commands: add prune command

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

commands/prune.go

@@ -0,0 +1,196 @@
+package commands
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"text/tabwriter"
+	"time"
+
+	"github.com/docker/buildx/build"
+	"github.com/docker/cli/cli"
+	"github.com/docker/cli/cli/command"
+	"github.com/docker/cli/opts"
+	"github.com/docker/docker/api/types/filters"
+	"github.com/moby/buildkit/client"
+	"github.com/moby/buildkit/util/appcontext"
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+	"github.com/tonistiigi/units"
+	"golang.org/x/sync/errgroup"
+)
+
+type pruneOptions struct {
+	all         bool
+	filter      opts.FilterOpt
+	keepStorage opts.MemBytes
+	force       bool
+	verbose     bool
+}
+
+const (
+	normalWarning   = `WARNING! This will remove all dangling build cache. Are you sure you want to continue?`
+	allCacheWarning = `WARNING! This will remove all build cache. Are you sure you want to continue?`
+)
+
+func runPrune(dockerCli command.Cli, opts pruneOptions) error {
+	ctx := appcontext.Context()
+
+	pruneFilters := opts.filter.Value()
+	pruneFilters = command.PruneFilters(dockerCli, pruneFilters)
+
+	pi, err := toBuildkitPruneInfo(pruneFilters)
+	if err != nil {
+		return err
+	}
+
+	warning := normalWarning
+	if opts.all {
+		warning = allCacheWarning
+	}
+
+	if !opts.force && !command.PromptForConfirmation(dockerCli.In(), dockerCli.Out(), warning) {
+		return nil
+	}
+
+	dis, err := getDefaultDrivers(ctx, dockerCli, "")
+	if err != nil {
+		return err
+	}
+
+	for _, di := range dis {
+		if di.Err != nil {
+			return err
+		}
+	}
+
+	ch := make(chan client.UsageInfo)
+	printed := make(chan struct{})
+
+	tw := tabwriter.NewWriter(os.Stdout, 1, 8, 1, '\t', 0)
+	first := true
+	total := int64(0)
+
+	go func() {
+		defer close(printed)
+		for du := range ch {
+			total += du.Size
+			if opts.verbose {
+				printVerbose(tw, []*client.UsageInfo{&du})
+			} else {
+				if first {
+					printTableHeader(tw)
+					first = false
+				}
+				printTableRow(tw, &du)
+				tw.Flush()
+			}
+		}
+	}()
+
+	eg, ctx := errgroup.WithContext(ctx)
+	for _, di := range dis {
+		func(di build.DriverInfo) {
+			eg.Go(func() error {
+				if di.Driver != nil {
+					c, err := di.Driver.Client(ctx)
+					if err != nil {
+						return err
+					}
+					popts := []client.PruneOption{
+						client.WithKeepOpt(pi.KeepDuration, opts.keepStorage.Value()),
+						client.WithFilter(pi.Filter),
+					}
+					if opts.all {
+						popts = append(popts, client.PruneAll)
+					}
+					return c.Prune(ctx, ch, popts...)
+				}
+				return nil
+			})
+		}(di)
+	}
+
+	if err := eg.Wait(); err != nil {
+		return err
+	}
+	close(ch)
+	<-printed
+
+	tw = tabwriter.NewWriter(os.Stdout, 1, 8, 1, '\t', 0)
+	fmt.Fprintf(tw, "Total:\t%.2f\n", units.Bytes(total))
+	tw.Flush()
+	return nil
+}
+
+func pruneCmd(dockerCli command.Cli) *cobra.Command {
+	options := pruneOptions{filter: opts.NewFilterOpt()}
+
+	cmd := &cobra.Command{
+		Use:   "prune",
+		Short: "Remove build cache ",
+		Args:  cli.NoArgs,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runPrune(dockerCli, options)
+		},
+		Annotations: map[string]string{"version": "1.00"},
+	}
+
+	flags := cmd.Flags()
+	flags.BoolVarP(&options.all, "all", "a", false, "Remove all unused images, not just dangling ones")
+	flags.Var(&options.filter, "filter", "Provide filter values (e.g. 'until=24h')")
+	flags.Var(&options.keepStorage, "keep-storage", "Amount of disk space to keep for cache")
+	flags.BoolVar(&options.verbose, "verbose", false, "Provide a more verbose output")
+	flags.BoolVar(&options.force, "force", false, "Skip the warning messages")
+
+	return cmd
+}
+
+func toBuildkitPruneInfo(f filters.Args) (*client.PruneInfo, error) {
+	var until time.Duration
+	untilValues := f.Get("until")          // canonical
+	unusedForValues := f.Get("unused-for") // deprecated synonym for "until" filter
+
+	if len(untilValues) > 0 && len(unusedForValues) > 0 {
+		return nil, errors.Errorf("conflicting filters %q and %q", "until", "unused-for")
+	}
+	filterKey := "until"
+	if len(unusedForValues) > 0 {
+		filterKey = "unused-for"
+	}
+	untilValues = append(untilValues, unusedForValues...)
+
+	switch len(untilValues) {
+	case 0:
+		// nothing to do
+	case 1:
+		var err error
+		until, err = time.ParseDuration(untilValues[0])
+		if err != nil {
+			return nil, errors.Wrapf(err, "%q filter expects a duration (e.g., '24h')", filterKey)
+		}
+	default:
+		return nil, errors.Errorf("filters expect only one value")
+	}
+
+	bkFilter := make([]string, 0, f.Len())
+	for _, field := range f.Keys() {
+		values := f.Get(field)
+		switch len(values) {
+		case 0:
+			bkFilter = append(bkFilter, field)
+		case 1:
+			if field == "id" {
+				bkFilter = append(bkFilter, field+"~="+values[0])
+			} else {
+				bkFilter = append(bkFilter, field+"=="+values[0])
+			}
+		default:
+			return nil, errors.Errorf("filters expect only one value")
+		}
+	}
+	return &client.PruneInfo{
+		KeepDuration: until,
+		Filter:       []string{strings.Join(bkFilter, ",")},
+	}, nil
+}