1 files changed, 246 insertions, 0 deletions
diff --git a/cmd/podman/history.go b/cmd/podman/history.go
new file mode 100644
index 000000000..f142f5fd4
--- /dev/null
+++ b/cmd/podman/history.go
@@ -0,0 +1,246 @@
+package main
+
+import (
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/containers/image/types"
+	units "github.com/docker/go-units"
+	"github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+	"github.com/projectatomic/libpod/cmd/podman/formats"
+	"github.com/urfave/cli"
+)
+
+const (
+	createdByTruncLength = 45
+	idTruncLength        = 12
+)
+
+// historyTemplateParams stores info about each layer
+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   *time.Time `json:"created"`
+	CreatedBy string     `json:"createdBy"`
+	Size      int64      `json:"size"`
+	Comment   string     `json:"comment"`
+}
+
+// historyOptions stores cli flag values
+type historyOptions struct {
+	human   bool
+	noTrunc bool
+	quiet   bool
+	format  string
+}
+
+var (
+	historyFlags = []cli.Flag{
+		cli.BoolTFlag{
+			Name:  "human, H",
+			Usage: "Display sizes and dates in human readable format",
+		},
+		cli.BoolFlag{
+			Name:  "no-trunc, notruncate",
+			Usage: "Do not truncate the output",
+		},
+		cli.BoolFlag{
+			Name:  "quiet, q",
+			Usage: "Display the numeric IDs only",
+		},
+		cli.StringFlag{
+			Name:  "format",
+			Usage: "Change the output to JSON or a Go template",
+		},
+	}
+
+	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:              "",
+		UseShortOptionHandling: true,
+	}
+)
+
+func historyCmd(c *cli.Context) error {
+	if err := validateFlags(c, historyFlags); err != nil {
+		return err
+	}
+
+	runtime, err := getRuntime(c)
+	if err != nil {
+		return errors.Wrapf(err, "could not get runtime")
+	}
+	defer runtime.Shutdown(false)
+
+	format := genHistoryFormat(c.String("format"), c.Bool("quiet"))
+
+	args := c.Args()
+	if len(args) == 0 {
+		return errors.Errorf("an image name must be specified")
+	}
+	if len(args) > 1 {
+		return errors.Errorf("podman history takes at most 1 argument")
+	}
+	imgName := args[0]
+
+	opts := historyOptions{
+		human:   c.BoolT("human"),
+		noTrunc: c.Bool("no-trunc"),
+		quiet:   c.Bool("quiet"),
+		format:  format,
+	}
+
+	history, layers, imageID, err := runtime.GetHistory(imgName)
+	if err != nil {
+		return errors.Wrapf(err, "error getting history of image %q", imgName)
+	}
+
+	return generateHistoryOutput(history, layers, imageID, opts)
+}
+
+func genHistoryFormat(format string, quiet bool) string {
+	if format != "" {
+		// "\t" from the command line is not being recognized as a tab
+		// replacing the string "\t" to a tab character if the user passes in "\t"
+		return strings.Replace(format, `\t`, "\t", -1)
+	}
+	if quiet {
+		return formats.IDString
+	}
+	return "table {{.ID}}\t{{.Created}}\t{{.CreatedBy}}\t{{.Size}}\t{{.Comment}}\t"
+}
+
+// historyToGeneric makes an empty array of interfaces for output
+func historyToGeneric(templParams []historyTemplateParams, JSONParams []historyJSONParams) (genericParams []interface{}) {
+	if len(templParams) > 0 {
+		for _, v := range templParams {
+			genericParams = append(genericParams, interface{}(v))
+		}
+		return
+	}
+	for _, v := range JSONParams {
+		genericParams = append(genericParams, interface{}(v))
+	}
+	return
+}
+
+// generate the header based on the template provided
+func (h *historyTemplateParams) headerMap() map[string]string {
+	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
+}
+
+// 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 {
+			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++
+		}
+
+		if opts.human {
+			createdTime = units.HumanDuration(time.Since((*history[i].Created))) + " ago"
+			outputSize = units.HumanSize(float64(size))
+		} else {
+			createdTime = (history[i].Created).Format(time.RFC3339)
+			outputSize = strconv.FormatInt(size, 10)
+		}
+
+		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: createdBy,
+			Size:      outputSize,
+			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(history []v1.History, layers []types.BlobInfo, imageID string, opts historyOptions) error {
+	if len(history) == 0 {
+		return nil
+	}
+
+	var out formats.Writer
+
+	switch opts.format {
+	case formats.JSONString:
+		historyOutput := getHistoryJSONOutput(history, layers, imageID)
+		out = formats.JSONStructArray{Output: historyToGeneric([]historyTemplateParams{}, historyOutput)}
+	default:
+		historyOutput := getHistoryTemplateOutput(history, layers, imageID, opts)
+		out = formats.StdoutTemplateArray{Output: historyToGeneric(historyOutput, []historyJSONParams{}), Template: opts.format, Fields: historyOutput[0].headerMap()}
+	}
+
+	return formats.Writer(out).Out()
+}