Fix daemon command proxy.

Signed-off-by: Daniel Nephin <dnephin@docker.com>

cmd/docker/daemon_none_test.go

@@ -3,18 +3,15 @@
 package main
 
 import (
-	"strings"
 	"testing"
+
+	"github.com/docker/docker/pkg/testutil/assert"
 )
 
-func TestCmdDaemon(t *testing.T) {
-	proxy := NewDaemonProxy()
-	err := proxy.CmdDaemon("--help")
-	if err == nil {
-		t.Fatal("Expected CmdDaemon to fail on Windows.")
-	}
+func TestDaemonCommand(t *testing.T) {
+	cmd := newDaemonCommand()
+	cmd.SetArgs([]string{"--help"})
+	err := cmd.Execute()
 
-	if !strings.Contains(err.Error(), "Please run `dockerd`") {
-		t.Fatalf("Expected an error about running dockerd, got %s", err)
-	}
+	assert.Error(t, err, "Please run `dockerd`")
 }

cmd/docker/daemon_unit_test.go

@@ -0,0 +1,30 @@
+// +build daemon
+
+package main
+
+import (
+	"testing"
+
+	"github.com/docker/docker/pkg/testutil/assert"
+	"github.com/spf13/cobra"
+)
+
+func stubRun(cmd *cobra.Command, args []string) error {
+	return nil
+}
+
+func TestDaemonCommandHelp(t *testing.T) {
+	cmd := newDaemonCommand()
+	cmd.RunE = stubRun
+	cmd.SetArgs([]string{"--help"})
+	err := cmd.Execute()
+	assert.NilError(t, err)
+}
+
+func TestDaemonCommand(t *testing.T) {
+	cmd := newDaemonCommand()
+	cmd.RunE = stubRun
+	cmd.SetArgs([]string{"--containerd", "/foo"})
+	err := cmd.Execute()
+	assert.NilError(t, err)
+}

cmd/docker/daemon_unix.go

@@ -19,6 +19,8 @@ func newDaemonCommand() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:                "daemon",
 		Hidden:             true,
+		Args:               cobra.ArbitraryArgs,
+		DisableFlagParsing: true,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			return runDaemon()
 		},