make progress bar POC for pause

than 10 seconds

packer/progressbar.go

@@ -5,7 +5,9 @@ package packer
 import (
 	"io"
 	"path/filepath"
+	"strings"
 	"sync"
+	"time"
 
 	pb "github.com/cheggaaa/pb"
 )
@@ -25,11 +27,66 @@ type UiProgressBar struct {
 
 func (p *UiProgressBar) TrackProgress(src string, currentSize, totalSize int64, stream io.ReadCloser) io.ReadCloser {
 	if p == nil {
+
 		return stream
 	}
 	p.lock.Lock()
 	defer p.lock.Unlock()
+	// custom prefix used to track configured waits rather than file downloads
+	// TODO: next time we feel we can justify a breaking interface change, this
+	// deserves its own method on the progress bar rather than this hacked
+	// workaround.
+	if strings.Contains(src, "-packerwaiter-") {
+		realPrefix := strings.Replace(src, "-packerwaiter-", "", -1)
+		return p.TrackProgressWait(realPrefix, currentSize, totalSize, stream)
+	}
+	return p.TrackProgressFile(src, currentSize, totalSize, stream)
 
+}
+
+func (p *UiProgressBar) TrackProgressWait(src string, currentSize, totalSize int64, stream io.ReadCloser) io.ReadCloser {
+	newPb := pb.New64(totalSize)
+	newPb.SetUnits(pb.U_DURATION)
+	newPb.ShowPercent = false
+	newPb.Prefix(src)
+
+	if p.pool == nil {
+
+		pool := pb.NewPool()
+		err := pool.Start()
+		if err != nil {
+			// here, we probably cannot lock
+			// stdout, so let's just return
+			// stream to avoid any error.
+			return stream
+		}
+		p.pool = pool
+	}
+	p.pool.Add(newPb)
+
+	p.pbs++
+	return &readCloser{
+		Reader: nil,
+		close: func() error {
+
+			for i := currentSize; i < totalSize; i++ {
+				newPb.Increment()
+				time.Sleep(time.Second)
+			}
+			newPb.Finish()
+			p.lock.Lock()
+			defer p.lock.Unlock()
+			p.pbs--
+			if p.pbs <= 0 {
+				p.pool.Stop()
+				p.pool = nil
+			}
+			return nil
+		},
+	}
+}
+
+func (p *UiProgressBar) TrackProgressFile(src string, currentSize, totalSize int64, stream io.ReadCloser) io.ReadCloser {
 	newPb := pb.New64(totalSize)
 	newPb.Set64(currentSize)
 	ProgressBarConfig(newPb, filepath.Base(src))

packer/provisioner.go

@@ -3,7 +3,9 @@ package packer
 import (
 	"context"
 	"fmt"
+	"io/ioutil"
 	"log"
+	"math"
 	"sync"
 	"time"
 
@@ -145,17 +147,33 @@ func (p *PausedProvisioner) Prepare(raws ...interface{}) error {
 
 func (p *PausedProvisioner) Provision(ctx context.Context, ui packersdk.Ui, comm packersdk.Communicator, generatedData map[string]interface{}) error {
 
-	// Use a select to determine if we get cancelled during the wait
 	ui.Say(fmt.Sprintf("Pausing %s before the next provisioner...", p.PauseBefore))
-	select {
-	case <-time.After(p.PauseBefore):
-	case <-ctx.Done():
-		return ctx.Err()
+	minimumTimeForPauseUpdate := float64(10)
+	if p.PauseBefore.Seconds() < minimumTimeForPauseUpdate {
+		// Use a select to determine if we get cancelled during the wait
+		select {
+		case <-time.After(p.PauseBefore):
+		case <-ctx.Done():
+			return ctx.Err()
+		}
+	} else {
+		err := p.updatesWhilePausing(ctx, ui)
+		if err != nil {
+			return err
+		}
 	}
 
