Use spf13/cobra for docker top

This fix is part of the effort to convert commands to spf13/cobra #23211.

Thif fix coverted command `docker top` to use spf13/cobra

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Upstream-commit: 0f3866926763447c247bb24268923b5e50c006e1
Component: engine

components/engine/api/client/container/top.go

@@ -0,0 +1,59 @@
+package container
+
+import (
+	"fmt"
+	"strings"
+	"text/tabwriter"
+
+	"golang.org/x/net/context"
+
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/spf13/cobra"
+)
+
+type topOptions struct {
+	container string
+
+	args []string
+}
+
+// NewTopCommand creats a new cobra.Command for `docker top`
+func NewTopCommand(dockerCli *client.DockerCli) *cobra.Command {
+	var opts topOptions
+
+	cmd := &cobra.Command{
+		Use:   "top CONTAINER [ps OPTIONS]",
+		Short: "Display the running processes of a container",
+		Args:  cli.RequiresMinArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			opts.container = args[0]
+			opts.args = args[1:]
+			return runTop(dockerCli, &opts)
+		},
+	}
+	cmd.SetFlagErrorFunc(flagErrorFunc)
+
+	flags := cmd.Flags()
+	flags.SetInterspersed(false)
+
+	return cmd
+}
+
+func runTop(dockerCli *client.DockerCli, opts *topOptions) error {
+	ctx := context.Background()
+
+	procList, err := dockerCli.Client().ContainerTop(ctx, opts.container, opts.args)
+	if err != nil {
+		return err
+	}
+
+	w := tabwriter.NewWriter(dockerCli.Out(), 20, 1, 3, ' ', 0)
+	fmt.Fprintln(w, strings.Join(procList.Titles, "\t"))
+
+	for _, proc := range procList.Processes {
+		fmt.Fprintln(w, strings.Join(proc, "\t"))
+	}
+	w.Flush()
+	return nil
+}