Move api/client -> cli/command

Using
  gomvpkg
     -from github.com/docker/docker/api/client
     -to github.com/docker/docker/cli/command
     -vcs_mv_cmd 'git mv {{.Src}} {{.Dst}}'

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

command/node/cmd.go

@@ -0,0 +1,47 @@
+package node
+
+import (
+	"fmt"
+
+	"github.com/docker/docker/cli"
+	"github.com/docker/docker/cli/command"
+	apiclient "github.com/docker/docker/client"
+	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
+)
+
+// NewNodeCommand returns a cobra command for `node` subcommands
+func NewNodeCommand(dockerCli *command.DockerCli) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "node",
+		Short: "Manage Docker Swarm nodes",
+		Args:  cli.NoArgs,
+		Run: func(cmd *cobra.Command, args []string) {
+			fmt.Fprintf(dockerCli.Err(), "\n"+cmd.UsageString())
+		},
+	}
+	cmd.AddCommand(
+		newDemoteCommand(dockerCli),
+		newInspectCommand(dockerCli),
+		newListCommand(dockerCli),
+		newPromoteCommand(dockerCli),
+		newRemoveCommand(dockerCli),
+		newPsCommand(dockerCli),
+		newUpdateCommand(dockerCli),
+	)
+	return cmd
+}
+
+// Reference returns the reference of a node. The special value "self" for a node
+// reference is mapped to the current node, hence the node ID is retrieved using
+// the `/info` endpoint.
+func Reference(ctx context.Context, client apiclient.APIClient, ref string) (string, error) {
+	if ref == "self" {
+		info, err := client.Info(ctx)
+		if err != nil {
+			return "", err
+		}
+		return info.Swarm.NodeID, nil
+	}
+	return ref, nil
+}