Add support for service action reload (#443)

* Add support for service action reload

Adds support for reloading a systemd/unknown service via an
`ACTION_RELOAD` service action request.

* Update ReloadRemoteService to support multiple targets

Updates the `ReloadRemoteService` helper function to support multiple
targets in its invocation.

* Remove inaccurate comment on ReloadRemoteService

This function now _does_ support multiple targets.

services/service/client/client.go

@@ -49,6 +49,7 @@ func (*serviceCmd) GetSubpackage(f *flag.FlagSet) *subcommands.Commander {
 	c.Register(&actionCmd{action: pb.Action_ACTION_STOP}, "")
 	c.Register(&actionCmd{action: pb.Action_ACTION_ENABLE}, "")
 	c.Register(&actionCmd{action: pb.Action_ACTION_DISABLE}, "")
+	c.Register(&actionCmd{action: pb.Action_ACTION_RELOAD}, "")
 	return c
 }
 

services/service/client/utils.go

@@ -155,3 +155,17 @@ func DisableRemoteService(ctx context.Context, conn *proxy.Conn, system pb.Syste
 	}
 	return nil
 }
+
+// ReloadRemoteService is a helper function for reloading a service on a remote target
+// using a proxy.Conn.
+func ReloadRemoteService(ctx context.Context, conn *proxy.Conn, system pb.SystemType, service string) error {
+	c := pb.NewServiceClientProxy(conn)
+	if _, err := c.ActionOneMany(ctx, &pb.ActionRequest{
+		ServiceName: service,
+		SystemType:  system,
+		Action:      pb.Action_ACTION_RELOAD,
+	}); err != nil {
+		return fmt.Errorf("can't reload service %s - %v", service, err)
+	}
+	return nil
+}

services/service/server/server_linux.go

@@ -148,6 +148,7 @@ type systemdConnection interface {
 	DisableUnitFilesContext(ctx context.Context, files []string, runtime bool) ([]dbus.DisableUnitFileChange, error)
 	EnableUnitFilesContext(ctx context.Context, files []string, runtime bool, force bool) (bool, []dbus.EnableUnitFileChange, error)
 	ReloadContext(ctx context.Context) error
+	ReloadUnitContext(ctx context.Context, name string, mode string, ch chan<- string) (int, error)
 	Close()
 }
 
@@ -332,6 +333,8 @@ func (s *server) Action(ctx context.Context, req *pb.ActionRequest) (*pb.ActionR
 		_, err = conn.RestartUnitContext(ctx, unitName, modeReplace, resultChan)
 	case pb.Action_ACTION_STOP:
 		_, err = conn.StopUnitContext(ctx, unitName, modeReplace, resultChan)
+	case pb.Action_ACTION_RELOAD:
+		_, err = conn.ReloadUnitContext(ctx, unitName, modeReplace, resultChan)
 	case pb.Action_ACTION_ENABLE:
 		_, _, err = conn.EnableUnitFilesContext(ctx, []string{unitName}, false, true)
 	case pb.Action_ACTION_DISABLE:
@@ -351,7 +354,7 @@ func (s *server) Action(ctx context.Context, req *pb.ActionRequest) (*pb.ActionR
 	// Enable/disable don't use this method so we skip the channel (since it would hang)
 	// and instead force a reload which is what systemctl does when it enables/disables.
 	switch req.Action {
-	case pb.Action_ACTION_START, pb.Action_ACTION_RESTART, pb.Action_ACTION_STOP:
+	case pb.Action_ACTION_START, pb.Action_ACTION_RESTART, pb.Action_ACTION_STOP, pb.Action_ACTION_RELOAD:
 		result := <-resultChan
 		if result != operationResultDone {
 			recorder.CounterOrLog(ctx, serviceActionFailureCounter, 1, attribute.String("reason", "action_err"))

services/service/server/server_linux_test.go

@@ -63,6 +63,9 @@ func (e errConn) EnableUnitFilesContext(context.Context, []string, bool, bool) (
 func (e errConn) ReloadContext(ctx context.Context) error {
 	return errors.New(string(e))
 }
+func (e errConn) ReloadUnitContext(context.Context, string, string, chan<- string) (int, error) {
+	return 0, errors.New(string(e))
+}
 func (errConn) Close() {}
 
 func TestDialError(t *testing.T) {
@@ -124,6 +127,9 @@ func (l listConn) EnableUnitFilesContext(context.Context, []string, bool, bool)
 func (l listConn) ReloadContext(ctx context.Context) error {
 	return notImplementedError
 }
+func (l listConn) ReloadUnitContext(context.Context, string, string, chan<- string) (int, error) {
+	return 0, notImplementedError
+}
 func (listConn) Close() {}
 
 func wantStatusErr(code codes.Code, message string) func(string, error, *testing.T) {
@@ -253,6 +259,9 @@ func (g getConn) EnableUnitFilesContext(context.Context, []string, bool, bool) (
 func (g getConn) ReloadContext(ctx context.Context) error {
 	return notImplementedError
 }
+func (g getConn) ReloadUnitContext(context.Context, string, string, chan<- string) (int, error) {
+	return 0, notImplementedError
+}
 func (getConn) Close() {}
 
 func TestStatus(t *testing.T) {
@@ -518,6 +527,12 @@ func (a actionConn) EnableUnitFilesContext(context.Context, []string, bool, bool
 func (a actionConn) ReloadContext(ctx context.Context) error {
 	return a.reloadErr
 }
+func (a actionConn) ReloadUnitContext(ctx context.Context, name string, mode string, c chan<- string) (int, error) {
+	go func() {
+		c <- string(a.action)
+	}()
+	return 1, a.err
+}
 func (actionConn) Close() {}
 
 func TestAction(t *testing.T) {
@@ -635,6 +650,16 @@ func TestAction(t *testing.T) {
 			want:    nil,
 			errFunc: wantStatusErr(codes.Internal, "error reloading"),
 		},
+		{
+			name: "reload failed",
+			conn: actionConn{"failed", nil, nil},
+			req: &pb.ActionRequest{
+				ServiceName: "foo",
+				Action:      pb.Action_ACTION_RELOAD,
+			},
+			want:    nil,
+			errFunc: wantStatusErr(codes.Internal, "error performing action"),
+		},
 		{
 			name: "start success",
 			conn: actionConn{operationResultDone, nil, nil},
@@ -700,6 +725,19 @@ func TestAction(t *testing.T) {
 			},
 			errFunc: testutil.FatalOnErr,
 		},
+		{
+			name: "reload success",
+			conn: actionConn{operationResultDone, nil, nil},
+			req: &pb.ActionRequest{
+				ServiceName: "foo",
+				Action:      pb.Action_ACTION_RELOAD,
+			},
+			want: &pb.ActionReply{
+				SystemType:  pb.SystemType_SYSTEM_TYPE_SYSTEMD,
+				ServiceName: "foo",
+			},
+			errFunc: testutil.FatalOnErr,
+		},
 	} {
 		tc := tc
 		t.Run(tc.name, func(t *testing.T) {

services/service/service.proto

@@ -56,6 +56,7 @@ enum Action {
   ACTION_RESTART = 3;
   ACTION_ENABLE = 4;
   ACTION_DISABLE = 5;
+  ACTION_RELOAD = 6;
 }
 
 // ServiceStatus pairs a service with it's current status.