Add 'kpod history' command

Signed-off-by: umohnani8 <umohnani@redhat.com>

README.md

@@ -41,6 +41,7 @@ It is currently in active development in the Kubernetes community through the [d
 | ---------------------------------------------------- | ---------------------------------------------------------------------------------------------------- |
 | [crio(8)](/docs/crio.8.md)                 | Enable OCI Kubernetes Container Runtime daemon |
 | [kpod(1)](/docs/kpod.1.md)                 | Simple management tool for pods and images |
+| [kpod-history(1)](/docs/kpod-history.1.md)] | Shows the history of an image |
 | [kpod-images(1)](/docs/kpod-images.1.md)   | List images in local storage |
 | [kpod-pull(1)](/docs/kpod-pull.1.md)       | Pull an image from a registry |
 | [kpod-rmi(1)](/docs/kpod-rmi.1.md)         | Removes one or more images   |

cmd/kpod/history.go

@@ -0,0 +1,353 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+	"text/template"
+	"time"
+
+	"os"
+
+	"strconv"
+
+	"github.com/Sirupsen/logrus"
+	is "github.com/containers/image/storage"
+	"github.com/containers/storage"
+	units "github.com/docker/go-units"
+	"github.com/pkg/errors"
+	"github.com/urfave/cli"
+)
+
+const (
+	createdByTruncLength = 45
+	idTruncLength        = 13
+)
+
+// historyOutputParams stores info about each layer
+type historyOutputParams struct {
+	ID        string     `json:"id"`
+	Created   *time.Time `json:"created"`
+	CreatedBy string     `json:"createdby"`
+	Size      int64      `json:"size"`
+	Comment   string     `json:"comment"`
+}
+
+// historyOptions stores cli flag values
+type historyOptions struct {
+	image   string
+	human   bool
+	noTrunc bool
+	quiet   bool
+	format  string
+}
+
+var (
+	historyFlags = []cli.Flag{
+		cli.BoolFlag{
+			Name:  "human, H",
+			Usage: "Display sizes and dates in human readable format",
+		},
+		cli.BoolFlag{
+			Name:  "no-trunc",
+			Usage: "Do not truncate the output",
+		},
+		cli.BoolFlag{
+			Name:  "quiet, q",
+			Usage: "Display the numeric IDs only",
+		},
+		cli.StringFlag{
+			Name:  "format",
+			Usage: "Pretty-print history of the image using a Go template",
+		},
+		cli.BoolFlag{
+			Name:  "json",
+			Usage: "Print the history in JSON format",
+		},
+	}
+
+	historyDescription = "Displays the history of an image. The information can be printed out in an easy to read, " +
+		"or user specified format, and can be truncated."
+	historyCommand = cli.Command{
+		Name:        "history",
+		Usage:       "Show history of a specified image",
+		Description: historyDescription,
+		Flags:       historyFlags,
+		Action:      historyCmd,
+		ArgsUsage:   "",
+	}
+)
+
+func historyCmd(c *cli.Context) error {
+	store, err := getStore(c)
+	if err != nil {
+		return err
+	}
+
+	human := true
+	if c.IsSet("human") {
+		human = c.Bool("human")
+	}
+	noTruncate := false
+	if c.IsSet("no-trunc") {
+		noTruncate = c.Bool("no-trunc")
+	}
+	quiet := false
+	if c.IsSet("quiet") {
+		quiet = c.Bool("quiet")
+	}
+	json := false
+	if c.IsSet("json") {
+		json = c.Bool("json")
+	}
+	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 nil
+	}
+	if len(args) > 1 {
+		logrus.Errorf("Kpod history takes at most 1 argument")
+		return nil
+	}
+	imgName := args[0]
+
+	opts := historyOptions{
+		image:   imgName,
+		human:   human,
+		noTrunc: noTruncate,
+		quiet:   quiet,
+		format:  format,
+	}
+
+	var history []byte
+	if json {
+		history, err = createJSON(store, opts)
+		fmt.Println(string(history))
+	} else {
+		if format == "" && !quiet {
+			outputHeading(noTruncate)
+		}
+		err = outputHistory(store, opts)
+	}
+	return err
+}
+
+// outputHeader outputs the heading
+func outputHeading(noTrunc bool) {
+	if !noTrunc {
+		fmt.Printf("%-12s\t\t%-16s\t\t%-45s\t\t", "IMAGE", "CREATED", "CREATED BY")
+		fmt.Printf("%-16s\t\t%s\n", "SIZE", "COMMENT")
+	} else {
+		fmt.Printf("%-64s\t%-18s\t%-60s\t", "IMAGE", "CREATED", "CREATED BY")
+		fmt.Printf("%-16s\t%s\n", "SIZE", "COMMENT")
+	}
+}
+
+// outputString outputs the information in historyOutputParams
+func outputString(noTrunc, human bool, params historyOutputParams) {
+	var (
