buildctl (du|prune|debug info): support --format {{json .}}

client/diskusage.go

@@ -10,18 +10,18 @@ import (
 )
 
 type UsageInfo struct {
-	ID      string
-	Mutable bool
-	InUse   bool
-	Size    int64
+	ID      string `json:"id"`
+	Mutable bool   `json:"mutable"`
+	InUse   bool   `json:"inUse"`
+	Size    int64  `json:"size"`
 
-	CreatedAt   time.Time
-	LastUsedAt  *time.Time
-	UsageCount  int
-	Parents     []string
-	Description string
-	RecordType  UsageRecordType
-	Shared      bool
+	CreatedAt   time.Time       `json:"createdAt"`
+	LastUsedAt  *time.Time      `json:"lastUsedAt"`
+	UsageCount  int             `json:"usageCount"`
+	Parents     []string        `json:"parents"`
+	Description string          `json:"description"`
+	RecordType  UsageRecordType `json:"recordType"`
+	Shared      bool            `json:"shared"`
 }
 
 func (c *Client) DiskUsage(ctx context.Context, opts ...DiskUsageOption) ([]*UsageInfo, error) {

client/info.go

@@ -9,13 +9,13 @@ import (
 )
 
 type Info struct {
-	BuildkitVersion BuildkitVersion
+	BuildkitVersion BuildkitVersion `json:"buildkitVersion"`
 }
 
 type BuildkitVersion struct {
-	Package  string
-	Version  string
-	Revision string
+	Package  string `json:"package"`
+	Version  string `json:"version"`
+	Revision string `json:"revision"`
 }
 
 func (c *Client) Info(ctx context.Context) (*Info, error) {

cmd/buildctl/common/common.go

@@ -1,10 +1,14 @@
 package common
 
 import (
+	"bytes"
 	"context"
+	"encoding/json"
 	"net/url"
 	"os"
 	"path/filepath"
+	"strings"
+	"text/template"
 	"time"
 
 	"github.com/moby/buildkit/client"
@@ -88,3 +92,25 @@ func ResolveClient(c *cli.Context) (*client.Client, error) {
 
 	return client.New(ctx, c.GlobalString("addr"), opts...)
 }
+
+func ParseTemplate(format string) (*template.Template, error) {
+	// aliases is from https://github.com/containerd/nerdctl/blob/v0.17.1/cmd/nerdctl/fmtutil.go#L116-L126 (Apache License 2.0)
+	aliases := map[string]string{
+		"json": "{{json .}}",
+	}
+	if alias, ok := aliases[format]; ok {
+		format = alias
+	}
+	// funcs is from https://github.com/docker/cli/blob/v20.10.12/templates/templates.go#L12-L20 (Apache License 2.0)
+	funcs := template.FuncMap{
+		"json": func(v interface{}) string {
+			buf := &bytes.Buffer{}
+			enc := json.NewEncoder(buf)
+			enc.SetEscapeHTML(false)
+			enc.Encode(v)
+			// Remove the trailing new line added by the encoder
+			return strings.TrimSpace(buf.String())
+		},
+	}
+	return template.New("").Funcs(funcs).Parse(format)
+}

cmd/buildctl/debug/info.go

@@ -13,6 +13,12 @@ var InfoCommand = cli.Command{
 	Name:   "info",
 	Usage:  "display internal information",
 	Action: info,
+	Flags: []cli.Flag{
+		cli.StringFlag{
+			Name:  "format",
+			Usage: "Format the output using the given Go template, e.g, '{{json .}}'",
+		},
+	},
 }
 
 func info(clicontext *cli.Context) error {
@@ -24,6 +30,18 @@ func info(clicontext *cli.Context) error {
 	if err != nil {
 		return err
 	}
+	if format := clicontext.String("format"); format != "" {
+		tmpl, err := bccommon.ParseTemplate(format)
+		if err != nil {
+			return err
+		}
+		if err := tmpl.Execute(clicontext.App.Writer, res); err != nil {
+			return err
+		}
+		_, err = fmt.Fprintf(clicontext.App.Writer, "\n")
+		return err
+	}
+
 	w := tabwriter.NewWriter(os.Stdout, 0, 0, 1, ' ', 0)
 	_, _ = fmt.Fprintf(w, "BuildKit:\t%s %s %s\n", res.BuildkitVersion.Package, res.BuildkitVersion.Version, res.BuildkitVersion.Revision)
 	return w.Flush()

cmd/buildctl/debug/workers.go

@@ -1,15 +1,12 @@
 package debug
 
 import (
-	"bytes"
 	"context"
-	"encoding/json"
 	"fmt"
 	"os"
 	"sort"
 	"strings"
 	"text/tabwriter"
-	"text/template"
 
