Update go dependencies

vendor/k8s.io/kubernetes/pkg/util/BUILD

@@ -13,7 +13,6 @@ go_library(
     srcs = [
         "doc.go",
         "template.go",
-        "umask.go",
         "util.go",
     ],
     tags = ["automanaged"],
@@ -48,24 +47,19 @@ filegroup(
         "//pkg/util/bandwidth:all-srcs",
         "//pkg/util/config:all-srcs",
         "//pkg/util/configz:all-srcs",
-        "//pkg/util/crlf:all-srcs",
         "//pkg/util/dbus:all-srcs",
         "//pkg/util/ebtables:all-srcs",
         "//pkg/util/env:all-srcs",
-        "//pkg/util/errors:all-srcs",
         "//pkg/util/exec:all-srcs",
         "//pkg/util/flock:all-srcs",
-        "//pkg/util/framer:all-srcs",
         "//pkg/util/goroutinemap:all-srcs",
         "//pkg/util/hash:all-srcs",
         "//pkg/util/i18n:all-srcs",
         "//pkg/util/initsystem:all-srcs",
         "//pkg/util/interrupt:all-srcs",
-        "//pkg/util/intstr:all-srcs",
         "//pkg/util/io:all-srcs",
         "//pkg/util/ipconfig:all-srcs",
         "//pkg/util/iptables:all-srcs",
-        "//pkg/util/json:all-srcs",
         "//pkg/util/keymutex:all-srcs",
         "//pkg/util/labels:all-srcs",
         "//pkg/util/limitwriter:all-srcs",
@@ -79,13 +73,10 @@ filegroup(
         "//pkg/util/oom:all-srcs",
         "//pkg/util/parsers:all-srcs",
         "//pkg/util/procfs:all-srcs",
-        "//pkg/util/rand:all-srcs",
         "//pkg/util/removeall:all-srcs",
         "//pkg/util/resourcecontainer:all-srcs",
         "//pkg/util/rlimit:all-srcs",
-        "//pkg/util/runtime:all-srcs",
         "//pkg/util/selinux:all-srcs",
-        "//pkg/util/sets:all-srcs",
         "//pkg/util/slice:all-srcs",
         "//pkg/util/strings:all-srcs",
         "//pkg/util/sysctl:all-srcs",
@@ -95,12 +86,8 @@ filegroup(
         "//pkg/util/term:all-srcs",
         "//pkg/util/threading:all-srcs",
         "//pkg/util/tolerations:all-srcs",
-        "//pkg/util/uuid:all-srcs",
-        "//pkg/util/validation:all-srcs",
         "//pkg/util/version:all-srcs",
-        "//pkg/util/wait:all-srcs",
         "//pkg/util/workqueue/prometheus:all-srcs",
-        "//pkg/util/yaml:all-srcs",
     ],
     tags = ["automanaged"],
 )

vendor/k8s.io/kubernetes/pkg/util/exec/fake_exec.go

@@ -49,6 +49,9 @@ type FakeCmd struct {
 	CombinedOutputScript []FakeCombinedOutputAction
 	CombinedOutputCalls  int
 	CombinedOutputLog    [][]string
+	RunScript            []FakeRunAction
+	RunCalls             int
+	RunLog               [][]string
 	Dirs                 []string
 	Stdin                io.Reader
 	Stdout               io.Writer
@@ -61,6 +64,7 @@ func InitFakeCmd(fake *FakeCmd, cmd string, args ...string) Cmd {
 }
 
 type FakeCombinedOutputAction func() ([]byte, error)
+type FakeRunAction func() ([]byte, []byte, error)
 
 func (fake *FakeCmd) SetDir(dir string) {
 	fake.Dirs = append(fake.Dirs, dir)
@@ -79,7 +83,23 @@ func (fake *FakeCmd) SetStderr(out io.Writer) {
 }
 
 func (fake *FakeCmd) Run() error {
-	return fmt.Errorf("unimplemented")
+	if fake.RunCalls > len(fake.RunScript)-1 {
+		panic("ran out of Run() actions")
+	}
+	if fake.RunLog == nil {
+		fake.RunLog = [][]string{}
+	}
+	i := fake.RunCalls
+	fake.RunLog = append(fake.RunLog, append([]string{}, fake.Argv...))
+	fake.RunCalls++
+	stdout, stderr, err := fake.RunScript[i]()
+	if stdout != nil {
+		fake.Stdout.Write(stdout)
+	}
+	if stderr != nil {
+		fake.Stderr.Write(stderr)
+	}
+	return err
 }
 
