feat: add client-id subcommand to yggctl

This patch adds a 'client-id' subcommand
to yggctl which retrieves and prints to stdout
the active client ID of a yggd instance.

This attempts to resolve issue #243

Signed-off-by: Jason Jerome <[email protected]>

cmd/yggctl/actions.go

@@ -173,6 +173,32 @@ func messageJournalAction(ctx *cli.Context) error {
 	return nil
 }
 
+// clientIDAction connects to the Yggdrasil1 dbus interface
+// and attempts to retrieve the active yggd client id
+// and display the client id to stdout.
+func clientIDAction(ctx *cli.Context) error {
+	conn, err := connectBus()
+	if err != nil {
+		return cli.Exit(fmt.Errorf("cannot connect to bus: %w", err), 1)
+	}
+
+	obj := conn.Object("com.redhat.Yggdrasil1", "/com/redhat/Yggdrasil1")
+	propertyName := "com.redhat.Yggdrasil1.ClientID"
+	result, err := obj.GetProperty(propertyName)
+	if err != nil {
+		return fmt.Errorf(
+			"cannot get property 'com.redhat.Yggdrasil1.ClientID': %v", err)
+	}
+	clientID, ok := result.Value().(map[string]string)
+	if !ok {
+		return cli.Exit(fmt.Errorf("cannot convert %T to map[string]string", result.Value()), 1)
+	}
+
+	fmt.Println(clientID)
+
+	return nil
+}
+
 func workersAction(c *cli.Context) error {
 	conn, err := connectBus()
 	if err != nil {

cmd/yggctl/main.go

@@ -30,6 +30,16 @@ func main() {
 	}
 
 	app.Commands = []*cli.Command{
+		{
+
+			Name:        "client-id",
+			Usage:       "Retrieve the current client id",
+			UsageText:   "yggctl client-id",
+			Description: `The client-id command retrieves the current client id of the yggdrasil instance`,
+			Aliases:     []string{},
+			Flags:       []cli.Flag{},
+			Action:      clientIDAction,
+		},
 		{
 			Name:   "generate",
 			Usage:  `Generate messages for publishing to client "in" topics`,

cmd/yggd/client.go

@@ -201,6 +201,10 @@ func (c *Client) ListWorkers() (map[string]map[string]string, *dbus.Error) {
 	return c.dispatcher.FlattenDispatchers(), nil
 }
 
+func (c *Client) GetClientID() (string, *dbus.Error) {
+	return config.DefaultConfig.ClientID, nil
+}
+
 // MessageJournal implements the com.redhat.Yggdrasil1.MessageJournal method.
 func (c *Client) MessageJournal(
 	messageID string,

data/dbus/yggd.conf.in

@@ -13,6 +13,10 @@
     <!-- Only members of the @worker_user@ group can send messages to
     Dispatcher1 destination. -->
     <allow send_destination="com.redhat.Yggdrasil1.Dispatcher1" />
+
+    <!-- Only @worker_user@ can send messages to the Properties interface. -->
+    <allow send_destination="com.redhat.Yggdrasil1"
+        send_interface="org.freedesktop.DBus.Properties" />
   </policy>
 
   <policy context="default">

dbus/com.redhat.Yggdrasil1.xml

@@ -8,6 +8,13 @@
         programmatic interaction with the yggdrasil system service.
     -->
     <interface name="com.redhat.Yggdrasil1">
+        <!--
+            ClientID:
+            
+            The value of the current client id on the active interface.
+        -->
+        <property name="ClientID" type="s" access="read" />
+
         <!-- 
             Dispatch:
             @directive: worker identifier for which the data is destined.