login1: Add RebootWithContext method

Existing Reboot() method does not allow using context not inspecting
D-Bus call errors, which makes it difficult to debug and use.

This commit adds new RebootWithContext() method which addresses those
shortcomings.

Closes #387

Signed-off-by: Mateusz Gozdek <[email protected]>

Author: invidian

login1/dbus.go

@@ -16,6 +16,7 @@
 package login1
 
 import (
+	"context"
 	"fmt"
 	"os"
 	"strconv"
@@ -59,6 +60,7 @@ type connectionManager interface {
 type Caller interface {
 	// TODO: This method should eventually be removed, as it provides no context support.
 	Call(method string, flags dbus.Flags, args ...interface{}) *dbus.Call
+	CallWithContext(ctx context.Context, method string, flags dbus.Flags, args ...interface{}) *dbus.Call
 }
 
 // New establishes a connection to the system bus and authenticates.
@@ -347,6 +349,15 @@ func (c *Conn) Reboot(askForAuth bool) {
 	c.object.Call(dbusInterface+".Reboot", 0, askForAuth)
 }
 
+// Reboot asks logind for a reboot using given context, optionally asking for auth.
+func (c *Conn) RebootWithContext(ctx context.Context, askForAuth bool) error {
+	if call := c.object.CallWithContext(ctx, dbusInterface+".Reboot", 0, askForAuth); call.Err != nil {
+		return fmt.Errorf("calling reboot: %w", call.Err)
+	}
+
+	return nil
+}
+
 // Inhibit takes inhibition lock in logind.
 func (c *Conn) Inhibit(what, who, why, mode string) (*os.File, error) {
 	var fd dbus.UnixFD

login1/dbus_test.go

@@ -15,6 +15,8 @@
 package login1_test
 
 import (
+	"context"
+	"errors"
 	"fmt"
 	"os/user"
 	"regexp"
@@ -142,6 +144,168 @@ func Test_Creating_new_connection_with_custom_connection(t *testing.T) {
 	})
 }
 