 func (fake *FakeCmd) CombinedOutput() ([]byte, error) {

vendor/k8s.io/kubernetes/pkg/util/io/BUILD

@@ -5,37 +5,13 @@ licenses(["notice"])
 load(
     "@io_bazel_rules_go//go:def.bzl",
     "go_library",
-    "go_test",
 )
 
 go_library(
     name = "go_default_library",
-    srcs = [
-        "io.go",
-        "writer.go",
-    ],
+    srcs = ["writer.go"],
     tags = ["automanaged"],
-    deps = [
-        "//pkg/api:go_default_library",
-        "//pkg/api/v1:go_default_library",
-        "//vendor/github.com/golang/glog:go_default_library",
-        "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
-    ],
-)
-
-go_test(
-    name = "go_default_xtest",
-    srcs = ["io_test.go"],
-    tags = ["automanaged"],
-    deps = [
-        "//pkg/api:go_default_library",
-        "//pkg/util/io:go_default_library",
-        "//pkg/volume:go_default_library",
-        "//vendor/github.com/pborman/uuid:go_default_library",
-        "//vendor/k8s.io/apimachinery/pkg/api/equality:go_default_library",
-        "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
-        "//vendor/k8s.io/client-go/util/testing:go_default_library",
-    ],
+    deps = ["//vendor/github.com/golang/glog:go_default_library"],
 )
 
 filegroup(

vendor/k8s.io/kubernetes/pkg/util/io/io.go

@@ -1,61 +0,0 @@
-/*
-Copyright 2015 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package io
-
-import (
-	"fmt"
-	"io/ioutil"
-	"os"
-
-	"k8s.io/apimachinery/pkg/runtime"
-	"k8s.io/kubernetes/pkg/api"
-	"k8s.io/kubernetes/pkg/api/v1"
-)
-
-// LoadPodFromFile will read, decode, and return a Pod from a file.
-func LoadPodFromFile(filePath string) (*v1.Pod, error) {
-	if filePath == "" {
-		return nil, fmt.Errorf("file path not specified")
-	}
-	podDef, err := ioutil.ReadFile(filePath)
-	if err != nil {
-		return nil, fmt.Errorf("failed to read file path %s: %+v", filePath, err)
-	}
-	if len(podDef) == 0 {
-		return nil, fmt.Errorf("file was empty: %s", filePath)
-	}
-	pod := &v1.Pod{}
-
-	codec := api.Codecs.LegacyCodec(api.Registry.GroupOrDie(v1.GroupName).GroupVersion)
-	if err := runtime.DecodeInto(codec, podDef, pod); err != nil {
-		return nil, fmt.Errorf("failed decoding file: %v", err)
-	}
-	return pod, nil
-}
-
-// SavePodToFile will encode and save a pod to a given path & permissions
-func SavePodToFile(pod *v1.Pod, filePath string, perm os.FileMode) error {
-	if filePath == "" {
-		return fmt.Errorf("file path not specified")
-	}
-	codec := api.Codecs.LegacyCodec(api.Registry.GroupOrDie(v1.GroupName).GroupVersion)
-	data, err := runtime.Encode(codec, pod)
-	if err != nil {
-		return fmt.Errorf("failed encoding pod: %v", err)
-	}
-	return ioutil.WriteFile(filePath, data, perm)
-}

vendor/k8s.io/kubernetes/pkg/util/io/writer.go

@@ -28,6 +28,7 @@ import (
 
 // Writer is an interface which allows to write data to a file.
 type Writer interface {
+	// WriteFile mimics ioutil.WriteFile.
 	WriteFile(filename string, data []byte, perm os.FileMode) error
 }
 
@@ -36,31 +37,32 @@ type Writer interface {
 type StdWriter struct {
 }
 
+// WriteFile directly calls ioutil.WriteFile.
 func (writer *StdWriter) WriteFile(filename string, data []byte, perm os.FileMode) error {
 	return ioutil.WriteFile(filename, data, perm)
 }
 
