tout); err != nil {
+			stopErrors = append(stopErrors, err)
 		}
 	}
 
@@ -84,8 +90,8 @@ func stopService(sysd systemd.Systemd, app *snap.AppInfo, inter interacter) erro
 
 	}
 
-	if len(socketErrors) > 0 {
-		return socketErrors[0]
+	if len(stopErrors) > 0 {
+		return stopErrors[0]
 	}
 
 	return nil
@@ -115,9 +121,15 @@ func StartServices(apps []*snap.AppInfo, inter interacter) (err error) {
 					inter.Notify(fmt.Sprintf("While trying to disable previously enabled socket service %q: %v", socketService, e))
 				}
 			}
+			if app.Timer != nil {
+				timerService := filepath.Base(app.Timer.File())
+				if e := sysd.Disable(timerService); e != nil {
+					inter.Notify(fmt.Sprintf("While trying to disable previously enabled timer service %q: %v", timerService, e))
+				}
+			}
 		}(app)
 
-		if len(app.Sockets) == 0 {
+		if len(app.Sockets) == 0 && app.Timer == nil {
 			services = append(services, app.ServiceName())
 		}
 
@@ -133,6 +145,18 @@ func StartServices(apps []*snap.AppInfo, inter interacter) (err error) {
 			}
 		}
 
+		if app.Timer != nil {
+			timerService := filepath.Base(app.Timer.File())
+			// enable the timer
+			if err := sysd.Enable(timerService); err != nil {
+				return err
+			}
+
+			if err := sysd.Start(timerService); err != nil {
+				return err
+			}
+		}
+
 	}
 
 	if len(services) > 0 {
@@ -200,6 +224,17 @@ func AddSnapServices(s *snap.Info, inter interacter) (err error) {
 			written = append(written, path)
 		}
 
+		if app.Timer != nil {
+			content := generateSnapTimerFile(app)
+			path := app.Timer.File()
+			os.MkdirAll(filepath.Dir(path), 0755)
+			if err := osutil.AtomicWriteFile(path, content, 0644, 0); err != nil {
+				return err
+			}
+			written = append(written, path)
+			continue
+		}
+
 		svcName := app.ServiceName()
 		if err := sysd.Enable(svcName); err != nil {
 			return err
@@ -459,6 +494,52 @@ func renderListenStream(socket *snap.SocketInfo) string {
 	return strings.Replace(listenStream, "$SNAP_COMMON", snap.CommonDataDir(), -1)
 }
 
+func generateSnapTimerFile(app *snap.AppInfo) []byte {
+	timerTemplate := `[Unit]
+# Auto-generated, DO NOT EDIT
+Description=Timer {{.TimerName}} for snap application {{.App.Snap.Name}}.{{.App.Name}}
+Requires={{.MountUnit}}
+After={{.MountUnit}}
+X-Snappy=yes
+
+[Timer]
+Unit={{.ServiceFileName}}
+{{ range .Schedules }}OnCalendar={{ . }}
+{{- end }}
+
+[Install]
+WantedBy={{.TimersTarget}}
+`
+	var templateOut bytes.Buffer
+	t := template.Must(template.New("timer-wrapper").Parse(timerTemplate))
+
+	schedules, _ := generateOnCalendarSchedules(app.Timer.Timer)
+
+	wrapperData := struct {
+		App             *snap.AppInfo
+		ServiceFileName string
+		TimersTarget    string
+		TimerName       string
+		MountUnit       string
+		Schedules       []string
+	}{
+		App:             app,
+		ServiceFileName: filepath.Base(app.ServiceFile()),
+		TimersTarget:    systemd.TimersTarget,
+		TimerName:       app.Name,
+		MountUnit:       filepath.Base(systemd.MountUnitPath(app.Snap.MountDir())),
+		Schedules:       schedules,
+	}
+
+	if err := t.Execute(&templateOut, wrapperData); err != nil {
+		// this can never happen, except we forget a variable
+		logger.Panicf("Unable to execute template: %v", err)
+	}
+
+	return templateOut.Bytes()
+
+}
+
 func makeAbbrevWeekdays(start time.Weekday, end time.Weekday) []string {
 	out := make([]string, 0, 7)
 	for w := start; w%7 != (end + 1); w++ {

wrappers/services_gen_test.go

@@ -322,6 +322,89 @@ WantedBy=multi-user.target
 	c.Assert(string(generatedWrapper), Equals, expectedService)
 }
 
+func (s *servicesWrapperGenSuite) TestServiceTimerUnit(c *C) {
+	const expectedServiceFmt = `[Unit]
+# Auto-generated, DO NOT EDIT
+Description=Timer app for snap application snap.app
+Requires=%s-snap-44.mount
+After=%s-snap-44.mount
+X-Snappy=yes
+
+[Timer]
+Unit=snap.snap.app.service
+OnCalendar=*-*-* 10:00
+
+[Install]
+WantedBy=timers.target
+`
+
+	expectedService := fmt.Sprintf(expectedServiceFmt, mountUnitPrefix, mountUnitPrefix)
+	service := &snap.AppInfo{
+		Snap: &snap.Info{
+			SuggestedName: "snap",
+			Version:       "0.3.4",
+			SideInfo:      snap.SideInfo{Revision: snap.R(44)},
+		},
+		Name:        "app",
+		Command:     "bin/foo start",
+		Daemon:      "simple",
+		StopTimeout: timeout.DefaultTimeout,
+		Timer: &snap.TimerInfo{
+			Timer: "10:00-12:00",
+		},
+	}
+	service.Timer.App = service
+
+	generatedWrapper := wrappers.GenerateSnapTimerFile(service)
+
+	c.Logf("timer: \n%v\n", string(generatedWrapper))
+	c.Assert(string(generatedWrapper), Equals, expectedService)
+}
+
+func (s *servicesWrapperGenSuite) TestServiceTimerServiceUnit(c *C) {
+	const expectedServiceFmt = `[Unit]
+# Auto-generated, DO NOT EDIT
+Description=Service for snap application snap.app
+Requires=%s-snap-44.mount
+Wants=network-online.target
+After=%s-snap-44.mount network-online.target
+X-Snappy=yes
+
+[Service]
+ExecStart=/usr/bin/snap run --timer="10:00-12:00,,mon,23:00~01:00/2" snap.app
+SyslogIdentifier=snap.app
+Restart=%s
+WorkingDirectory=/var/snap/snap/44
+TimeoutStopSec=30
+Type=%s
+
+[Install]
+WantedBy=multi-user.target
+`
+
+	expectedService := fmt.Sprintf(expectedServiceFmt, mountUnitPrefix, mountUnitPrefix, "on-failure", "simple")
+	service := &snap.AppInfo{
+		Snap: &snap.Info{
+			SuggestedName: "snap",
+			Version:       "0.3.4",
+			SideInfo:      snap.SideInfo{Revision: snap.R(44)},
+		},
+		Name:        "app",
+		Command:     "bin/foo start",
+		Daemon:      "simple",
+		StopTimeout: timeout.DefaultTimeout,
+		Timer: &snap.TimerInfo{
+			Timer: "10:00-12:00,,mon,23:00~01:00/2",
+		},
+	}
+
+	generatedWrapper, err := wrappers.GenerateSnapServiceFile(service)
+	c.Assert(err, IsNil)
+
+	c.Logf("service: \n%v\n", string(generatedWrapper))
+	c.Assert(string(generatedWrapper), Equals, expectedService)
+}
+
 func (s *servicesWrapperGenSuite) TestTimerGenerateSchedules(c *C) {
 	systemdAnalyzePath, _ := exec.LookPath("systemd-analyze")