+		createdTime string
+		outputSize  string
+	)
+
+	if human {
+		createdTime = outputHumanTime(params.Created) + " ago"
+		outputSize = units.HumanSize(float64(params.Size))
+	} else {
+		createdTime = outputTime(params.Created)
+		outputSize = strconv.FormatInt(params.Size, 10)
+	}
+
+	if !noTrunc {
+		fmt.Printf("%-12.12s\t\t%-16s\t\t%-45.45s\t\t", params.ID, createdTime, params.CreatedBy)
+		fmt.Printf("%-16s\t\t%s\n", outputSize, params.Comment)
+	} else {
+		fmt.Printf("%-64s\t%-18s\t%-60s\t", params.ID, createdTime, params.CreatedBy)
+		fmt.Printf("%-16s\t%s\n\n", outputSize, params.Comment)
+	}
+}
+
+// outputWithTemplate is called when --format is given a template
+func outputWithTemplate(format string, params historyOutputParams, human bool) error {
+	templ, err := template.New("history").Parse(format)
+	if err != nil {
+		return errors.Wrapf(err, "error parsing template")
+	}
+
+	createdTime := outputTime(params.Created)
+	outputSize := strconv.FormatInt(params.Size, 10)
+
+	if human {
+		createdTime = outputHumanTime(params.Created) + " ago"
+		outputSize = units.HumanSize(float64(params.Size))
+	}
+
+	// templParams is used to store the info from params and the time and
+	// size that have been converted to type string for when the human flag
+	// is set
+	templParams := struct {
+		ID        string
+		Created   string
+		CreatedBy string
+		Size      string
+		Comment   string
+	}{
+		params.ID,
+		createdTime,
+		params.CreatedBy,
+		outputSize,
+		params.Comment,
+	}
+
+	if err = templ.Execute(os.Stdout, templParams); err != nil {
+		return err
+	}
+	fmt.Println()
+	return nil
+}
+
+// outputTime displays the time stamp in "2017-06-20T20:24:10Z" format
+func outputTime(tm *time.Time) string {
+	return tm.Format(time.RFC3339)
+}
+
+// outputHumanTime displays the time elapsed since creation
+func outputHumanTime(tm *time.Time) string {
+	return units.HumanDuration(time.Since(*tm))
+}
+
+// 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
+	)
+
+	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)
+	}
+
+	img, err = is.Transport.GetStoreImage(store, ref)
+	if err != nil {
+		return nil, errors.Errorf("no such image %q: %v", opts.image, err)
+	}
+
+	systemContext := getSystemContext("")
+
+	src, err := ref.NewImage(systemContext)
+	if err != nil {
+		return nil, errors.Errorf("error instantiating image %q: %v", opts.image, err)
+	}
+
+	oci, err := src.OCIConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	history := oci.History
+	layers := src.LayerInfos()
+	count := 1
+	// iterating backwards to get newwest to oldest
+	for i := len(history) - 1; i >= 0; i-- {
+		if i == len(history)-1 {
+			imageID = img.ID
+		} else {
+			imageID = "<missing>"
+		}
+
+		if !history[i].EmptyLayer {
+			size = layers[len(layers)-count].Size
+			count++
+		} else {
+			size = 0
+		}
+
+		params := historyOutputParams{
+			ID:        imageID,
+			Created:   history[i].Created,
+			CreatedBy: history[i].CreatedBy,
+			Size:      size,
+			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
+}
+
+// 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)
+	}
+
+	for i := 0; i < len(history); i++ {
+		imageID = history[i].ID
+
+		outputCreatedBy = strings.Join(strings.Fields(history[i].CreatedBy), " ")
+		if !opts.noTrunc && len(outputCreatedBy) > createdByTruncLength {
+			outputCreatedBy = outputCreatedBy[:createdByTruncLength-3] + "..."
+		}
+
+		if !opts.noTrunc && i == 0 {
+			imageID = history[i].ID[:idTruncLength]
+		}
+
+		if opts.quiet {
+			if !opts.noTrunc {
+				fmt.Printf("%-12.12s\n", imageID)
+			} else {
+				fmt.Printf("%-s\n", imageID)
+			}
+			continue
+		}
+
+		params := historyOutputParams{
+			ID:        imageID,
+			Created:   history[i].Created,
+			CreatedBy: outputCreatedBy,
+			Size:      history[i].Size,
+			Comment:   history[i].Comment,
+		}
+
+		if len(opts.format) > 0 {
+			if err = outputWithTemplate(opts.format, params, opts.human); err != nil {
+				return errors.Errorf("error outputing with template: %v", err)
+			}
+			continue
+		}
+
+		outputString(opts.noTrunc, opts.human, params)
+	}
+	return nil
+}

