Merge pull request #819 from umohnani8/kpod_history

Modify the JSON output of kpod history

cmd/kpod/history.go

@@ -1,20 +1,19 @@
 package main
 
 import (
-	"encoding/json"
-	"fmt"
 	"reflect"
 	"strconv"
 	"strings"
 	"time"
 
 	is "github.com/containers/image/storage"
+	"github.com/containers/image/types"
 	"github.com/containers/storage"
 	units "github.com/docker/go-units"
 	"github.com/kubernetes-incubator/cri-o/cmd/kpod/formats"
 	"github.com/kubernetes-incubator/cri-o/libpod/common"
+	"github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
-	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
 )
 
@@ -23,12 +22,24 @@ const (
 	idTruncLength        = 13
 )
 
-// historyOutputParams stores info about each layer
+// historyTemplateParams stores info about each layer
-type historyOutputParams struct {
+type historyTemplateParams struct {
+	ID        string
+	Created   string
+	CreatedBy string
+	Size      string
+	Comment   string
+}
+
+// historyJSONParams is only used when the JSON format is specified,
+// and is better for data processing from JSON.
+// historyJSONParams will be populated by data from v1.History and types.BlobInfo,
+// the members of the struct are the sama data types as their sources.
+type historyJSONParams struct {
 	ID        string     `json:"id"`
-	Created   string `json:"created"`
+	Created   *time.Time `json:"created"`
-	CreatedBy string `json:"createdby"`
+	CreatedBy string     `json:"createdBy"`
-	Size      string `json:"size"`
+	Size      int64      `json:"size"`
 	Comment   string     `json:"comment"`
 }
 
@@ -36,14 +47,14 @@ type historyOutputParams struct {
 type historyOptions struct {
 	image   string
 	human   bool
-	truncate bool
+	noTrunc bool
 	quiet   bool
 	format  string
 }
 
 var (
 	historyFlags = []cli.Flag{
-		cli.BoolFlag{
+		cli.BoolTFlag{
 			Name:  "human, H",
 			Usage: "Display sizes and dates in human readable format",
 		},
@@ -83,226 +94,179 @@ func historyCmd(c *cli.Context) error {
 		return err
 	}
 
-	human := true
+	format := genHistoryFormat(c.Bool("quiet"))
-	if c.IsSet("human") {
-		human = c.Bool("human")
-	}
-
-	truncate := true
-	if c.IsSet("no-trunc") {
-		truncate = !c.Bool("no-trunc")
-	}
-	quiet := false
-	if c.IsSet("quiet") {
-		quiet = c.Bool("quiet")
-	}
-	format := ""
 	if c.IsSet("format") {
 		format = c.String("format")
 	}
+
 	args := c.Args()
 	if len(args) == 0 {
-		logrus.Errorf("an image name must be specified")
+		return errors.Errorf("an image name must be specified")
-		return nil
 	}
 	if len(args) > 1 {
-		logrus.Errorf("Kpod history takes at most 1 argument")
+		return errors.Errorf("Kpod history takes at most 1 argument")
-		return nil
 	}
 	imgName := args[0]
 
 	opts := historyOptions{
 		image:   imgName,
-		human:    human,
+		human:   c.BoolT("human"),
-		truncate: truncate,
+		noTrunc: c.Bool("no-trunc"),
-		quiet:    quiet,
+		quiet:   c.Bool("quiet"),
 		format:  format,
 	}
-	err = outputHistory(store, opts)
+	return generateHistoryOutput(store, opts)
-	return err
 }
 
-func genHistoryFormat(quiet, truncate, human bool) (format string) {
+func genHistoryFormat(quiet bool) (format string) {
 	if quiet {
 		return formats.IDString
 	}
+	return "table {{.ID}}\t{{.Created}}\t{{.CreatedBy}}\t{{.Size}}\t{{.Comment}}\t"
+}
 
-	if truncate {
+// historyToGeneric makes an empty array of interfaces for output
-		format = "table {{ .ID | printf \"%-12.12s\" }} {{ .Created | printf \"%-16s\" }} {{ .CreatedBy | " +
+func historyToGeneric(templParams []historyTemplateParams, JSONParams []historyJSONParams) (genericParams []interface{}) {
-			"printf \"%-45.45s\" }} {{ .Size | printf \"%-16s\" }} {{ .Comment | printf \"%s\" }}"
+	if len(templParams) > 0 {
-	} else {
+		for _, v := range templParams {
-		format = "table {{ .ID | printf \"%-64s\" }} {{ .Created | printf \"%-18s\" }} {{ .CreatedBy | " +
+			genericParams = append(genericParams, interface{}(v))
-			"printf \"%-60s\" }} {{ .Size | printf \"%-16s\" }} {{ .Comment | printf \"%s\"}}"
+		}
+		return
+	}
+	for _, v := range JSONParams {
+		genericParams = append(genericParams, interface{}(v))
 	}
 	return
 }
 