-// Alternative implementation of Writer interface that allows writing data to file
-// using nsenter command.
+// NsenterWriter is implementation of Writer interface that allows writing data
+// to file using nsenter command.
 // If a program (e.g. kubelet) runs in a container it may want to write data to
 // a mounted device. Since in Docker, mount propagation mode is set to private,
 // it will not see the mounted device in its own namespace. To work around this
-// limitaion one has to first enter hosts namespace (by using 'nsenter') and only
-// then write data.
-type NsenterWriter struct {
-}
+// limitation one has to first enter hosts namespace (by using 'nsenter') and
+// only then write data.
+type NsenterWriter struct{}
 
-// TODO: should take a writer, not []byte
+// WriteFile calls 'nsenter cat - > <the file>' and 'nsenter chmod' to create a
+// file on the host.
 func (writer *NsenterWriter) WriteFile(filename string, data []byte, perm os.FileMode) error {
 	cmd := "nsenter"
-	base_args := []string{
+	baseArgs := []string{
 		"--mount=/rootfs/proc/1/ns/mnt",
 		"--",
 	}
 
-	echo_args := append(base_args, "sh", "-c", fmt.Sprintf("cat > %s", filename))
-	glog.V(5).Infof("Command to write data to file: %v %v", cmd, echo_args)
-	command := exec.Command(cmd, echo_args...)
+	echoArgs := append(baseArgs, "sh", "-c", fmt.Sprintf("cat > %s", filename))
+	glog.V(5).Infof("Command to write data to file: %v %v", cmd, echoArgs)
+	command := exec.Command(cmd, echoArgs...)
 	command.Stdin = bytes.NewBuffer(data)
 	outputBytes, err := command.CombinedOutput()
 	if err != nil {
@@ -68,9 +70,9 @@ func (writer *NsenterWriter) WriteFile(filename string, data []byte, perm os.Fil
 		return err
 	}
 
-	chmod_args := append(base_args, "chmod", fmt.Sprintf("%o", perm), filename)
-	glog.V(5).Infof("Command to change permissions to file: %v %v", cmd, chmod_args)
-	outputBytes, err = exec.Command(cmd, chmod_args...).CombinedOutput()
+	chmodArgs := append(baseArgs, "chmod", fmt.Sprintf("%o", perm), filename)
+	glog.V(5).Infof("Command to change permissions to file: %v %v", cmd, chmodArgs)
+	outputBytes, err = exec.Command(cmd, chmodArgs...).CombinedOutput()
 	if err != nil {
 		glog.Errorf("Output from chmod command: %v", string(outputBytes))
 		return err

vendor/k8s.io/kubernetes/pkg/util/mount/fake.go

@@ -124,6 +124,14 @@ func (f *FakeMounter) List() ([]MountPoint, error) {
 	return f.MountPoints, nil
 }
 
+func (f *FakeMounter) IsMountPointMatch(mp MountPoint, dir string) bool {
+	return (mp.Path == dir)
+}
+
+func (f *FakeMounter) IsNotMountPoint(dir string) (bool, error) {
+	return IsNotMountPoint(f, dir)
+}
+
 func (f *FakeMounter) IsLikelyNotMountPoint(file string) (bool, error) {
 	f.mutex.Lock()
 	defer f.mutex.Unlock()

vendor/k8s.io/kubernetes/pkg/util/mount/mount.go

@@ -44,8 +44,21 @@ type Interface interface {
 	// it could change between chunked reads). This is guaranteed to be
 	// consistent.
 	List() ([]MountPoint, error)
-	// IsLikelyNotMountPoint determines if a directory is a mountpoint.
+	// IsMountPointMatch determines if the mountpoint matches the dir
+	IsMountPointMatch(mp MountPoint, dir string) bool
+	// IsNotMountPoint determines if a directory is a mountpoint.
 	// It should return ErrNotExist when the directory does not exist.
+	// IsNotMountPoint is more expensive than IsLikelyNotMountPoint.
+	// IsNotMountPoint detects bind mounts in linux.
+	// IsNotMountPoint enumerates all the mountpoints using List() and
+	// the list of mountpoints may be large, then it uses
+	// IsMountPointMatch to evaluate whether the directory is a mountpoint
+	IsNotMountPoint(file string) (bool, error)
+	// IsLikelyNotMountPoint uses heuristics to determine if a directory
+	// is a mountpoint.
+	// It should return ErrNotExist when the directory does not exist.
+	// IsLikelyNotMountPoint does NOT properly detect all mountpoint types
+	// most notably linux bind mounts.
 	IsLikelyNotMountPoint(file string) (bool, error)
 	// DeviceOpened determines if the device is in use elsewhere
 	// on the system, i.e. still mounted.
@@ -199,3 +212,34 @@ func getDeviceNameFromMount(mounter Interface, mountPath, pluginDir string) (str
 