cmd/kpod/main.go

@@ -28,6 +28,7 @@ func main() {
 		tagCommand,
 		versionCommand,
 		pullCommand,
+		historyCommand,
 	}
 	app.Flags = []cli.Flag{
 		cli.StringFlag{

completions/bash/kpod

@@ -93,6 +93,28 @@ _kpod_pull() {
     _complete_ "$options_with_args" "$boolean_options"
 }
 
+_kpod_history() {
+     local options_with_args="
+     --format
+     "
+     local boolean_options="
+     --human -H
+     --no-trunc
+     --quiet -q
+     --json
+     "
+     _complete_ "$options_with_args" "$boolean_options"
+
+    case "$cur" in
+        -*)
+            COMPREPLY=($(compgen -W "$boolean_options $options_with_args" -- "$cur"))
+            ;;
+        *)
+            __kpod_list_images
+            ;;
+    esac
+}
+
 _kpod_kpod() {
      local options_with_args="
      "
@@ -106,6 +128,7 @@ _kpod_kpod() {
     tag
     version
     pull
+    history
      "
 
      case "$prev" in

docs/kpod-history.1.md

@@ -0,0 +1,69 @@
+% kpod(8) # kpod-history - Simple tool to view the history of an image
+% Urvashi Mohnani
+% JULY 2017
+# NAME
+kpod-history - Shows the history of an image.
+
+# SYNOPSIS
+**kpod history [OPTIONS] IMAGE[:TAG|DIGEST]**
+
+# DESCRIPTION
+**kpod history** displays the history of an image by printing out information
+about each layer used in the image. The information printed out for each layer
+include Created (time and date), Created By, Size, and Comment. The output can
+be truncated or not using the **--no-trunc** flag. If the **--human** flag is
+set, the time of creation and size are printed out in a human readable format.
+The **--quiet** flag displays the ID of the image only when set and the **--format**
+flag is used to print the information using the Go template provided by the user.
+
+Valid placeholders for the Go template are listed below:
+| **Placeholder** | **Description**                                                              |
+|-----------------|------------------------------------------------------------------------------|
+| .ID             | Image ID                                                                     |
+| .Created        | if **--human**, time elapsed since creation, otherwise time stamp of creation|
+| .CreatedBy      | Command used to create the layer                                             |
+| .Size           | Size of layer on disk                                                        |
+| .Comment        | Comment for the layer                                                        |
+
+**kpod [GLOBAL OPTIONS]**
+
+**kpod [GLOBAL OPTIONS] history [OPTIONS]**
+
+# GLOBAL OPTIONS
+
+**--help, -h**
+  Print usage statement
+
+# OPTIONS
+
+**--human, -H**
+    Display sizes and dates in human readable format
+
+**--no-trunc**
+    Do not truncate the output
+
+**--quiet, -q**
+    Print the numeric IDs only
+
+**--format**
+    Pretty-print history of the image using a Go template
+
+**--json**
+    Print the history in JSON form
+
+# COMMANDS
+
+**kpod history debian**
+
+**kpod history --no-trunc=true --human=false debian**
+
+**kpod history --format "{{.ID}} {{.Created}}" debian**
+
+## history
+Show the history of an image
+
+# SEE ALSO
+kpod(1), crio(8), crio.conf(5)
+
+# HISTORY
+July 2017, Originally compiled by Urvashi Mohnani <umohnani@redhat.com>

test/kpod.bats

@@ -2,6 +2,7 @@
 
 load helpers
 
+IMAGE="alpine"
 ROOT="$TESTDIR/crio"
 RUNROOT="$TESTDIR/crio-run"
 KPOD_OPTIONS="--root $ROOT --runroot $RUNROOT --storage-driver vfs"
@@ -16,30 +17,40 @@ KPOD_OPTIONS="--root $ROOT --runroot $RUNROOT --storage-driver vfs"
 	run ${KPOD_BINARY} $KPOD_OPTIONS pull debian:6.0.10
 	echo "$output"
 	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} $KPOD_OPTIONS rmi debian:6.0.10
+	[ "$status" -eq 0 ]
 }
 