-// outputTime displays the time stamp in "2017-06-20T20:24:10Z" format
+// generate the header based on the template provided
-func outputTime(tm *time.Time) string {
+func (h *historyTemplateParams) headerMap() map[string]string {
-	return tm.Format(time.RFC3339)
+	v := reflect.Indirect(reflect.ValueOf(h))
+	values := make(map[string]string)
+	for h := 0; h < v.NumField(); h++ {
+		key := v.Type().Field(h).Name
+		value := key
+		values[key] = strings.ToUpper(splitCamelCase(value))
+	}
+	return values
 }
 
-// outputHumanTime displays the time elapsed since creation
+// getHistory gets the history of an image and information about its layers
-func outputHumanTime(tm *time.Time) string {
+func getHistory(store storage.Store, image string) ([]v1.History, []types.BlobInfo, string, error) {
-	return units.HumanDuration(time.Since(*tm))
+	ref, err := is.Transport.ParseStoreReference(store, image)
-}
-
-// createJSON retrieves the history of the image and returns a JSON object
-func createJSON(store storage.Store, opts historyOptions) ([]byte, error) {
-	var (
-		size        int64
-		img         *storage.Image
-		imageID     string
-		layerAll    []historyOutputParams
-		createdTime string
-		outputSize  string
-	)
-
-	ref, err := is.Transport.ParseStoreReference(store, opts.image)
 	if err != nil {
-		return nil, errors.Errorf("error parsing reference to image %q: %v", opts.image, err)
+		return nil, nil, "", errors.Wrapf(err, "error parsing reference to image %q", image)
 	}
 
-	img, err = is.Transport.GetStoreImage(store, ref)
+	img, err := is.Transport.GetStoreImage(store, ref)
 	if err != nil {
-		return nil, errors.Errorf("no such image %q: %v", opts.image, err)
+		return nil, nil, "", errors.Wrapf(err, "no such image %q", image)
 	}
 
 	systemContext := common.GetSystemContext("")
 
 	src, err := ref.NewImage(systemContext)
 	if err != nil {
-		return nil, errors.Errorf("error instantiating image %q: %v", opts.image, err)
+		return nil, nil, "", errors.Wrapf(err, "error instantiating image %q", image)
 	}
 
 	oci, err := src.OCIConfig()
 	if err != nil {
-		return nil, err
+		return nil, nil, "", err
 	}
 
-	history := oci.History
+	return oci.History, src.LayerInfos(), img.ID, nil
-	layers := src.LayerInfos()
+}
-	count := 1
+
-	// iterating backwards to get newwest to oldest
+// getHistorytemplateOutput gets the modified history information to be printed in human readable format
+func getHistoryTemplateOutput(history []v1.History, layers []types.BlobInfo, imageID string, opts historyOptions) (historyOutput []historyTemplateParams) {
+	var (
+		outputSize  string
+		createdTime string
+		createdBy   string
+		count       = 1
+	)
 	for i := len(history) - 1; i >= 0; i-- {
-		if i == len(history)-1 {
+		if i != len(history)-1 {
-			imageID = img.ID
-		} else {
 			imageID = "<missing>"
 		}
+		if !opts.noTrunc && i == len(history)-1 {
+			imageID = imageID[:idTruncLength]
+		}
 
+		var size int64
 		if !history[i].EmptyLayer {
 			size = layers[len(layers)-count].Size
 			count++
-		} else {
-			size = 0
 		}
 
