cmd: pluginMain: use WithUserAgent option

Rewrite the custom user agent to use the new options that were added
in the cli:

- plugin.Run now accepts custom CLI options to allow customizing the CLI's
- cli/command now has a WithUserAgent option to customize the CLI's user-
  agent, allowing it to be overridden from the default.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cmd/main.go

@@ -24,7 +24,6 @@ import (
 	"github.com/docker/cli/cli-plugins/plugin"
 	"github.com/docker/cli/cli/command"
 	"github.com/docker/compose/v2/cmd/cmdtrace"
-	"github.com/docker/docker/client"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 
@@ -35,7 +34,8 @@ import (
 )
 
 func pluginMain() {
-	plugin.Run(func(dockerCli command.Cli) *cobra.Command {
+	plugin.Run(
+		func(dockerCli command.Cli) *cobra.Command {
 			// TODO(milas): this cast is safe but we should not need to do this,
 			// 	we should expose the concrete service type so that we do not need
 			// 	to rely on the `api.Service` interface internally
@@ -47,16 +47,6 @@ func pluginMain() {
 				if err := plugin.PersistentPreRunE(cmd, args); err != nil {
 					return err
 				}
-			// compose-specific initialization. This must be called AFTER
-			// plugin.PersistentPreRunE.
-			//
-			// FIXME(milas): remove once https://github.com/docker/cli/pull/4574 is merged; for now,
-			//  set it in a rather roundabout way by grabbing the underlying
-			//  concrete client and manually invoking an option on it
-			if mobyClient, ok := dockerCli.Client().(*client.Client); ok {
-				_ = client.WithUserAgent("compose/" + internal.Version)(mobyClient)
-			}
-
 				if err := cmdtrace.Setup(cmd, dockerCli, os.Args[1:]); err != nil {
 					logrus.Debugf("failed to enable tracing: %v", err)
 				}
@@ -79,7 +69,9 @@ func pluginMain() {
 			SchemaVersion: "0.1.0",
 			Vendor:        "Docker Inc.",
 			Version:       internal.Version,
-		})
+		},
+		command.WithUserAgent("compose/"+internal.Version),
+	)
 }
 
 func main() {