Merge pull request #31482 from ripcurld0/add_format_to_system_df

Add format to the docker system df command

command/system/df.go

@@ -1,6 +1,8 @@
 package system
 
 import (
+	"errors"
+
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
 	"github.com/docker/docker/cli/command/formatter"
@@ -10,6 +12,7 @@ import (
 
 type diskUsageOptions struct {
 	verbose bool
+	format  string
 }
 
 // NewDiskUsageCommand creates a new cobra.Command for `docker df`
@@ -29,19 +32,30 @@ func NewDiskUsageCommand(dockerCli *command.DockerCli) *cobra.Command {
 	flags := cmd.Flags()
 
 	flags.BoolVarP(&opts.verbose, "verbose", "v", false, "Show detailed information on space usage")
+	flags.StringVar(&opts.format, "format", "", "Pretty-print images using a Go template")
 
 	return cmd
 }
 
 func runDiskUsage(dockerCli *command.DockerCli, opts diskUsageOptions) error {
+	if opts.verbose && len(opts.format) != 0 {
+		return errors.New("the verbose and the format options conflict")
+	}
+
 	du, err := dockerCli.Client().DiskUsage(context.Background())
 	if err != nil {
 		return err
 	}
 
+	format := opts.format
+	if len(format) == 0 {
+		format = formatter.TableFormatKey
+	}
+
 	duCtx := formatter.DiskUsageContext{
 		Context: formatter.Context{
 			Output: dockerCli.Out(),
+			Format: formatter.NewDiskUsageFormat(format),
 		},
 		LayersSize: du.LayersSize,
 		Images:     du.Images,
@@ -50,7 +64,5 @@ func runDiskUsage(dockerCli *command.DockerCli, opts diskUsageOptions) error {
 		Verbose:    opts.verbose,
 	}
 
-	duCtx.Write()
-
-	return nil
+	return duCtx.Write()
 }