 	"github.com/containerd/containerd/platforms"
 	"github.com/moby/buildkit/client"
@@ -54,7 +51,7 @@ func listWorkers(clicontext *cli.Context) error {
 		if clicontext.Bool("verbose") {
 			logrus.Debug("Ignoring --verbose")
 		}
-		tmpl, err := parseTemplate(format)
+		tmpl, err := bccommon.ParseTemplate(format)
 		if err != nil {
 			return err
 		}
@@ -137,25 +134,3 @@ func joinPlatforms(p []ocispecs.Platform) string {
 	}
 	return strings.Join(str, ",")
 }
-
-func parseTemplate(format string) (*template.Template, error) {
-	// aliases is from https://github.com/containerd/nerdctl/blob/v0.17.1/cmd/nerdctl/fmtutil.go#L116-L126 (Apache License 2.0)
-	aliases := map[string]string{
-		"json": "{{json .}}",
-	}
-	if alias, ok := aliases[format]; ok {
-		format = alias
-	}
-	// funcs is from https://github.com/docker/cli/blob/v20.10.12/templates/templates.go#L12-L20 (Apache License 2.0)
-	funcs := template.FuncMap{
-		"json": func(v interface{}) string {
-			buf := &bytes.Buffer{}
-			enc := json.NewEncoder(buf)
-			enc.SetEscapeHTML(false)
-			enc.Encode(v)
-			// Remove the trailing new line added by the encoder
-			return strings.TrimSpace(buf.String())
-		},
-	}
-	return template.New("").Funcs(funcs).Parse(format)
-}

cmd/buildctl/diskusage.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/moby/buildkit/client"
 	bccommon "github.com/moby/buildkit/cmd/buildctl/common"
+	"github.com/sirupsen/logrus"
 	"github.com/tonistiigi/units"
 	"github.com/urfave/cli"
 )
@@ -26,6 +27,10 @@ var diskUsageCommand = cli.Command{
 			Name:  "verbose, v",
 			Usage: "Verbose output",
 		},
+		cli.StringFlag{
+			Name:  "format",
+			Usage: "Format the output using the given Go template, e.g, '{{json .}}'",
+		},
 	},
 }
 
@@ -40,6 +45,21 @@ func diskUsage(clicontext *cli.Context) error {
 		return err
 	}
 
+	if format := clicontext.String("format"); format != "" {
+		if clicontext.Bool("verbose") {
+			logrus.Debug("Ignoring --verbose")
+		}
+		tmpl, err := bccommon.ParseTemplate(format)
+		if err != nil {
+			return err
+		}
+		if err := tmpl.Execute(clicontext.App.Writer, du); err != nil {
+			return err
+		}
+		_, err = fmt.Fprintf(clicontext.App.Writer, "\n")
+		return err
+	}
+
 	tw := tabwriter.NewWriter(os.Stdout, 1, 8, 1, '\t', 0)
 
 	if clicontext.Bool("verbose") {

cmd/buildctl/prune.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/moby/buildkit/client"
 	bccommon "github.com/moby/buildkit/cmd/buildctl/common"
+	"github.com/sirupsen/logrus"
 	"github.com/tonistiigi/units"
 	"github.com/urfave/cli"
 )
@@ -36,6 +37,10 @@ var pruneCommand = cli.Command{
 			Name:  "verbose, v",
 			Usage: "Verbose output",
 		},
+		cli.StringFlag{
+			Name:  "format",
+			Usage: "Format the output using the given Go template, e.g, '{{json .}}'",
+		},
 	},
 }
 
@@ -47,27 +52,7 @@ func prune(clicontext *cli.Context) error {
 
 	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 clicontext.Bool("verbose") {
-				printVerbose(tw, []*client.UsageInfo{&du})
-			} else {
-				if first {
-					printTableHeader(tw)
-					first = false
-				}
-				printTableRow(tw, &du)
-				tw.Flush()
-			}
-		}
-	}()
+	var summarizer func()
 
 	opts := []client.PruneOption{
 		client.WithFilter(clicontext.StringSlice("filter")),
@@ -78,16 +63,61 @@ func prune(clicontext *cli.Context) error {
 		opts = append(opts, client.PruneAll)
 	}
 
+	if format := clicontext.String("format"); format != "" {
+		if clicontext.Bool("verbose") {
+			logrus.Debug("Ignoring --verbose")
+		}
+		tmpl, err := bccommon.ParseTemplate(format)
+		if err != nil {
+			return err
+		}
+		go func() {
+			defer close(printed)
+			for du := range ch {
+				// Unlike `buildctl du`, the template is applied to a UsageInfo, not to a slice of UsageInfo
+				if err := tmpl.Execute(clicontext.App.Writer, du); err != nil {
+					panic(err)
+				}
+				if _, err = fmt.Fprintf(clicontext.App.Writer, "\n"); err != nil {
+					panic(err)
+				}
+			}
+		}()
+	} else {
+		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 clicontext.Bool("verbose") {
+					printVerbose(tw, []*client.UsageInfo{&du})
+				} else {
+					if first {
+						printTableHeader(tw)
+						first = false
+					}
+					printTableRow(tw, &du)
+					tw.Flush()
+				}
+			}
+		}()
+		summarizer = func() {
+			tw = tabwriter.NewWriter(os.Stdout, 1, 8, 1, '\t', 0)
+			fmt.Fprintf(tw, "Total:\t%.2f\n", units.Bytes(total))
+			tw.Flush()
+		}
+	}
+
 	err = c.Prune(bccommon.CommandContext(clicontext), ch, opts...)
 	close(ch)
 	<-printed
 	if err != nil {
 		return err
 	}
-
-	tw = tabwriter.NewWriter(os.Stdout, 1, 8, 1, '\t', 0)
-	fmt.Fprintf(tw, "Total:\t%.2f\n", units.Bytes(total))
-	tw.Flush()
-
+	if summarizer != nil {
+		summarizer()
+	}
 	return nil
 }