 	return path.Base(mountPath), nil
 }
+
+// IsNotMountPoint determines if a directory is a mountpoint.
+// It should return ErrNotExist when the directory does not exist.
+// This method uses the List() of all mountpoints
+// It is more extensive than IsLikelyNotMountPoint
+// and it detects bind mounts in linux
+func IsNotMountPoint(mounter Interface, file string) (bool, error) {
+	// IsLikelyNotMountPoint provides a quick check
+	// to determine whether file IS A mountpoint
+	notMnt, notMntErr := mounter.IsLikelyNotMountPoint(file)
+	if notMntErr != nil {
+		return notMnt, notMntErr
+	}
+	// identified as mountpoint, so return this fact
+	if notMnt == false {
+		return notMnt, nil
+	}
+	// check all mountpoints since IsLikelyNotMountPoint
+	// is not reliable for some mountpoint types
+	mountPoints, mountPointsErr := mounter.List()
+	if mountPointsErr != nil {
+		return notMnt, mountPointsErr
+	}
+	for _, mp := range mountPoints {
+		if mounter.IsMountPointMatch(mp, file) {
+			notMnt = false
+			break
+		}
+	}
+	return notMnt, nil
+}

vendor/k8s.io/kubernetes/pkg/util/mount/mount_linux.go

@@ -161,6 +161,15 @@ func (*Mounter) List() ([]MountPoint, error) {
 	return listProcMounts(procMountsPath)
 }
 
+func (mounter *Mounter) IsMountPointMatch(mp MountPoint, dir string) bool {
+	deletedDir := fmt.Sprintf("%s\\040(deleted)", dir)
+	return ((mp.Path == dir) || (mp.Path == deletedDir))
+}
+
+func (mounter *Mounter) IsNotMountPoint(dir string) (bool, error) {
+	return IsNotMountPoint(mounter, dir)
+}
+
 // IsLikelyNotMountPoint determines if a directory is not a mountpoint.
 // It is fast but not necessarily ALWAYS correct. If the path is in fact
 // a bind mount from one part of a mount to another it will not be detected.
@@ -168,10 +177,6 @@ func (*Mounter) List() ([]MountPoint, error) {
 // will return true. When in fact /tmp/b is a mount point. If this situation
 // if of interest to you, don't use this function...
 func (mounter *Mounter) IsLikelyNotMountPoint(file string) (bool, error) {
-	return IsNotMountPoint(file)
-}
-
-func IsNotMountPoint(file string) (bool, error) {
 	stat, err := os.Stat(file)
 	if err != nil {
 		return true, err

vendor/k8s.io/kubernetes/pkg/util/mount/mount_unsupported.go

@@ -34,6 +34,14 @@ func (mounter *Mounter) List() ([]MountPoint, error) {
 	return []MountPoint{}, nil
 }
 
+func (mounter *Mounter) IsMountPointMatch(mp MountPoint, dir string) bool {
+	return (mp.Path == dir)
+}
+
+func (mounter *Mounter) IsNotMountPoint(dir string) (bool, error) {
+	return IsNotMountPoint(mounter, dir)
+}
+
 func (mounter *Mounter) IsLikelyNotMountPoint(file string) (bool, error) {
 	return true, nil
 }
@@ -57,7 +65,3 @@ func (mounter *SafeFormatAndMount) formatAndMount(source string, target string,
 func (mounter *SafeFormatAndMount) diskLooksUnformatted(disk string) (bool, error) {
 	return true, nil
 }
-
-func IsNotMountPoint(file string) (bool, error) {
-	return true, nil
-}

vendor/k8s.io/kubernetes/pkg/util/mount/nsenter_mount.go

@@ -19,6 +19,7 @@ limitations under the License.
 package mount
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
@@ -162,6 +163,15 @@ func (*NsenterMounter) List() ([]MountPoint, error) {
 	return listProcMounts(hostProcMountsPath)
 }
 
