VMware vSphere Integrated Containers provider (#206)

* Add Virtual Kubelet provider for VIC

Initial virtual kubelet provider for VMware VIC.  This provider currently
handles creating and starting of a pod VM via the VIC portlayer and persona
server.  Image store handling via the VIC persona server.  This provider
currently requires the feature/wolfpack branch of VIC.

* Added pod stop and delete.  Also added node capacity.

Added the ability to stop and delete pod VMs via VIC.  Also retrieve
node capacity information from the VCH.

* Cleanup and readme file

Some file clean up and added a Readme.md markdown file for the VIC
provider.

* Cleaned up errors, added function comments, moved operation code

1. Cleaned up error handling.  Set standard for creating errors.
2. Added method prototype comments for all interface functions.
3. Moved PodCreator, PodStarter, PodStopper, and PodDeleter to a new folder.

* Add mocking code and unit tests for podcache, podcreator, and podstarter

Used the unit test framework used in VIC to handle assertions in the provider's
unit test.  Mocking code generated using OSS project mockery, which is compatible
with the testify assertion framework.

* Vendored packages for the VIC provider

Requires feature/wolfpack branch of VIC and a few specific commit sha of
projects used within VIC.

* Implementation of POD Stopper and Deleter unit tests (#4)

* Updated files for initial PR

vendor/github.com/vmware/govmomi/vim25/progress/aggregator.go

@@ -0,0 +1,73 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+import "sync"
+
+type Aggregator struct {
+	downstream Sinker
+	upstream   chan (<-chan Report)
+
+	done chan struct{}
+	w    sync.WaitGroup
+}
+
+func NewAggregator(s Sinker) *Aggregator {
+	a := &Aggregator{
+		downstream: s,
+		upstream:   make(chan (<-chan Report)),
+
+		done: make(chan struct{}),
+	}
+
+	a.w.Add(1)
+	go a.loop()
+
+	return a
+}
+
+func (a *Aggregator) loop() {
+	defer a.w.Done()
+
+	dch := a.downstream.Sink()
+	defer close(dch)
+
+	for {
+		select {
+		case uch := <-a.upstream:
+			// Drain upstream channel
+			for e := range uch {
+				dch <- e
+			}
+		case <-a.done:
+			return
+		}
+	}
+}
+
+func (a *Aggregator) Sink() chan<- Report {
+	ch := make(chan Report)
+	a.upstream <- ch
+	return ch
+}
+
+// Done marks the aggregator as done. No more calls to Sink() may be made and
+// the downstream progress report channel will be closed when Done() returns.
+func (a *Aggregator) Done() {
+	close(a.done)
+	a.w.Wait()
+}

vendor/github.com/vmware/govmomi/vim25/progress/aggregator_test.go

@@ -0,0 +1,81 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+import (
+	"testing"
+	"time"
+)
+
+func TestAggregatorNoSinks(t *testing.T) {
+	ch := make(chan Report)
+	a := NewAggregator(dummySinker{ch})
+	a.Done()
+
+	_, ok := <-ch
+	if ok {
+		t.Errorf("Expected channel to be closed")
+	}
+}
+
+func TestAggregatorMultipleSinks(t *testing.T) {
+	ch := make(chan Report)
+	a := NewAggregator(dummySinker{ch})
+
+	for i := 0; i < 5; i++ {
+		go func(ch chan<- Report) {
+			ch <- dummyReport{}
+			ch <- dummyReport{}
+			close(ch)
+		}(a.Sink())
+
+		<-ch
+		<-ch
+	}
+
+	a.Done()
+
+	_, ok := <-ch
+	if ok {
+		t.Errorf("Expected channel to be closed")
+	}
+}
+
+func TestAggregatorSinkInFlightOnDone(t *testing.T) {
+	ch := make(chan Report)
+	a := NewAggregator(dummySinker{ch})
+
+	// Simulate upstream
+	go func(ch chan<- Report) {
+		time.Sleep(1 * time.Millisecond)
+		ch <- dummyReport{}
+		close(ch)
+	}(a.Sink())
+
+	// Drain downstream
+	go func(ch <-chan Report) {
+		<-ch
+	}(ch)
+
+	// This should wait for upstream to complete
+	a.Done()
+
+	_, ok := <-ch
+	if ok {
+		t.Errorf("Expected channel to be closed")
+	}
+}

vendor/github.com/vmware/govmomi/vim25/progress/common_test.go

@@ -0,0 +1,43 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+type dummySinker struct {
+	ch chan Report
+}
+
+func (d dummySinker) Sink() chan<- Report {
+	return d.ch
+}
+
+type dummyReport struct {
+	p float32
+	d string
+	e error
+}
+
+func (p dummyReport) Percentage() float32 {
+	return p.p
+}
+
+func (p dummyReport) Detail() string {
+	return p.d
+}
+
+func (p dummyReport) Error() error {
+	return p.e
+}

