login1: add NewWithConnection and RebootWithContext methods

.github/workflows/go.yml

@@ -11,7 +11,7 @@ permissions:
 
 env:
   # Minimum supported Go toolchain
-  ACTION_MINIMUM_TOOLCHAIN: "1.12"
+  ACTION_MINIMUM_TOOLCHAIN: "1.13"
 
 jobs:
   build:

README.md

@@ -1,7 +1,7 @@
 # go-systemd
 
 [![godoc](https://img.shields.io/badge/godoc-reference-5272B4)](https://pkg.go.dev/mod/github.com/coreos/go-systemd/v22/?tab=packages)
-![minimum golang 1.12](https://img.shields.io/badge/golang-1.12%2B-orange.svg)
+![minimum golang 1.13](https://img.shields.io/badge/golang-1.13%2B-orange.svg)
 
 
 Go bindings to systemd. The project has several packages:

go.mod

@@ -1,5 +1,5 @@
 module github.com/coreos/go-systemd/v22
 
-go 1.12
+go 1.13
 
 require github.com/godbus/dbus/v5 v5.0.4

login1/dbus.go

@@ -16,6 +16,7 @@
 package login1
 
 import (
+	"context"
 	"fmt"
 	"os"
 	"strconv"
@@ -32,8 +33,34 @@ const (
 
 // Conn is a connection to systemds dbus endpoint.
 type Conn struct {
-	conn   *dbus.Conn
-	object dbus.BusObject
+	conn        Connection
+	connManager connectionManager
+	object      Caller
+}
+
+// Objector describes functionality required from a given D-Bus connection.
+type Connection interface {
+	Object(string, dbus.ObjectPath) dbus.BusObject
+	Signal(ch chan<- *dbus.Signal)
+	// TODO: This should be replaced with AddMatchSignal.
+	// See https://github.com/coreos/go-systemd/issues/388 for details.
+	BusObject() dbus.BusObject
+}
+
+// ConnectionManager explicitly wraps dependencies on established D-Bus connection.
+type connectionManager interface {
+	Hello() error
+	Auth(authMethods []dbus.Auth) error
+	Close() error
+
+	Connection
+}
+
+// Caller describes required functionality from D-Bus object.
+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.
@@ -47,20 +74,32 @@ func New() (*Conn, error) {
 	return c, nil
 }
 
+// NewWithConnection creates new login1 client using given D-Bus connection.
+func NewWithConnection(connection Connection) (*Conn, error) {
+	if connection == nil {
+		return nil, fmt.Errorf("no connection given")
+	}
+
+	return &Conn{
+		conn:   connection,
+		object: connection.Object(dbusDest, dbusPath),
+	}, nil
+}
+
 // Close closes the dbus connection
 func (c *Conn) Close() {
 	if c == nil {
 		return
 	}
 
-	if c.conn != nil {
-		c.conn.Close()
+	if c.conn != nil && c.connManager != nil {
+		c.connManager.Close()
 	}
 }
 
 func (c *Conn) initConnection() error {
 	var err error
-	c.conn, err = dbus.SystemBusPrivate()
+	c.connManager, err = dbus.SystemBusPrivate()
 	if err != nil {
 		return err
 	}
@@ -70,18 +109,19 @@ func (c *Conn) initConnection() error {
 	// libc)
 	methods := []dbus.Auth{dbus.AuthExternal(strconv.Itoa(os.Getuid()))}
 
-	err = c.conn.Auth(methods)
+	err = c.connManager.Auth(methods)
 	if err != nil {
-		c.conn.Close()
+		c.connManager.Close()
 		return err
 	}
 
-	err = c.conn.Hello()
+	err = c.connManager.Hello()
 	if err != nil {
-		c.conn.Close()
+		c.connManager.Close()
 		return err
 	}
 
+	c.conn = c.connManager
 	c.object = c.conn.Object("org.freedesktop.login1", dbus.ObjectPath(dbusPath))
 
 	return nil
@@ -309,6 +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