+func (m *NsenterMounter) IsNotMountPoint(dir string) (bool, error) {
+	return IsNotMountPoint(m, dir)
+}
+
+func (*NsenterMounter) IsMountPointMatch(mp MountPoint, dir string) bool {
+	deletedDir := fmt.Sprintf("%s\\040(deleted)", dir)
+	return ((mp.Path == dir) || (mp.Path == deletedDir))
+}
+
 // IsLikelyNotMountPoint determines whether a path is a mountpoint by calling findmnt
 // in the host's root mount namespace.
 func (n *NsenterMounter) IsLikelyNotMountPoint(file string) (bool, error) {

vendor/k8s.io/kubernetes/pkg/util/mount/nsenter_mount_unsupported.go

@@ -38,6 +38,14 @@ func (*NsenterMounter) List() ([]MountPoint, error) {
 	return []MountPoint{}, nil
 }
 
+func (m *NsenterMounter) IsNotMountPoint(dir string) (bool, error) {
+	return IsNotMountPoint(m, dir)
+}
+
+func (*NsenterMounter) IsMountPointMatch(mp MountPoint, dir string) bool {
+	return (mp.Path == dir)
+}
+
 func (*NsenterMounter) IsLikelyNotMountPoint(file string) (bool, error) {
 	return true, nil
 }

vendor/k8s.io/kubernetes/pkg/util/net/sets/ipnet.go

@@ -21,8 +21,10 @@ import (
 	"strings"
 )
 
+// IPNet maps string to net.IPNet.
 type IPNet map[string]*net.IPNet
 
+// ParseIPNets parses string slice to IPNet.
 func ParseIPNets(specs ...string) (IPNet, error) {
 	ipnetset := make(IPNet)
 	for _, spec := range specs {
@@ -96,9 +98,9 @@ func (s IPNet) StringSlice() []string {
 }
 
 // IsSuperset returns true if and only if s1 is a superset of s2.
-func (s1 IPNet) IsSuperset(s2 IPNet) bool {
+func (s IPNet) IsSuperset(s2 IPNet) bool {
 	for k := range s2 {
-		_, found := s1[k]
+		_, found := s[k]
 		if !found {
 			return false
 		}
@@ -109,8 +111,8 @@ func (s1 IPNet) IsSuperset(s2 IPNet) bool {
 // Equal returns true if and only if s1 is equal (as a set) to s2.
 // Two sets are equal if their membership is identical.
 // (In practice, this means same elements, order doesn't matter)
-func (s1 IPNet) Equal(s2 IPNet) bool {
-	return len(s1) == len(s2) && s1.IsSuperset(s2)
+func (s IPNet) Equal(s2 IPNet) bool {
+	return len(s) == len(s2) && s.IsSuperset(s2)
 }
 
 // Len returns the size of the set.

vendor/k8s.io/kubernetes/pkg/util/sysctl/sysctl.go

@@ -29,12 +29,17 @@ const (
 	VmPanicOnOOM       = "vm/panic_on_oom"
 	KernelPanic        = "kernel/panic"
 	KernelPanicOnOops  = "kernel/panic_on_oops"
+	RootMaxKeys        = "kernel/keys/root_maxkeys"
+	RootMaxBytes       = "kernel/keys/root_maxbytes"
 
 	VmOvercommitMemoryAlways    = 1 // kernel performs no memory over-commit handling
 	VmPanicOnOOMInvokeOOMKiller = 0 // kernel calls the oom_killer function when OOM occurs
 
 	KernelPanicOnOopsAlways  = 1  // kernel panics on kernel oops
 	KernelPanicRebootTimeout = 10 // seconds after a panic for the kernel to reboot
+
+	RootMaxKeysSetting  = 1000000                 // Needed since docker creates a new key per container
+	RootMaxBytesSetting = RootMaxKeysSetting * 25 // allocate 25 bytes per key * number of MaxKeys
 )
 
 // An injectable interface for running sysctl commands.

vendor/k8s.io/kubernetes/pkg/util/umask_windows.go

@@ -1,27 +0,0 @@
-// +build windows
-
-/*
-Copyright 2014 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package util
-
-import (
-	"errors"
-)
-
-func Umask(mask int) (int, error) {
-	return 0, errors.New("platform and architecture is not supported")
-}

vendor/k8s.io/kubernetes/pkg/util/util.go

@@ -84,6 +84,15 @@ func FileExists(filename string) (bool, error) {
 	return true, nil
 }
 