vendor/github.com/vmware/govmomi/vim25/progress/doc.go

@@ -0,0 +1,32 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+/*
+The progress package contains functionality to deal with progress reporting.
+The functionality is built to serve progress reporting for infrastructure
+operations when talking the vSphere API, but is generic enough to be used
+elsewhere.
+
+At the core of this progress reporting API lies the Sinker interface. This
+interface is implemented by any object that can act as a sink for progress
+reports. Callers of the Sink() function receives a send-only channel for
+progress reports. They are responsible for closing the channel when done.
+This semantic makes it easy to keep track of multiple progress report channels;
+they are only created when Sink() is called and assumed closed when any
+function that receives a Sinker parameter returns.
+*/

vendor/github.com/vmware/govmomi/vim25/progress/prefix.go

@@ -0,0 +1,54 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+import "fmt"
+
+type prefixedReport struct {
+	Report
+	prefix string
+}
+
+func (r prefixedReport) Detail() string {
+	if d := r.Report.Detail(); d != "" {
+		return fmt.Sprintf("%s: %s", r.prefix, d)
+	}
+
+	return r.prefix
+}
+
+func prefixLoop(upstream <-chan Report, downstream chan<- Report, prefix string) {
+	defer close(downstream)
+
+	for r := range upstream {
+		downstream <- prefixedReport{
+			Report: r,
+			prefix: prefix,
+		}
+	}
+}
+
+func Prefix(s Sinker, prefix string) Sinker {
+	fn := func() chan<- Report {
+		upstream := make(chan Report)
+		downstream := s.Sink()
+		go prefixLoop(upstream, downstream, prefix)
+		return upstream
+	}
+
+	return SinkFunc(fn)
+}

vendor/github.com/vmware/govmomi/vim25/progress/prefix_test.go

@@ -0,0 +1,40 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+import "testing"
+
+func TestPrefix(t *testing.T) {
+	var r Report
+
+	ch := make(chan Report, 1)
+	s := Prefix(dummySinker{ch}, "prefix").Sink()
+
+	// No detail
+	s <- dummyReport{d: ""}
+	r = <-ch
+	if r.Detail() != "prefix" {
+		t.Errorf("Expected detail to be prefixed")
+	}
+
+	// With detail
+	s <- dummyReport{d: "something"}
+	r = <-ch
+	if r.Detail() != "prefix: something" {
+		t.Errorf("Expected detail to be prefixed")
+	}
+}