 	return p.Provisioner.Provision(ctx, ui, comm, generatedData)
 }
 
+func (p *PausedProvisioner) updatesWhilePausing(ctx context.Context, ui packersdk.Ui) error {
+	TotalTime := int64(math.Round(p.PauseBefore.Seconds()))
+	ElapsedTime := int64(0)
+	pbCloser := ui.TrackProgress("-packerwaiter-Pausing...", ElapsedTime, TotalTime, ioutil.NopCloser(nil))
+	pbCloser.Close() // this is blocking
+	return nil
+}
+
 // RetriedProvisioner is a Provisioner implementation that retries
 // the provisioner whenever there's an error.
 type RetriedProvisioner struct {

packer/provisioner_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"math"
 	"testing"
 	"time"
 
@@ -129,11 +130,8 @@ func TestPausedProvisionerProvision(t *testing.T) {
 	}
 }
 
-func TestPausedProvisionerProvision_waits(t *testing.T) {
-	startTime := time.Now()
-	waitTime := 50 * time.Millisecond
-
-	prov := &PausedProvisioner{
+func pausedTestProvisionor(startTime time.Time, waitTime time.Duration) *PausedProvisioner {
+	return &PausedProvisioner{
 		PauseBefore: waitTime,
 		Provisioner: &packersdk.MockProvisioner{
 			ProvFunc: func(context.Context) error {
@@ -145,7 +143,13 @@ func TestPausedProvisionerProvision_waits(t *testing.T) {
 			},
 		},
 	}
+}
 
+func TestPausedProvisionerProvision_waits(t *testing.T) {
+	startTime := time.Now()
+	waitTime := 50 * time.Millisecond
+
+	prov := pausedTestProvisionor(startTime, waitTime)
 	err := prov.Provision(context.Background(), testUi(), new(packersdk.MockCommunicator), make(map[string]interface{}))
 
 	if err != nil {
@@ -153,6 +157,51 @@ func TestPausedProvisionerProvision_waits(t *testing.T) {
 	}
 }
 
+func TestPausedProvisionerProvision_waits_with_updates(t *testing.T) {
+	startTime := time.Now()
+	waitTime := 30 * time.Second
+
+	prov := pausedTestProvisionor(startTime, waitTime)
+	ui := new(packersdk.MockUi)
+	currentTime := time.Now()
+	err := prov.Provision(context.Background(), ui, new(packersdk.MockCommunicator), make(map[string]interface{}))
+
+	if err != nil {
+		t.Fatalf("prov failed: %v", err)
+	}
+
+	// TODO have to put check to get timestamp of when these messages were posted and verify that this is working as intended
+	expectedMessages := []string{
+		fmt.Sprintf("Pausing %s before the next provisioner...", waitTime),
+		"20 seconds left until the next provisioner",
+		"10 seconds left until the next provisioner",
+	}
+
+	if ui.SayMessages[0].Message != expectedMessages[0] {
+		t.Fatalf("expected: %s, got: %s", expectedMessages[0], ui.SayMessages[0].Message)
+	}
+
+	lastTime := currentTime
+	for index, message := range expectedMessages {
+		// Skiping first message as this has already been verified
+		if index == 0 {
+			continue
+		}
+
+		if ui.SayMessages[index].Message != message {
+			t.Fatalf("expected: %s, got: %s", message, ui.SayMessages[index].Message)
+		}
+
+		waitTimeBetweenMessages := math.Round(ui.SayMessages[index].SayTime.Sub(lastTime).Seconds())
+		if waitTimeBetweenMessages != 10 {
+			t.Fatalf("Did not wait the appropriate amount of time message: %v", ui.SayMessages[index].Message)
+		}
+
+		// setting last time to current SayTime
+		lastTime = ui.SayMessages[index].SayTime
+	}
+}
+
 func TestPausedProvisionerCancel(t *testing.T) {
 	topCtx, cancelTopCtx := context.WithCancel(context.Background())