+func FileOrSymlinkExists(filename string) (bool, error) {
+	if _, err := os.Lstat(filename); os.IsNotExist(err) {
+		return false, nil
+	} else if err != nil {
+		return false, err
+	}
+	return true, nil
+}
+
 // ReadDirNoStat returns a string of files/directories contained
 // in dirname without calling lstat on them.
 func ReadDirNoStat(dirname string) ([]string, error) {

vendor/k8s.io/kubernetes/pkg/util/version/BUILD

@@ -0,0 +1,38 @@
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])
+
+load(
+    "@io_bazel_rules_go//go:def.bzl",
+    "go_library",
+    "go_test",
+)
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "doc.go",
+        "version.go",
+    ],
+    tags = ["automanaged"],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["version_test.go"],
+    library = ":go_default_library",
+    tags = ["automanaged"],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+)

vendor/k8s.io/kubernetes/pkg/util/version/doc.go

@@ -1,7 +1,5 @@
-// +build !windows
-
 /*
-Copyright 2014 The Kubernetes Authors.
+Copyright 2016 The Kubernetes Authors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -16,12 +14,5 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package util
-
-import (
-	"syscall"
-)
-
-func Umask(mask int) (old int, err error) {
-	return syscall.Umask(mask), nil
-}
+// Package version provides utilities for version number comparisons
+package version

