Add "podman volume" command

Add support for podman volume and its subcommands.
The commands supported are:
	podman volume create
	podman volume inspect
	podman volume ls
	podman volume rm
	podman volume prune

This is a tool to manage volumes used by podman. For now it only handle
named volumes, but eventually it will handle all volumes used by podman.

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

1 files changed, 308 insertions, 0 deletions

diff --git a/cmd/podman/volume_ls.go b/cmd/podman/volume_ls.go
new file mode 100644
index 000000000..0f94549ee
--- /dev/null
+++ b/cmd/podman/volume_ls.go
@@ -0,0 +1,308 @@
+package main
+
+import (
+	"reflect"
+	"strings"
+
+	"github.com/containers/libpod/cmd/podman/formats"
+	"github.com/containers/libpod/cmd/podman/libpodruntime"
+	"github.com/containers/libpod/libpod"
+	"github.com/pkg/errors"
+	"github.com/urfave/cli"
+)
+
+// volumeOptions is the "ls" command options
+type volumeLsOptions struct {
+	Format string
+	Quiet  bool
+}
+
+// volumeLsTemplateParams is the template parameters to list the volumes
+type volumeLsTemplateParams struct {
+	Name       string
+	Labels     string
+	MountPoint string
+	Driver     string
+	Options    string
+	Scope      string
+}
+
+// volumeLsJSONParams is the JSON parameters to list the volumes
+type volumeLsJSONParams struct {
+	Name       string            `json:"name"`
+	Labels     map[string]string `json:"labels"`
+	MountPoint string            `json:"mountPoint"`
+	Driver     string            `json:"driver"`
+	Options    map[string]string `json:"options"`
+	Scope      string            `json:"scope"`
+}
+
+var volumeLsDescription = `
+podman volume ls
+
+List all available volumes. The output of the volumes can be filtered
+and the output format can be changed to JSON or a user specified Go template.
+`
+
+var volumeLsFlags = []cli.Flag{
+	cli.StringFlag{
+		Name:  "filter, f",
+		Usage: "Filter volume output",
+	},
+	cli.StringFlag{
+		Name:  "format",
+		Usage: "Format volume output using Go template",
+		Value: "table {{.Driver}}\t{{.Name}}",
+	},
+	cli.BoolFlag{
+		Name:  "quiet, q",
+		Usage: "Print volume output in quiet mode",
+	},
+}
+
+var volumeLsCommand = cli.Command{
+	Name:                   "ls",
+	Aliases:                []string{"list"},
+	Usage:                  "List volumes",
+	Description:            volumeLsDescription,
+	Flags:                  volumeLsFlags,
+	Action:                 volumeLsCmd,
+	SkipArgReorder:         true,
+	UseShortOptionHandling: true,
+}
+
+func volumeLsCmd(c *cli.Context) error {
+	if err := validateFlags(c, volumeLsFlags); err != nil {
+		return err
+	}
+
+	runtime, err := libpodruntime.GetRuntime(c)
+	if err != nil {
+		return errors.Wrapf(err, "error creating libpod runtime")
+	}
+	defer runtime.Shutdown(false)
+
+	if len(c.Args()) > 0 {
+		return errors.Errorf("too many arguments, ls takes no arguments")
+	}
+
+	opts := volumeLsOptions{
+		Quiet: c.Bool("quiet"),
+	}
+	opts.Format = genVolLsFormat(c)
+
+	// Get the filter functions based on any filters set
+	var filterFuncs []libpod.VolumeFilter
+	if c.String("filter") != "" {
+		filters := strings.Split(c.String("filter"), ",")
+		for _, f := range filters {
+			filterSplit := strings.Split(f, "=")
+			if len(filterSplit) < 2 {
+				return errors.Errorf("filter input must be in the form of filter=value: %s is invalid", f)
+			}
+			generatedFunc, err := generateVolumeFilterFuncs(filterSplit[0], filterSplit[1], runtime)
+			if err != nil {
+				return errors.Wrapf(err, "invalid filter")
+			}
+			filterFuncs = append(filterFuncs, generatedFunc)
+		}
+	}
+
+	volumes, err := runtime.GetAllVolumes()
+	if err != nil {
+		return err
+	}
+
+	// Get the volumes that match the filter
+	volsFiltered := make([]*libpod.Volume, 0, len(volumes))
+	for _, vol := range volumes {
+		include := true
+		for _, filter := range filterFuncs {
+			include = include && filter(vol)
+		}
+
+		if include {
+			volsFiltered = append(volsFiltered, vol)
+		}
+	}
+	return generateVolLsOutput(volsFiltered, opts, runtime)
+}
+
+// generate the template based on conditions given
+func genVolLsFormat(c *cli.Context) string {
+	var format string
+	if c.String("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"
+		format = strings.Replace(c.String("format"), `\t`, "\t", -1)
+	}
+	if c.Bool("quiet") {
+		format = "{{.Name}}"
+	}
+	return format
+}
+
+// Convert output to genericParams for printing