 @test "kpod pull from docker without tag" {
 	run ${KPOD_BINARY} $KPOD_OPTIONS pull debian
 	echo "$output"
 	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} $KPOD_OPTIONS rmi debian
+	[ "$status" -eq 0 ]
 }
 
 @test "kpod pull from a non-docker registry with tag" {
 	run ${KPOD_BINARY} $KPOD_OPTIONS pull registry.fedoraproject.org/fedora:rawhide
 	echo "$output"
 	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} $KPOD_OPTIONS rmi registry.fedoraproject.org/fedora:rawhide
+	[ "$status" -eq 0 ]
 }
 
 @test "kpod pull from a non-docker registry without tag" {
 	run ${KPOD_BINARY} $KPOD_OPTIONS pull registry.fedoraproject.org/fedora
 	echo "$output"
 	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} $KPOD_OPTIONS rmi registry.fedoraproject.org/fedora
+	[ "$status" -eq 0 ]
 }
 
 @test "kpod pull using digest" {
-	run ${KPOD_BINARY} $KPOD_OPTIONS pull debian@sha256:7d067f77d2ae5a23fe6920f8fbc2936c4b0d417e9d01b26372561860750815f0
+	run ${KPOD_BINARY} $KPOD_OPTIONS pull alpine@sha256:1072e499f3f655a032e88542330cf75b02e7bdf673278f701d7ba61629ee3ebe
 	echo "$output"
 	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} $KPOD_OPTIONS rmi alpine:latest
+	[ "$status" -eq 0 ]
 }
 
 @test "kpod pull from a non existent image" {
@@ -47,3 +58,62 @@ KPOD_OPTIONS="--root $ROOT --runroot $RUNROOT --storage-driver vfs"
 	echo "$output"
 	[ "$status" -ne 0 ]
 }
+
+@test "kpod history default" {
+	run ${KPOD_BINARY} ${KPOD_OPTIONS} pull $IMAGE
+	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} ${KPOD_OPTIONS} history $IMAGE
+	echo "$output"
+	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} $KPOD_OPTIONS rmi $IMAGE
+	[ "$status" -eq 0 ]
+}
+
+@test "kpod history with format" {
+	run ${KPOD_BINARY} ${KPOD_OPTIONS} pull $IMAGE
+	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} ${KPOD_OPTIONS} history --format "{{.ID}} {{.Created}}" $IMAGE
+	echo "$output"
+	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} $KPOD_OPTIONS rmi $IMAGE
+	[ "$status" -eq 0 ]
+}
+
+@test "kpod history human flag" {
+	run ${KPOD_BINARY} ${KPOD_OPTIONS} pull $IMAGE
+	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} ${KPOD_OPTIONS} history --human=false $IMAGE
+	echo "$output"
+	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} $KPOD_OPTIONS rmi $IMAGE
+	[ "$status" -eq 0 ]
+}
+
+@test "kpod history quiet flag" {
+	run ${KPOD_BINARY} ${KPOD_OPTIONS} pull $IMAGE
+	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} ${KPOD_OPTIONS} history -q $IMAGE
+	echo "$output"
+	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} $KPOD_OPTIONS rmi $IMAGE
+	[ "$status" -eq 0 ]
+}
+
+@test "kpod history no-trunc flag" {
+	run ${KPOD_BINARY} ${KPOD_OPTIONS} pull $IMAGE
+	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} ${KPOD_OPTIONS} history --no-trunc $IMAGE
+	echo "$output"
+	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} $KPOD_OPTIONS rmi $IMAGE
+	[ "$status" -eq 0 ]
+}
+
+@test "kpod history json flag" {
+	run ${KPOD_BINARY} ${KPOD_OPTIONS} pull $IMAGE
+	run bash -c "${KPOD_BINARY} ${KPOD_OPTIONS} history --json $IMAGE | python -m json.tool"
+	echo "$output"
+	[ "$status" -eq 0 ]
+	run ${KPOD_BINARY} $KPOD_OPTIONS rmi $IMAGE
+	[ "$status" -eq 0 ]
+}