vendor/k8s.io/kubernetes/pkg/util/version/version.go

@@ -0,0 +1,236 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package version
+
+import (
+	"bytes"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// Version is an opqaue representation of a version number
+type Version struct {
+	components    []uint
+	semver        bool
+	preRelease    string
+	buildMetadata string
+}
+
+var (
+	// versionMatchRE splits a version string into numeric and "extra" parts
+	versionMatchRE = regexp.MustCompile(`^\s*v?([0-9]+(?:\.[0-9]+)*)(.*)*$`)
+	// extraMatchRE splits the "extra" part of versionMatchRE into semver pre-release and build metadata; it does not validate the "no leading zeroes" constraint for pre-release
+	extraMatchRE = regexp.MustCompile(`^(?:-([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?(?:\+([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?\s*$`)
+)
+
+func parse(str string, semver bool) (*Version, error) {
+	parts := versionMatchRE.FindStringSubmatch(str)
+	if parts == nil {
+		return nil, fmt.Errorf("could not parse %q as version", str)
+	}
+	numbers, extra := parts[1], parts[2]
+
+	components := strings.Split(numbers, ".")
+	if (semver && len(components) != 3) || (!semver && len(components) < 2) {
+		return nil, fmt.Errorf("illegal version string %q", str)
+	}
+
+	v := &Version{
+		components: make([]uint, len(components)),
+		semver:     semver,
+	}
+	for i, comp := range components {
+		if (i == 0 || semver) && strings.HasPrefix(comp, "0") && comp != "0" {
+			return nil, fmt.Errorf("illegal zero-prefixed version component %q in %q", comp, str)
+		}
+		num, err := strconv.ParseUint(comp, 10, 0)
+		if err != nil {
+			return nil, fmt.Errorf("illegal non-numeric version component %q in %q: %v", comp, str, err)
+		}
+		v.components[i] = uint(num)
+	}
+
+	if semver && extra != "" {
+		extraParts := extraMatchRE.FindStringSubmatch(extra)
+		if extraParts == nil {
+			return nil, fmt.Errorf("could not parse pre-release/metadata (%s) in version %q", extra, str)
+		}
+		v.preRelease, v.buildMetadata = extraParts[1], extraParts[2]
+
+		for _, comp := range strings.Split(v.preRelease, ".") {
+			if _, err := strconv.ParseUint(comp, 10, 0); err == nil {
+				if strings.HasPrefix(comp, "0") && comp != "0" {
+					return nil, fmt.Errorf("illegal zero-prefixed version component %q in %q", comp, str)
+				}
+			}
+		}
+	}
+
+	return v, nil
+}
+
+// ParseGeneric parses a "generic" version string. The version string must consist of two
+// or more dot-separated numeric fields (the first of which can't have leading zeroes),
+// followed by arbitrary uninterpreted data (which need not be separated from the final
+// numeric field by punctuation). For convenience, leading and trailing whitespace is
+// ignored, and the version can be preceded by the letter "v". See also ParseSemantic.
+func ParseGeneric(str string) (*Version, error) {
+	return parse(str, false)
+}
+
+// MustParseGeneric is like ParseGeneric except that it panics on error
+func MustParseGeneric(str string) *Version {
+	v, err := ParseGeneric(str)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+// ParseSemantic parses a version string that exactly obeys the syntax and semantics of
+// the "Semantic Versioning" specification (http://semver.org/) (although it ignores
+// leading and trailing whitespace, and allows the version to be preceded by "v"). For
+// version strings that are not guaranteed to obey the Semantic Versioning syntax, use
+// ParseGeneric.
+func ParseSemantic(str string) (*Version, error) {
+	return parse(str, true)
+}
+
+// MustParseSemantic is like ParseSemantic except that it panics on error
+func MustParseSemantic(str string) *Version {
+	v, err := ParseSemantic(str)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+// BuildMetadata returns the build metadata, if v is a Semantic Version, or ""
+func (v *Version) BuildMetadata() string {
+	return v.buildMetadata
+}
+
+// String converts a Version back to a string; note that for versions parsed with
+// ParseGeneric, this will not include the trailing uninterpreted portion of the version
+// number.
+func (v *Version) String() string {
+	var buffer bytes.Buffer
+
+	for i, comp := range v.components {
+		if i > 0 {
+			buffer.WriteString(".")
+		}
+		buffer.WriteString(fmt.Sprintf("%d", comp))
+	}
+	if v.preRelease != "" {
+		buffer.WriteString("-")
+		buffer.WriteString(v.preRelease)
+	}
+	if v.buildMetadata != "" {
+		buffer.WriteString("+")
+		buffer.WriteString(v.buildMetadata)
+	}
+
+	return buffer.String()
+}
+
+// compareInternal returns -1 if v is less than other, 1 if it is greater than other, or 0
+// if they are equal
+func (v *Version) compareInternal(other *Version) int {
+	for i := range v.components {
+		switch {
+		case i >= len(other.components):
+			if v.components[i] != 0 {
+				return 1
+			}
+		case other.components[i] < v.components[i]:
+			return 1
+		case other.components[i] > v.components[i]:
+			return -1
+		}
+	}
+
+	if !v.semver || !other.semver {
+		return 0
+	}
+
+	switch {
+	case v.preRelease == "" && other.preRelease != "":
+		return 1
+	case v.preRelease != "" && other.preRelease == "":
+		return -1
+	case v.preRelease == other.preRelease: // includes case where both are ""
+		return 0
+	}
+
+	vPR := strings.Split(v.preRelease, ".")
+	oPR := strings.Split(other.preRelease, ".")
+	for i := range vPR {
+		if i >= len(oPR) {
+			return 1
+		}
+		vNum, err := strconv.ParseUint(vPR[i], 10, 0)
+		if err == nil {
+			oNum, err := strconv.ParseUint(oPR[i], 10, 0)
+			if err == nil {
+				switch {
+				case oNum < vNum:
+					return 1
+				case oNum > vNum:
+					return -1
+				default:
+					continue
+				}
+			}
+		}
+		if oPR[i] < vPR[i] {
+			return 1
+		} else if oPR[i] > vPR[i] {
+			return -1
+		}
+	}
+
+	return 0
+}
+
+// AtLeast tests if a version is at least equal to a given minimum version. If both
+// Versions are Semantic Versions, this will use the Semantic Version comparison
+// algorithm. Otherwise, it will compare only the numeric components, with non-present
+// components being considered "0" (ie, "1.4" is equal to "1.4.0").
+func (v *Version) AtLeast(min *Version) bool {
+	return v.compareInternal(min) != -1
+}
+
+// LessThan tests if a version is less than a given version. (It is exactly the opposite
+// of AtLeast, for situations where asking "is v too old?" makes more sense than asking
+// "is v new enough?".)
+func (v *Version) LessThan(other *Version) bool {
+	return v.compareInternal(other) == -1
+}
+
+// Compare compares v against a version string (which will be parsed as either Semantic
+// or non-Semantic depending on v). On success it returns -1 if v is less than other, 1 if
+// it is greater than other, or 0 if they are equal.
+func (v *Version) Compare(other string) (int, error) {
+	ov, err := parse(other, v.semver)
+	if err != nil {
+		return 0, err
+	}
+	return v.compareInternal(ov), nil
+}