From 8fb17f60d9fda35d9b460f928447c58110b55e08 Mon Sep 17 00:00:00 2001
From: Tejal Desai <tejaldesai@google.com>
Date: Thu, 30 Apr 2020 13:25:22 -0700
Subject: [PATCH] Defer initial snapshot. Remove ReadSuccess()

---
 pkg/commands/cache.go      |  6 ------
 pkg/commands/copy.go       |  2 --
 pkg/commands/run.go        |  1 -
 pkg/constants/constants.go |  2 +-
 pkg/executor/build.go      | 38 +++++++++++++++++++++-----------------
 pkg/snapshot/snapshot.go   |  1 +
 6 files changed, 23 insertions(+), 27 deletions(-)

diff --git a/pkg/commands/cache.go b/pkg/commands/cache.go
index 1d37e6251..63970734f 100644
--- a/pkg/commands/cache.go
+++ b/pkg/commands/cache.go
@@ -20,18 +20,12 @@ import v1 "github.com/google/go-containerregistry/pkg/v1"
 
 type Cached interface {
 	Layer() v1.Layer
-	ReadSuccess() bool
 }
 
 type caching struct {
 	layer       v1.Layer
-	readSuccess bool
 }
 
 func (c caching) Layer() v1.Layer {
 	return c.layer
 }
-
-func (c caching) ReadSuccess() bool {
-	return c.readSuccess
-}
diff --git a/pkg/commands/copy.go b/pkg/commands/copy.go
index e31efe2f3..472218fd6 100644
--- a/pkg/commands/copy.go
+++ b/pkg/commands/copy.go
@@ -189,8 +189,6 @@ func (cr *CachingCopyCommand) ExecuteCommand(config *v1.Config, buildArgs *docke
 	}
 
 	cr.layer = layers[0]
-	cr.readSuccess = true
-
 	cr.extractedFiles, err = util.GetFSFromLayers(kConfig.RootDir, layers, util.ExtractFunc(cr.extractFn), util.IncludeWhiteout())
 
 	logrus.Debugf("extractedFiles: %s", cr.extractedFiles)
diff --git a/pkg/commands/run.go b/pkg/commands/run.go
index 23b7f5fd7..d4a8003bf 100644
--- a/pkg/commands/run.go
+++ b/pkg/commands/run.go
@@ -200,7 +200,6 @@ func (cr *CachingRunCommand) ExecuteCommand(config *v1.Config, buildArgs *docker
 	}
 
 	cr.layer = layers[0]
-	cr.readSuccess = true
 
 	cr.extractedFiles, err = util.GetFSFromLayers(
 		kConfig.RootDir,
diff --git a/pkg/constants/constants.go b/pkg/constants/constants.go
index 19c46cef3..8dd5893ea 100644
--- a/pkg/constants/constants.go
+++ b/pkg/constants/constants.go
@@ -18,7 +18,7 @@ package constants
 
 const (
 	// RootDir is the path to the root directory
-	RootDir = "/root"
+	RootDir = "/"
 
 	// WorkspaceDir is the path to the workspace directory
 	WorkspaceDir = "/workspace"
diff --git a/pkg/executor/build.go b/pkg/executor/build.go
index 015466bf7..7090edc2f 100644
--- a/pkg/executor/build.go
+++ b/pkg/executor/build.go
@@ -317,13 +317,7 @@ func (s *stageBuilder) build() error {
 		return errors.Wrap(err, "failed to check filesystem whitelist")
 	}
 
-	// Take initial snapshot
-	t := timing.Start("Initial FS snapshot")
-	if err := s.snapshotter.Init(); err != nil {
-		return err
-	}
-
-	timing.DefaultRun.Stop(t)
+	initSnapshotTaken := false
 
 	cacheGroup := errgroup.Group{}
 	for index, command := range s.cmds {
@@ -346,6 +340,24 @@ func (s *stageBuilder) build() error {
 
 		logrus.Info(command.String())
 
+		isCacheCommand := func() bool {
+			switch command.(type) {
+			case commands.Cached:
+				return true
+			default:
+				return false
+			}
+		}
+		if !isCacheCommand() && !initSnapshotTaken {
+			// Take initial snapshot
+			t := timing.Start("Initial FS snapshot")
+			if err := s.snapshotter.Init(); err != nil {
+				return err
+			}
+			timing.DefaultRun.Stop(t)
+			initSnapshotTaken = true
+		}
+
 		if err := command.ExecuteCommand(&s.cf.Config, s.args); err != nil {
 			return errors.Wrap(err, "failed to execute command")
 		}
@@ -356,16 +368,7 @@ func (s *stageBuilder) build() error {
 			continue
 		}
 
-		fn := func() bool {
-			switch v := command.(type) {
-			case commands.Cached:
-				return v.ReadSuccess()
-			default:
-				return false
-			}
-		}
-
-		if fn() {
+		if isCacheCommand() {
 			v := command.(commands.Cached)
 			layer := v.Layer()
 			if err := s.saveLayerToImage(layer, command.String()); err != nil {
@@ -388,6 +391,7 @@ func (s *stageBuilder) build() error {
 			// Push layer to cache (in parallel) now along with new config file
 			if s.opts.Cache && command.ShouldCacheOutput() {
 				cacheGroup.Go(func() error {
+					logrus.Infof("%s is saved at %s", ck, tarPath)
 					return s.pushLayerToCache(s.opts, ck, tarPath, command.String())
 				})
 			}
diff --git a/pkg/snapshot/snapshot.go b/pkg/snapshot/snapshot.go
index 7b3df5661..d750601a4 100644
--- a/pkg/snapshot/snapshot.go
+++ b/pkg/snapshot/snapshot.go
@@ -51,6 +51,7 @@ func NewSnapshotter(l *LayeredMap, d string) *Snapshotter {
 
 // Init initializes a new snapshotter
 func (s *Snapshotter) Init() error {
+	logrus.Info("Taking initial snapshot")
 	_, _, err := s.scanFullFilesystem()
 	return err
 }