+func volLsToGeneric(templParams []volumeLsTemplateParams, JSONParams []volumeLsJSONParams) (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 accurate header based on template given
+func (vol *volumeLsTemplateParams) volHeaderMap() map[string]string {
+	v := reflect.Indirect(reflect.ValueOf(vol))
+	values := make(map[string]string)
+
+	for i := 0; i < v.NumField(); i++ {
+		key := v.Type().Field(i).Name
+		value := key
+		if value == "Name" {
+			value = "Volume" + value
+		}
+		values[key] = strings.ToUpper(splitCamelCase(value))
+	}
+	return values
+}
+
+// getVolTemplateOutput returns all the volumes in the volumeLsTemplateParams format
+func getVolTemplateOutput(lsParams []volumeLsJSONParams, opts volumeLsOptions) ([]volumeLsTemplateParams, error) {
+	var lsOutput []volumeLsTemplateParams
+
+	for _, lsParam := range lsParams {
+		var (
+			labels  string
+			options string
+		)
+
+		for k, v := range lsParam.Labels {
+			label := k
+			if v != "" {
+				label += "=" + v
+			}
+			labels += label
+		}
+		for k, v := range lsParam.Options {
+			option := k
+			if v != "" {
+				option += "=" + v
+			}
+			options += option
+		}
+		params := volumeLsTemplateParams{
+			Name:       lsParam.Name,
+			Driver:     lsParam.Driver,
+			MountPoint: lsParam.MountPoint,
+			Scope:      lsParam.Scope,
+			Labels:     labels,
+			Options:    options,
+		}
+
+		lsOutput = append(lsOutput, params)
+	}
+	return lsOutput, nil
+}
+
+// getVolJSONParams returns the volumes in JSON format
+func getVolJSONParams(volumes []*libpod.Volume, opts volumeLsOptions, runtime *libpod.Runtime) ([]volumeLsJSONParams, error) {
+	var lsOutput []volumeLsJSONParams
+
+	for _, volume := range volumes {
+		params := volumeLsJSONParams{
+			Name:       volume.Name(),
+			Labels:     volume.Labels(),
+			MountPoint: volume.MountPoint(),
+			Driver:     volume.Driver(),
+			Options:    volume.Options(),
+			Scope:      volume.Scope(),
+		}
+
+		lsOutput = append(lsOutput, params)
+	}
+	return lsOutput, nil
+}
+
+// generateVolLsOutput generates the output based on the format, JSON or Go Template, and prints it out
+func generateVolLsOutput(volumes []*libpod.Volume, opts volumeLsOptions, runtime *libpod.Runtime) error {
+	if len(volumes) == 0 && opts.Format != formats.JSONString {
+		return nil
+	}
+	lsOutput, err := getVolJSONParams(volumes, opts, runtime)
+	if err != nil {
+		return err
+	}
+	var out formats.Writer
+
+	switch opts.Format {
+	case formats.JSONString:
+		if err != nil {
+			return errors.Wrapf(err, "unable to create JSON for volume output")
+		}
+		out = formats.JSONStructArray{Output: volLsToGeneric([]volumeLsTemplateParams{}, lsOutput)}
+	default:
+		lsOutput, err := getVolTemplateOutput(lsOutput, opts)
+		if err != nil {
+			return errors.Wrapf(err, "unable to create volume output")
+		}
+		out = formats.StdoutTemplateArray{Output: volLsToGeneric(lsOutput, []volumeLsJSONParams{}), Template: opts.Format, Fields: lsOutput[0].volHeaderMap()}
+	}
+	return formats.Writer(out).Out()
+}
+
+// generateVolumeFilterFuncs returns the true if the volume matches the filter set, otherwise it returns false.
+func generateVolumeFilterFuncs(filter, filterValue string, runtime *libpod.Runtime) (func(volume *libpod.Volume) bool, error) {
+	switch filter {
+	case "name":
+		return func(v *libpod.Volume) bool {
+			return strings.Contains(v.Name(), filterValue)
+		}, nil
+	case "driver":
+		return func(v *libpod.Volume) bool {
+			return v.Driver() == filterValue
+		}, nil
+	case "scope":
+		return func(v *libpod.Volume) bool {
+			return v.Scope() == filterValue
+		}, nil
+	case "label":
+		filterArray := strings.SplitN(filterValue, "=", 2)
+		filterKey := filterArray[0]
+		if len(filterArray) > 1 {
+			filterValue = filterArray[1]
+		} else {
+			filterValue = ""
+		}
+		return func(v *libpod.Volume) bool {
+			for labelKey, labelValue := range v.Labels() {
+				if labelKey == filterKey && ("" == filterValue || labelValue == filterValue) {
+					return true
+				}
+			}
+			return false
+		}, nil
+	case "opt":
+		filterArray := strings.SplitN(filterValue, "=", 2)
+		filterKey := filterArray[0]
+		if len(filterArray) > 1 {
+			filterValue = filterArray[1]
+		} else {
+			filterValue = ""
+		}
+		return func(v *libpod.Volume) bool {
+			for labelKey, labelValue := range v.Options() {
+				if labelKey == filterKey && ("" == filterValue || labelValue == filterValue) {
+					return true
+				}
+			}
+			return false
+		}, nil
+	}
+	return nil, errors.Errorf("%s is an invalid filter", filter)
+}