+//nolint:funlen // Many subtests.
+func Test_Rebooting_with_context(t *testing.T) {
+	t.Parallel()
+
+	t.Run("calls_login1_reboot_method_on_manager_interface", func(t *testing.T) {
+		t.Parallel()
+
+		rebootCalled := false
+
+		askForReboot := false
+
+		connectionWithContextCheck := &mockConnection{
+			ObjectF: func(string, dbus.ObjectPath) dbus.BusObject {
+				return &mockObject{
+					CallWithContextF: func(ctx context.Context, method string, flags dbus.Flags, args ...interface{}) *dbus.Call {
+						rebootCalled = true
+
+						expectedMethodName := "org.freedesktop.login1.Manager.Reboot"
+
+						if method != expectedMethodName {
+							t.Fatalf("Expected method %q being called, got %q", expectedMethodName, method)
+						}
+
+						if len(args) != 1 {
+							t.Fatalf("Expected one argument to call, got %q", args)
+						}
+
+						askedForReboot, ok := args[0].(bool)
+						if !ok {
+							t.Fatalf("Expected first argument to be of type %T, got %T", askForReboot, args[0])
+						}
+
+						if askForReboot != askedForReboot {
+							t.Fatalf("Expected argument to be %t, got %t", askForReboot, askedForReboot)
+						}
+
+						return &dbus.Call{}
+					},
+				}
+			},
+		}
+
+		testConn, err := login1.NewWithConnection(connectionWithContextCheck)
+		if err != nil {
+			t.Fatalf("Unexpected error creating connection: %v", err)
+		}
+
+		if err := testConn.RebootWithContext(context.Background(), askForReboot); err != nil {
+			t.Fatalf("Unexpected error rebooting: %v", err)
+		}
+
+		if !rebootCalled {
+			t.Fatalf("Expected reboot method call on given D-Bus connection")
+		}
+	})
+
+	t.Run("asks_for_auth_when_requested", func(t *testing.T) {
+		t.Parallel()
+
+		rebootCalled := false
+
+		askForReboot := true
+
+		connectionWithContextCheck := &mockConnection{
+			ObjectF: func(string, dbus.ObjectPath) dbus.BusObject {
+				return &mockObject{
+					CallWithContextF: func(ctx context.Context, method string, flags dbus.Flags, args ...interface{}) *dbus.Call {
+						rebootCalled = true
+
+						if len(args) != 1 {
+							t.Fatalf("Expected one argument to call, got %q", args)
+						}
+
+						askedForReboot, ok := args[0].(bool)
+						if !ok {
+							t.Fatalf("Expected first argument to be of type %T, got %T", askForReboot, args[0])
+						}
+
+						if askForReboot != askedForReboot {
+							t.Fatalf("Expected argument to be %t, got %t", askForReboot, askedForReboot)
+						}
+
+						return &dbus.Call{}
+					},
+				}
+			},
+		}
+
+		testConn, err := login1.NewWithConnection(connectionWithContextCheck)
+		if err != nil {
+			t.Fatalf("Unexpected error creating connection: %v", err)
+		}
+
+		if err := testConn.RebootWithContext(context.Background(), askForReboot); err != nil {
+			t.Fatalf("Unexpected error rebooting: %v", err)
+		}
+
+		if !rebootCalled {
+			t.Fatalf("Expected reboot method call on given D-Bus connection")
+		}
+	})
+
+	t.Run("use_given_context_for_D-Bus_call", func(t *testing.T) {
+		t.Parallel()
+
+		testKey := struct{}{}
+		expectedValue := "bar"
+
+		ctx := context.WithValue(context.Background(), testKey, expectedValue)
+
+		connectionWithContextCheck := &mockConnection{
+			ObjectF: func(string, dbus.ObjectPath) dbus.BusObject {
+				return &mockObject{
+					CallWithContextF: func(ctx context.Context, method string, flags dbus.Flags, args ...interface{}) *dbus.Call {
+						if val := ctx.Value(testKey); val != expectedValue {
+							t.Fatalf("Got unexpected context on call")
+						}
+
+						return &dbus.Call{}
+					},
+				}
+			},
+		}
+
+		testConn, err := login1.NewWithConnection(connectionWithContextCheck)
+		if err != nil {
+			t.Fatalf("Unexpected error creating connection: %v", err)
+		}
+
+		if err := testConn.RebootWithContext(ctx, false); err != nil {
+			t.Fatalf("Unexpected error rebooting: %v", err)
+		}
+	})
+
+	t.Run("returns_error_when_D-Bus_call_fails", func(t *testing.T) {
+		t.Parallel()
+
+		expectedError := fmt.Errorf("reboot error")
+
+		connectionWithFailingObjectCall := &mockConnection{
+			ObjectF: func(string, dbus.ObjectPath) dbus.BusObject {
+				return &mockObject{
+					CallWithContextF: func(ctx context.Context, method string, flags dbus.Flags, args ...interface{}) *dbus.Call {
+						return &dbus.Call{
+							Err: expectedError,
+						}
+					},
+				}
+			},
+		}
+
+		testConn, err := login1.NewWithConnection(connectionWithFailingObjectCall)
+		if err != nil {
+			t.Fatalf("Unexpected error creating connection: %v", err)
+		}
+
+		if err := testConn.RebootWithContext(context.Background(), false); !errors.Is(err, expectedError) {
+			t.Fatalf("Unexpected error rebooting: %v", err)
+		}
+	})
+}
+
 // mockConnection is a test helper for mocking dbus.Conn.
 type mockConnection struct {
 	ObjectF func(string, dbus.ObjectPath) dbus.BusObject
@@ -178,3 +342,70 @@ func (m *mockConnection) Close() error {
 func (m *mockConnection) BusObject() dbus.BusObject {
 	return nil
 }
+
+// mockObject is a mock of dbus.BusObject.
+type mockObject struct {
+	CallWithContextF func(context.Context, string, dbus.Flags, ...interface{}) *dbus.Call
+	CallF            func(string, dbus.Flags, ...interface{}) *dbus.Call
+}
+
+// mockObject must implement dbus.BusObject to be usable for other packages in tests, though not
+// all methods must actually be mockable. See https://github.com/dbus/dbus/issues/252 for details.
+var _ dbus.BusObject = &mockObject{}
+
+// CallWithContext ...
+//
+//nolint:lll // Upstream signature, can't do much with that.
+func (m *mockObject) CallWithContext(ctx context.Context, method string, flags dbus.Flags, args ...interface{}) *dbus.Call {
+	if m.CallWithContextF == nil {
+		return &dbus.Call{}
+	}
+
+	return m.CallWithContextF(ctx, method, flags, args...)
+}
+
+// Call ...
+func (m *mockObject) Call(method string, flags dbus.Flags, args ...interface{}) *dbus.Call {
+	if m.CallF == nil {
+		return &dbus.Call{}
+	}
+
+	return m.CallF(method, flags, args...)
+}
+
+// Go ...
+func (m *mockObject) Go(method string, flags dbus.Flags, ch chan *dbus.Call, args ...interface{}) *dbus.Call {
+	return &dbus.Call{}
+}
+
+// GoWithContext ...
+//
+//nolint:lll // Upstream signature, can't do much with that.
+func (m *mockObject) GoWithContext(ctx context.Context, method string, flags dbus.Flags, ch chan *dbus.Call, args ...interface{}) *dbus.Call {
+	return &dbus.Call{}
+}
+
+// AddMatchSignal ...
+func (m *mockObject) AddMatchSignal(iface, member string, options ...dbus.MatchOption) *dbus.Call {
+	return &dbus.Call{}
+}
+
+// RemoveMatchSignal ...
+func (m *mockObject) RemoveMatchSignal(iface, member string, options ...dbus.MatchOption) *dbus.Call {
+	return &dbus.Call{}
+}
+
+// GetProperty ...
+func (m *mockObject) GetProperty(p string) (dbus.Variant, error) { return dbus.Variant{}, nil }
+
+// StoreProperty ...
+func (m *mockObject) StoreProperty(p string, value interface{}) error { return nil }
+
+// SetProperty ...
+func (m *mockObject) SetProperty(p string, v interface{}) error { return nil }
+
+// Destination ...
+func (m *mockObject) Destination() string { return "" }
+
+// Path ...
+func (m *mockObject) Path() dbus.ObjectPath { return "" }