Portworx Volume Driver in Kubernetes

- Add a new type PortworxVolumeSource
- Implement the kubernetes volume plugin for Portworx Volumes under pkg/volume/portworx
- The Portworx Volume Driver uses the libopenstorage/openstorage specifications and apis for volume operations.

Changes for k8s configuration and examples for portworx volumes.

- Add PortworxVolume hooks in kubectl, kube-controller-manager and validation.
- Add a README for PortworxVolume usage as PVs, PVCs and StorageClass.
- Add example spec files

Handle code review comments.

- Modified READMEs to incorporate to suggestions.
- Add a test for ReadWriteMany access mode.
- Use util.UnmountPath in TearDown.
- Add ReadOnly flag to PortworxVolumeSource
- Use hostname:port instead of unix sockets
- Delete the mount dir in TearDown.
- Fix link issue in persistentvolumes README
- In unit test check for mountpath after Setup is done.
- Add PVC Claim Name as a Portworx Volume Label

Generated code and documentation.
- Updated swagger spec
- Updated api-reference docs
- Updated generated code under pkg/api/v1

Godeps update for Portworx Volume Driver
- Adds github.com/libopenstorage/openstorage
- Adds go.pedge.io/pb/go/google/protobuf
- Updates Godep Licenses

vendor/github.com/libopenstorage/openstorage/pkg/units/units.go

@@ -0,0 +1,139 @@
+package units
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+const (
+	_ = iota
+	// KiB 1024 bytes
+	KiB = 1 << (10 * iota)
+	// MiB 1024 KiB
+	MiB
+	// GiB 1024 MiB
+	GiB
+	// TiB 1024 GiB
+	TiB
+	// PiB 1024 TiB
+	PiB
+)
+
+const (
+	// KB 1000 bytes
+	KB = 1000
+	// MB 1000 KB
+	MB = KB * 1000
+	// GB 1000 MB
+	GB = MB * 1000
+	// TB 1000 GB
+	TB = GB * 1000
+	// PB 1000 TB
+	PB = TB * 1000
+)
+
+var (
+	unitMap = map[string]int64{
+		"B": 1,
+		"b": 1,
+
+		"KB": KB,
+		"kb": KB,
+		"MB": MB,
+		"mb": MB,
+		"GB": GB,
+		"gb": GB,
+		"TB": TB,
+		"tb": TB,
+		"PB": PB,
+		"pb": PB,
+
+		"K": KiB,
+		"k": KiB,
+		"M": MiB,
+		"m": MiB,
+		"G": GiB,
+		"g": GiB,
+		"T": TiB,
+		"t": TiB,
+		"P": PiB,
+		"p": PiB,
+
+		"KiB": KiB,
+		"MiB": MiB,
+		"GiB": GiB,
+		"TiB": TiB,
+		"PiB": PiB,
+
+		"Mi": MiB,
+		"Gi": GiB,
+		"Ti": TiB,
+		"Pi": PiB,
+	}
+)
+
+var unitPattern = regexp.MustCompile(
+	"([0-9]+)(.[0-9]+)*\\s*(B|b|K|k|M|m|G|g|T|t|P|p|KB|kb|KiB|MB|mb|MiB|Mi|GB|gb|GiB|Gi|TB|tb|TiB|Ti|PB|pb|PiB|Pi|)")
+var BadUnit = errors.New("Bad unit")
+
+func String(b uint64) string {
+	if b > PiB {
+		return fmt.Sprintf("%.2f PiB", float64(b)/float64(PiB))
+	}
+	if b > TiB {
+		return fmt.Sprintf("%.2f TiB", float64(b)/float64(TiB))
+	}
+	if b > GiB {
+		return fmt.Sprintf("%.1f TiB", float64(b)/float64(GiB))
+	}
+	if b > MiB {
+		return fmt.Sprintf("%v MiB", b/MiB)
+	}
+	if b > KiB {
+		return fmt.Sprintf("%v KiB", b/KiB)
+	}
+	return fmt.Sprintf("%v bytes", b)
+}
+
+func Parse(bUnit string) (int64, error) {
+	ustring := strings.TrimSpace(bUnit)
+	unitPattern.Longest()
+	if !unitPattern.MatchString(ustring) {
+		return -1, fmt.Errorf("Unit parse error: %s", bUnit)
+	}
+	matches := unitPattern.FindStringSubmatch(ustring)
+
+	if len(matches) == 0 || len(matches) > 4 {
+		return -1, fmt.Errorf(
+			"Unit parse error: invalid count of fields (%v)",
+			len(matches))
+	}
+	if len(matches) == 1 {
+		return strconv.ParseInt(ustring, 10, 64)
+	}
+	shift := 0
+	if len(matches) == 4 {
+		shift = 1
+	}
+	if len(matches) == 2 {
+		return -1, fmt.Errorf("Unit parse error: invalid fields %v",
+			matches)
+	}
+	if ustring != matches[0] {
+		return -1, fmt.Errorf("Unit parse error: invalid fields %v",
+			matches)
+	}
+	multiplier, ok := unitMap[matches[2+shift]]
+	if !ok {
+		multiplier = unitMap["G"]
+	}
+	base, err := strconv.ParseInt(matches[1], 10, 64)
+	if err != nil {
+		return -1, fmt.Errorf("Invalid number")
+	}
+
+	return base * multiplier, nil
+}