snap: make AppInfo.ActivatesOn a slice of SlotInfos

Also implicitly bind the named slot to the app.

interfaces/builtin/dbus.go

@@ -356,8 +356,8 @@ func (iface *dbusInterface) DBusPermanentSlot(spec *dbus.Specification, slot *sn
 
 	// handle activatable services
 	for _, app := range slot.Apps {
-		for _, slotName := range app.ActivatesOn {
-			if slotName == slot.Name {
+		for _, s := range app.ActivatesOn {
+			if s == slot {
 				err = spec.AddService(bus, name, app)
 				if err != nil {
 					return err
@@ -444,8 +444,8 @@ func (iface *dbusInterface) BeforePrepareSlot(slot *snap.SlotInfo) error {
 
 	var apps []*snap.AppInfo
 	for _, app := range slot.Apps {
-		for _, slotName := range app.ActivatesOn {
-			if slotName == slot.Name {
+		for _, s := range app.ActivatesOn {
+			if s == slot {
 				apps = append(apps, app)
 				break
 			}

interfaces/builtin/dbus_test.go

@@ -137,14 +137,10 @@ apps:
   test-session-activatable-provider:
     daemon: dbus
     daemon-scope: user
-    slots:
-    - test-session-activatable-slot
     activates-on:
     - test-session-activatable-slot
   test-system-activatable-provider:
     daemon: dbus
-    slots:
-    - test-system-activatable-slot
     activates-on:
     - test-system-activatable-slot
 `, nil)
@@ -379,15 +375,11 @@ slots:
 apps:
   system-service:
     daemon: simple
-    slots:
-    - dbus-session-service-slot
     activates-on:
     - dbus-session-service-slot
   session-service:
     daemon: simple
     daemon-scope: user
-    slots:
-    - dbus-system-service-slot
     activates-on:
     - dbus-system-service-slot
 `

snap/info.go

@@ -851,7 +851,7 @@ type AppInfo struct {
 	RefreshMode     string
 	StopMode        StopModeType
 
-	ActivatesOn []string
+	ActivatesOn []*SlotInfo
 
 	Plugs   map[string]*PlugInfo
 	Slots   map[string]*SlotInfo

snap/info_snap_yaml.go

@@ -357,7 +357,6 @@ func setAppsFromSnapYaml(y snapYaml, snap *Info, strk *scopedTracker) error {
 			PostStopCommand: yApp.PostStopCommand,
 			RestartCond:     yApp.RestartCond,
 			RestartDelay:    yApp.RestartDelay,
-			ActivatesOn:     yApp.ActivatesOn,
 			CommonID:        yApp.CommonID,
 			Environment:     yApp.Environment,
 			Completer:       yApp.Completer,
@@ -377,6 +376,9 @@ func setAppsFromSnapYaml(y snapYaml, snap *Info, strk *scopedTracker) error {
 		if len(yApp.Sockets) > 0 {
 			app.Sockets = make(map[string]*SocketInfo, len(yApp.Sockets))
 		}
+		if len(yApp.ActivatesOn) > 0 {
+			app.ActivatesOn = make([]*SlotInfo, 0, len(yApp.ActivatesOn))
+		}
 		// Daemons default to being system daemons
 		if app.Daemon != "" && app.DaemonScope == "" {
 			app.DaemonScope = SystemDaemon
@@ -437,6 +439,17 @@ func setAppsFromSnapYaml(y snapYaml, snap *Info, strk *scopedTracker) error {
 				Timer: yApp.Timer,
 			}
 		}
+		for _, slotName := range yApp.ActivatesOn {
+			slot, ok := snap.Slots[slotName]
+			if !ok {
+				return fmt.Errorf("invalid activates-on value %q on app %q: slot not found", slotName, appName)
+			}
+			app.ActivatesOn = append(app.ActivatesOn, slot)
+			// Implicitly add the slot to the app
+			strk.markSlot(slot)
+			app.Slots[slotName] = slot
+			slot.Apps[appName] = app
+		}
 		// collect all common IDs
 		if app.CommonID != "" {
 			snap.CommonIDs = append(snap.CommonIDs, app.CommonID)

