Merge pull request #30962 from TheHipbot/30431-implement-format-for-history-with-docs

30431 implement format for history with docs

command/image/history.go

@@ -1,19 +1,11 @@
 package image
 
 import (
-	"fmt"
-	"strconv"
-	"strings"
-	"text/tabwriter"
-	"time"
-
 	"golang.org/x/net/context"
 
 	"github.com/docker/docker/cli"
 	"github.com/docker/docker/cli/command"
-	"github.com/docker/docker/pkg/stringid"
-	"github.com/docker/docker/pkg/stringutils"
-	"github.com/docker/go-units"
+	"github.com/docker/docker/cli/command/formatter"
 	"github.com/spf13/cobra"
 )
 
@@ -23,6 +15,7 @@ type historyOptions struct {
 	human   bool
 	quiet   bool
 	noTrunc bool
+	format  string
 }
 
 // NewHistoryCommand creates a new `docker history` command
@@ -44,6 +37,7 @@ func NewHistoryCommand(dockerCli *command.DockerCli) *cobra.Command {
 	flags.BoolVarP(&opts.human, "human", "H", true, "Print sizes and dates in human readable format")
 	flags.BoolVarP(&opts.quiet, "quiet", "q", false, "Only show numeric IDs")
 	flags.BoolVar(&opts.noTrunc, "no-trunc", false, "Don't truncate output")
+	flags.StringVar(&opts.format, "format", "", "Pretty-print images using a Go template")
 
 	return cmd
 }
@@ -56,44 +50,15 @@ func runHistory(dockerCli *command.DockerCli, opts historyOptions) error {
 		return err
 	}
 
-	w := tabwriter.NewWriter(dockerCli.Out(), 20, 1, 3, ' ', 0)
-
-	if opts.quiet {
-		for _, entry := range history {
-			if opts.noTrunc {
-				fmt.Fprintf(w, "%s\n", entry.ID)
-			} else {
-				fmt.Fprintf(w, "%s\n", stringid.TruncateID(entry.ID))
-			}
-		}
-		w.Flush()
-		return nil
+	format := opts.format
+	if len(format) == 0 {
+		format = formatter.TableFormatKey
 	}
 
-	var imageID string
-	var createdBy string
-	var created string
-	var size string
-
-	fmt.Fprintln(w, "IMAGE\tCREATED\tCREATED BY\tSIZE\tCOMMENT")
-	for _, entry := range history {
-		imageID = entry.ID
-		createdBy = strings.Replace(entry.CreatedBy, "\t", " ", -1)
-		if !opts.noTrunc {
-			createdBy = stringutils.Ellipsis(createdBy, 45)
-			imageID = stringid.TruncateID(entry.ID)
-		}
-
-		if opts.human {
-			created = units.HumanDuration(time.Now().UTC().Sub(time.Unix(entry.Created, 0))) + " ago"
-			size = units.HumanSizeWithPrecision(float64(entry.Size), 3)
-		} else {
-			created = time.Unix(entry.Created, 0).Format(time.RFC3339)
-			size = strconv.FormatInt(entry.Size, 10)
-		}
-
-		fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s\n", imageID, created, createdBy, size, entry.Comment)
+	historyCtx := formatter.Context{
+		Output: dockerCli.Out(),
+		Format: formatter.NewHistoryFormat(format, opts.quiet, opts.human),
+		Trunc:  !opts.noTrunc,
 	}
-	w.Flush()
-	return nil
+	return formatter.HistoryWrite(historyCtx, opts.human, history)
 }