 		if opts.human {
-			createdTime = outputHumanTime(history[i].Created) + " ago"
+			createdTime = units.HumanDuration(time.Since((*history[i].Created))) + " ago"
 			outputSize = units.HumanSize(float64(size))
 		} else {
-			createdTime = outputTime(history[i].Created)
+			createdTime = (history[i].Created).Format(time.RFC3339)
 			outputSize = strconv.FormatInt(size, 10)
 		}
-		params := historyOutputParams{
+
+		createdBy = strings.Join(strings.Fields(history[i].CreatedBy), " ")
+		if !opts.noTrunc && len(createdBy) > createdByTruncLength {
+			createdBy = createdBy[:createdByTruncLength-3] + "..."
+		}
+
+		params := historyTemplateParams{
 			ID:        imageID,
 			Created:   createdTime,
-			CreatedBy: history[i].CreatedBy,
+			CreatedBy: createdBy,
 			Size:      outputSize,
 			Comment:   history[i].Comment,
 		}
-
-		layerAll = append(layerAll, params)
-	}
-
-	output, err := json.MarshalIndent(layerAll, "", "\t\t")
-	if err != nil {
-		return nil, errors.Errorf("error marshalling to JSON: %v", err)
-	}
-
-	if err = src.Close(); err != nil {
-		return nil, err
-	}
-
-	return output, nil
-}
-
-// historyToGeneric makes an empty array of interfaces for output
-func historyToGeneric(params []historyOutputParams) []interface{} {
-	genericParams := make([]interface{}, len(params))
-	for i, v := range params {
-		genericParams[i] = interface{}(v)
-	}
-	return genericParams
-}
-
-// outputHistory gets the history of the image from the JSON object
-// and pretty prints it to the screen
-func outputHistory(store storage.Store, opts historyOptions) error {
-	var (
-		outputCreatedBy string
-		imageID         string
-		history         []historyOutputParams
-	)
-
-	raw, err := createJSON(store, opts)
-	if err != nil {
-		return errors.Errorf("error creating JSON: %v", err)
-	}
-
-	if err = json.Unmarshal(raw, &history); err != nil {
-		return errors.Errorf("error Unmarshalling JSON: %v", err)
-	}
-
-	historyOutput := []historyOutputParams{}
-
-	historyFormat := opts.format
-	if historyFormat == "" {
-		historyFormat = genHistoryFormat(opts.quiet, opts.truncate, opts.human)
-	}
-
-	for i := 0; i < len(history); i++ {
-		imageID = history[i].ID
-
-		outputCreatedBy = strings.Join(strings.Fields(history[i].CreatedBy), " ")
-		if opts.truncate && len(outputCreatedBy) > createdByTruncLength {
-			outputCreatedBy = outputCreatedBy[:createdByTruncLength-3] + "..."
-		}
-
-		if opts.truncate && i == 0 {
-			imageID = history[i].ID[:idTruncLength]
-		}
-
-		params := historyOutputParams{
-			ID:        imageID,
-			Created:   history[i].Created,
-			CreatedBy: outputCreatedBy,
-			Size:      history[i].Size,
-			Comment:   history[i].Comment,
-		}
 		historyOutput = append(historyOutput, params)
 	}
+	return
+}
+
+// getHistoryJSONOutput returns the history information in its raw form
+func getHistoryJSONOutput(history []v1.History, layers []types.BlobInfo, imageID string) (historyOutput []historyJSONParams) {
+	count := 1
+	for i := len(history) - 1; i >= 0; i-- {
+		var size int64
+		if !history[i].EmptyLayer {
+			size = layers[len(layers)-count].Size
+			count++
+		}
+
+		params := historyJSONParams{
+			ID:        imageID,
+			Created:   history[i].Created,
+			CreatedBy: history[i].CreatedBy,
+			Size:      size,
+			Comment:   history[i].Comment,
+		}
+		historyOutput = append(historyOutput, params)
+	}
+	return
+}
+
+// generateHistoryOutput generates the history based on the format given
+func generateHistoryOutput(store storage.Store, opts historyOptions) error {
+	history, layers, imageID, err := getHistory(store, opts.image)
+	if err != nil {
+		return errors.Wrapf(err, "error getting history of image %q", opts.image)
+	}
+	if len(history) == 0 {
+		return nil
+	}
 
 	var out formats.Writer
+
 	switch opts.format {
 	case formats.JSONString:
-		out = formats.JSONStructArray{Output: historyToGeneric(historyOutput)}
+		historyOutput := getHistoryJSONOutput(history, layers, imageID)
+		out = formats.JSONStructArray{Output: historyToGeneric([]historyTemplateParams{}, historyOutput)}
 	default:
-		out = formats.StdoutTemplateArray{Output: historyToGeneric(historyOutput), Template: historyFormat, Fields: historyOutput[0].headerMap()}
+		historyOutput := getHistoryTemplateOutput(history, layers, imageID, opts)
-
+		out = formats.StdoutTemplateArray{Output: historyToGeneric(historyOutput, []historyJSONParams{}), Template: opts.format, Fields: historyOutput[0].headerMap()}
 	}
-	formats.Writer(out).Out()
-	return nil
-}
 
-func (h *historyOutputParams) headerMap() map[string]string {
+	return formats.Writer(out).Out()
-	v := reflect.Indirect(reflect.ValueOf(h))
-	values := make(map[string]string)
-	for h := 0; h < v.NumField(); h++ {
-		key := v.Type().Field(h).Name
-		value := key
-		values[key] = fmt.Sprintf("%s        ", strings.ToUpper(splitCamelCase(value)))
-	}
-	return values
 }