snap/info_snap_yaml_test.go

@@ -1350,6 +1350,64 @@ slots:
 		app1.Name: app1, app2.Name: app2})
 }
 
+func (s *YamlSuite) TestUnmarshalActivatesOn(c *C) {
+	info, err := snap.InfoFromSnapYaml([]byte(`
+name: snap
+slots:
+    test-slot1:
+    test-slot2:
+apps:
+    daemon:
+        activates-on: ["test-slot1", "test-slot2"]
+    foo:
+`))
+	c.Assert(err, IsNil)
+	c.Check(info.InstanceName(), Equals, "snap")
+	c.Check(info.Plugs, HasLen, 0)
+	c.Check(info.Slots, HasLen, 2)
+	c.Check(info.Apps, HasLen, 2)
+	c.Check(info.Hooks, HasLen, 0)
+
+	app1 := info.Apps["daemon"]
+	app2 := info.Apps["foo"]
+	slot1 := info.Slots["test-slot1"]
+	slot2 := info.Slots["test-slot2"]
+
+	c.Assert(app1, Not(IsNil))
+	c.Check(app1.Name, Equals, "daemon")
+	c.Check(app1.ActivatesOn, DeepEquals, []*snap.SlotInfo{slot1, slot2})
+	// activates-on slots are implicitly added to the app
+	c.Check(app1.Slots, DeepEquals, map[string]*snap.SlotInfo{
+		slot1.Name: slot1, slot2.Name: slot2})
+
+	c.Assert(app2, Not(IsNil))
+	c.Check(app2.Name, Equals, "foo")
+	c.Check(app2.ActivatesOn, HasLen, 0)
+	// As slot has been bound to app1, it isn't implicitly applied here
+	c.Check(app2.Slots, HasLen, 0)
+
+	c.Assert(slot1, Not(IsNil))
+	c.Check(slot1.Name, Equals, "test-slot1")
+	c.Check(slot1.Apps, DeepEquals, map[string]*snap.AppInfo{
+		app1.Name: app1})
+
+	c.Assert(slot2, Not(IsNil))
+	c.Check(slot2.Name, Equals, "test-slot2")
+	c.Check(slot2.Apps, DeepEquals, map[string]*snap.AppInfo{
+		app1.Name: app1})
+}
+
+func (s *YamlSuite) TestUnmarshalActivatesOnUnknownSlot(c *C) {
+	info, err := snap.InfoFromSnapYaml([]byte(`
+name: snap
+apps:
+    daemon:
+        activates-on: ["test-slot"]
+`))
+	c.Check(info, IsNil)
+	c.Check(err, ErrorMatches, `invalid activates-on value "test-slot" on app "daemon": slot not found`)
+}
+
 // type and architectures
 
 func (s *YamlSuite) TestSnapYamlTypeDefault(c *C) {
@@ -1463,9 +1521,6 @@ apps:
    stop-command: stop-cmd
    post-stop-command: post-stop-cmd
    restart-condition: on-abnormal
-   activates-on:
-   - slot1
-   - slot2
    bus-name: busName
    sockets:
      sock1:
@@ -1486,7 +1541,6 @@ apps:
 		StartTimeout:    timeout.Timeout(42 * time.Minute),
 		StopCommand:     "stop-cmd",
 		PostStopCommand: "post-stop-cmd",
-		ActivatesOn:     []string{"slot1", "slot2"},
 		Sockets:         map[string]*snap.SocketInfo{},
 	}
 

snap/validate.go

@@ -666,11 +666,9 @@ func ValidateApp(app *AppInfo) error {
 	}
 
 	// ActivatesOn is a list of slot names that use the "dbus" type
-	for _, slotName := range app.ActivatesOn {
-		if slot, ok := app.Slots[slotName]; !ok {
-			return fmt.Errorf("invalid activates-on value %q: slot not found", slotName)
-		} else if slot.Interface != "dbus" {
-			return fmt.Errorf("invalid activates-on value %q: slot does not use dbus interface", slotName)
+	for _, slot := range app.ActivatesOn {
+		if slot.Interface != "dbus" {
+			return fmt.Errorf("invalid activates-on value %q: slot does not use dbus interface", slot.Name)
 		}
 	}
 

snap/validate_test.go

@@ -580,23 +580,6 @@ apps:
 	c.Check(ValidateApp(app), IsNil)
 }
 
-func (s *ValidateSuite) TestAppActivatesOnSlotNotFound(c *C) {
-	info, err := InfoFromSnapYaml([]byte(`name: foo
-version: 1.0
-slots:
-  dbus-slot:
-    interface: dbus
-apps:
-  server:
-    activates-on: [dbus-slot]
-  other-server:
-    slots: [dbus-slot]
-`))
-	c.Assert(err, IsNil)
-	app := info.Apps["server"]
-	c.Check(ValidateApp(app), ErrorMatches, `invalid activates-on value "dbus-slot": slot not found`)
-}
-
 func (s *ValidateSuite) TestAppActivatesOnSlotNotDbus(c *C) {
 	info, err := InfoFromSnapYaml([]byte(`name: foo
 version: 1.0

wrappers/services.go

@@ -721,7 +721,7 @@ WantedBy={{.ServicesTarget}}
 
 	var busName string
 	if appInfo.Daemon == "dbus" && len(appInfo.ActivatesOn) > 0 {
-		slot := appInfo.Slots[appInfo.ActivatesOn[len(appInfo.ActivatesOn)-1]]
+		slot := appInfo.ActivatesOn[len(appInfo.ActivatesOn)-1]
 		if err := slot.Attr("name", &busName); err != nil {
 			logger.Noticef("Cannot get 'name' attribute of dbus slot %q: %v", slot.Name, err)
 		}