vendor/github.com/vmware/govmomi/vim25/progress/reader.go

@@ -0,0 +1,185 @@
+/*
+Copyright (c) 2014-2015 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+import (
+	"container/list"
+	"context"
+	"fmt"
+	"io"
+	"sync/atomic"
+	"time"
+)
+
+type readerReport struct {
+	t time.Time
+
+	pos  int64
+	size int64
+	bps  *uint64
+
+	err error
+}
+
+func (r readerReport) Percentage() float32 {
+	return 100.0 * float32(r.pos) / float32(r.size)
+}
+
+func (r readerReport) Detail() string {
+	const (
+		KiB = 1024
+		MiB = 1024 * KiB
+		GiB = 1024 * MiB
+	)
+
+	// Use the reader's bps field, so this report returns an up-to-date number.
+	//
+	// For example: if there hasn't been progress for the last 5 seconds, the
+	// most recent report should return "0B/s".
+	//
+	bps := atomic.LoadUint64(r.bps)
+
+	switch {
+	case bps >= GiB:
+		return fmt.Sprintf("%.1fGiB/s", float32(bps)/float32(GiB))
+	case bps >= MiB:
+		return fmt.Sprintf("%.1fMiB/s", float32(bps)/float32(MiB))
+	case bps >= KiB:
+		return fmt.Sprintf("%.1fKiB/s", float32(bps)/float32(KiB))
+	default:
+		return fmt.Sprintf("%dB/s", bps)
+	}
+}
+
+func (p readerReport) Error() error {
+	return p.err
+}
+
+// reader wraps an io.Reader and sends a progress report over a channel for
+// every read it handles.
+type reader struct {
+	r io.Reader
+
+	pos  int64
+	size int64
+	bps  uint64
+
+	ch  chan<- Report
+	ctx context.Context
+}
+
+func NewReader(ctx context.Context, s Sinker, r io.Reader, size int64) *reader {
+	pr := reader{
+		r:    r,
+		ctx:  ctx,
+		size: size,
+	}
+
+	// Reports must be sent downstream and to the bps computation loop.
+	pr.ch = Tee(s, newBpsLoop(&pr.bps)).Sink()
+
+	return &pr
+}
+
+// Read calls the Read function on the underlying io.Reader. Additionally,
+// every read causes a progress report to be sent to the progress reader's
+// underlying channel.
+func (r *reader) Read(b []byte) (int, error) {
+	n, err := r.r.Read(b)
+	r.pos += int64(n)
+
+	if err != nil && err != io.EOF {
+		return n, err
+	}
+
+	q := readerReport{
+		t:    time.Now(),
+		pos:  r.pos,
+		size: r.size,
+		bps:  &r.bps,
+	}
+
+	select {
+	case r.ch <- q:
+	case <-r.ctx.Done():
+	}
+
+	return n, err
+}
+
+// Done marks the progress reader as done, optionally including an error in the
+// progress report. After sending it, the underlying channel is closed.
+func (r *reader) Done(err error) {
+	q := readerReport{
+		t:    time.Now(),
+		pos:  r.pos,
+		size: r.size,
+		bps:  &r.bps,
+		err:  err,
+	}
+
+	select {
+	case r.ch <- q:
+		close(r.ch)
+	case <-r.ctx.Done():
+	}
+}
+
+// newBpsLoop returns a sink that monitors and stores throughput.
+func newBpsLoop(dst *uint64) SinkFunc {
+	fn := func() chan<- Report {
+		sink := make(chan Report)
+		go bpsLoop(sink, dst)
+		return sink
+	}
+
+	return fn
+}
+
+func bpsLoop(ch <-chan Report, dst *uint64) {
+	l := list.New()
+
+	for {
+		var tch <-chan time.Time
+
+		// Setup timer for front of list to become stale.
+		if e := l.Front(); e != nil {
+			dt := time.Second - time.Now().Sub(e.Value.(readerReport).t)
+			tch = time.After(dt)
+		}
+
+		select {
+		case q, ok := <-ch:
+			if !ok {
+				return
+			}
+
+			l.PushBack(q)
+		case <-tch:
+			l.Remove(l.Front())
+		}
+
+		// Compute new bps
+		if l.Len() == 0 {
+			atomic.StoreUint64(dst, 0)
+		} else {
+			f := l.Front().Value.(readerReport)
+			b := l.Back().Value.(readerReport)
+			atomic.StoreUint64(dst, uint64(b.pos-f.pos))
+		}
+	}
+}

vendor/github.com/vmware/govmomi/vim25/progress/reader_test.go

@@ -0,0 +1,92 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+import (
+	"context"
+	"io"
+	"strings"
+	"testing"
+)
+
+func TestReader(t *testing.T) {
+	s := "helloworld"
+	ch := make(chan Report, 1)
+	pr := NewReader(context.Background(), &dummySinker{ch}, strings.NewReader(s), int64(len(s)))
+
+	var buf [10]byte
+	var q Report
+	var n int
+	var err error
+
+	// Read first byte
+	n, err = pr.Read(buf[0:1])
+	if n != 1 {
+		t.Errorf("Expected n=1, but got: %d", n)
+	}
+
+	if err != nil {
+		t.Errorf("Error: %s", err)
+	}
+
+	q = <-ch
+	if q.Error() != nil {
+		t.Errorf("Error: %s", err)
+	}
+
+	if f := q.Percentage(); f != 10.0 {
+		t.Errorf("Expected percentage after 1 byte to be 10%%, but got: %.0f%%", f)
+	}
+
+	// Read remaining bytes
+	n, err = pr.Read(buf[:])
+	if n != 9 {
+		t.Errorf("Expected n=1, but got: %d", n)
+	}
+	if err != nil {
+		t.Errorf("Error: %s", err)
+	}
+
+	q = <-ch
+	if q.Error() != nil {
+		t.Errorf("Error: %s", err)
+	}
+
+	if f := q.Percentage(); f != 100.0 {
+		t.Errorf("Expected percentage after 10 bytes to be 100%%, but got: %.0f%%", f)
+	}
+
+	// Read EOF
+	_, err = pr.Read(buf[:])
+	q = <-ch
+	if err != io.EOF {
+		t.Errorf("Expected io.EOF, but got: %s", err)
+	}
+
+	// Mark progress reader as done
+	pr.Done(io.EOF)
+	q = <-ch
+	if err != io.EOF {
+		t.Errorf("Expected io.EOF, but got: %s", err)
+	}
+
+	// Progress channel should be closed after progress reader is marked done
+	_, ok := <-ch
+	if ok {
+		t.Errorf("Expected channel to be closed")
+	}
+}

vendor/github.com/vmware/govmomi/vim25/progress/report.go

@@ -0,0 +1,26 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+// Report defines the interface for types that can deliver progress reports.
+// Examples include uploads/downloads in the http client and the task info
+// field in the task managed object.
+type Report interface {
+	Percentage() float32
+	Detail() string
+	Error() error
+}

vendor/github.com/vmware/govmomi/vim25/progress/scale.go

@@ -0,0 +1,76 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+type scaledReport struct {
+	Report
+	n int
+	i int
+}
+
+func (r scaledReport) Percentage() float32 {
+	b := 100 * float32(r.i) / float32(r.n)
+	return b + (r.Report.Percentage() / float32(r.n))
+}
+
+type scaleOne struct {
+	s Sinker
+	n int
+	i int
+}
+
+func (s scaleOne) Sink() chan<- Report {
+	upstream := make(chan Report)
+	downstream := s.s.Sink()
+	go s.loop(upstream, downstream)
+	return upstream
+}
+
+func (s scaleOne) loop(upstream <-chan Report, downstream chan<- Report) {
+	defer close(downstream)
+
+	for r := range upstream {
+		downstream <- scaledReport{
+			Report: r,
+			n:      s.n,
+			i:      s.i,
+		}
+	}
+}
+
+type scaleMany struct {
+	s Sinker
+	n int
+	i int
+}
+
+func Scale(s Sinker, n int) Sinker {
+	return &scaleMany{
+		s: s,
+		n: n,
+	}
+}
+
+func (s *scaleMany) Sink() chan<- Report {
+	if s.i == s.n {
+		s.n++
+	}
+
+	ch := scaleOne{s: s.s, n: s.n, i: s.i}.Sink()
+	s.i++
+	return ch
+}

vendor/github.com/vmware/govmomi/vim25/progress/scale_test.go

@@ -0,0 +1,45 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+import "testing"
+
+func TestScaleMany(t *testing.T) {
+	ch := make(chan Report)
+	a := NewAggregator(dummySinker{ch})
+	defer a.Done()
+
+	s := Scale(a, 5)
+
+	go func() {
+		for i := 0; i < 5; i++ {
+			go func(ch chan<- Report) {
+				ch <- dummyReport{p: 0.0}
+				ch <- dummyReport{p: 50.0}
+				close(ch)
+			}(s.Sink())
+		}
+	}()
+
+	// Expect percentages to be scaled across sinks
+	for p := float32(0.0); p < 100.0; p += 10.0 {
+		r := <-ch
+		if r.Percentage() != p {
+			t.Errorf("Expected percentage to be: %.0f%%", p)
+		}
+	}
+}

vendor/github.com/vmware/govmomi/vim25/progress/sinker.go

@@ -0,0 +1,33 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+// Sinker defines what is expected of a type that can act as a sink for
+// progress reports. The semantics are as follows. If you call Sink(), you are
+// responsible for closing the returned channel. Closing this channel means
+// that the related task is done, or resulted in error.
+type Sinker interface {
+	Sink() chan<- Report
+}
+
+// SinkFunc defines a function that returns a progress report channel.
+type SinkFunc func() chan<- Report
+
+// Sink makes the SinkFunc implement the Sinker interface.
+func (fn SinkFunc) Sink() chan<- Report {
+	return fn()
+}

vendor/github.com/vmware/govmomi/vim25/progress/tee.go

@@ -0,0 +1,41 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+// Tee works like Unix tee; it forwards all progress reports it receives to the
+// specified sinks
+func Tee(s1, s2 Sinker) Sinker {
+	fn := func() chan<- Report {
+		d1 := s1.Sink()
+		d2 := s2.Sink()
+		u := make(chan Report)
+		go tee(u, d1, d2)
+		return u
+	}
+
+	return SinkFunc(fn)
+}
+
+func tee(u <-chan Report, d1, d2 chan<- Report) {
+	defer close(d1)
+	defer close(d2)
+
+	for r := range u {
+		d1 <- r
+		d2 <- r
+	}
+}

vendor/github.com/vmware/govmomi/vim25/progress/tee_test.go

@@ -0,0 +1,46 @@
+/*
+Copyright (c) 2014 VMware, Inc. All Rights Reserved.
+
+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 progress
+
+import "testing"
+
+func TestTee(t *testing.T) {
+	var ok bool
+
+	ch1 := make(chan Report)
+	ch2 := make(chan Report)
+
+	s := Tee(&dummySinker{ch: ch1}, &dummySinker{ch: ch2})
+
+	in := s.Sink()
+	in <- dummyReport{}
+	close(in)
+
+	// Receive dummy on both sinks
+	<-ch1
+	<-ch2
+
+	_, ok = <-ch1
+	if ok {
+		t.Errorf("Expected channel to be closed")
+	}
+
+	_, ok = <-ch2
+	if ok {
+		t.Errorf("Expected channel to be closed")
+	}
+}