wip: skip-layers for analyzer

Signed-off-by: Javier Romero <jromero@pivotal.io>
buildpacks · Jun 27, 2019 · fa7d238 · fa7d238
1 parent af83d98
commit fa7d238
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Showing 4 changed files with 84 additions and 43 deletions.
diff --git a/analyzer.go b/analyzer.go
@@ -11,14 +11,14 @@ import (
 )
 
 type Analyzer struct {
-	Buildpacks   []*Buildpack
-	AppDir       string
 	AnalyzedPath string
-	LayersDir    string
+	AppDir       string
+	Buildpacks   []*Buildpack
+	GID, UID     int
 	In           []byte
+	LayersDir    string
 	Out, Err     *log.Logger
-	UID          int
-	GID          int
+	SkipLayers   bool
 }
 
 func (a *Analyzer) Analyze(image imgutil.Image) error {
@@ -27,51 +27,55 @@ func (a *Analyzer) Analyze(image imgutil.Image) error {
 		return err
 	}
 
-	for _, buildpack := range a.Buildpacks {
-		cache, err := readBuildpackLayersDir(a.LayersDir, *buildpack)
-		if err != nil {
-			return err
-		}
+	if !a.SkipLayers {
+		for _, buildpack := range a.Buildpacks {
+			bpLayersDir, err := readBuildpackLayersDir(a.LayersDir, *buildpack)
+			if err != nil {
+				return err
+			}
 
-		metadataLayers := data.MetadataForBuildpack(buildpack.ID).Layers
-		for _, cachedLayer := range cache.layers {
-			cacheType := cachedLayer.classifyCache(metadataLayers)
-			switch cacheType {
-			case cacheStaleNoMetadata:
-				a.Out.Printf("removing stale cached launch layer '%s', not in metadata \n", cachedLayer.Identifier())
-				if err := cachedLayer.remove(); err != nil {
-					return err
-				}
-			case cacheStaleWrongSHA:
-				a.Out.Printf("removing stale cached launch layer '%s'", cachedLayer.Identifier())
-				if err := cachedLayer.remove(); err != nil {
-					return err
-				}
-			case cacheMalformed:
-				a.Out.Printf("removing malformed cached layer '%s'", cachedLayer.Identifier())
-				if err := cachedLayer.remove(); err != nil {
-					return err
-				}
-			case cacheNotForLaunch:
-				a.Out.Printf("using cached layer '%s'", cachedLayer.Identifier())
-			case cacheValid:
-				a.Out.Printf("using cached launch layer '%s'", cachedLayer.Identifier())
-				a.Out.Printf("rewriting metadata for layer '%s'", cachedLayer.Identifier())
-				if err := cachedLayer.writeMetadata(metadataLayers); err != nil {
-					return err
+			metadataLayers := data.MetadataForBuildpack(buildpack.ID).Layers
+			for _, cachedLayer := range bpLayersDir.layers {
+				cacheType := cachedLayer.classifyCache(metadataLayers)
+				switch cacheType {
+				case cacheStaleNoMetadata:
+					a.Out.Printf("removing stale cached launch layer '%s', not in metadata \n", cachedLayer.Identifier())
+					if err := cachedLayer.remove(); err != nil {
+						return err
+					}
+				case cacheStaleWrongSHA:
+					a.Out.Printf("removing stale cached launch layer '%s'", cachedLayer.Identifier())
+					if err := cachedLayer.remove(); err != nil {
+						return err
+					}
+				case cacheMalformed:
+					a.Out.Printf("removing malformed cached layer '%s'", cachedLayer.Identifier())
+					if err := cachedLayer.remove(); err != nil {
+						return err
+					}
+				case cacheNotForLaunch:
+					a.Out.Printf("using cached layer '%s'", cachedLayer.Identifier())
+				case cacheValid:
+					a.Out.Printf("using cached launch layer '%s'", cachedLayer.Identifier())
+					a.Out.Printf("rewriting metadata for layer '%s'", cachedLayer.Identifier())
+					if err := cachedLayer.writeMetadata(metadataLayers); err != nil {
+						return err
+					}
 				}
 			}
-		}
 
-		for lmd, data := range metadataLayers {
-			if !data.Build && !data.Cache {
-				layer := cache.newBPLayer(lmd)
-				a.Out.Printf("writing metadata for uncached layer '%s'", layer.Identifier())
-				if err := layer.writeMetadata(metadataLayers); err != nil {
-					return err
+			for lmd, data := range metadataLayers {
+				if !data.Build && !data.Cache {
+					layer := bpLayersDir.newBPLayer(lmd)
+					a.Out.Printf("writing metadata for uncached layer '%s'", layer.Identifier())
+					if err := layer.writeMetadata(metadataLayers); err != nil {
+						return err
+					}
 				}
 			}
 		}
+	} else {
+		a.Out.Printf("Skipping buildpack layer analysis")
 	}
 
 	// if analyzer is running as root it needs to fix the ownership of the layers dir

diff --git a/analyzer_test.go b/analyzer_test.go
@@ -494,6 +494,35 @@ func testAnalyzer(t *testing.T, when spec.G, it spec.S) {
 						h.AssertContains(t, entries, `[metadata]`)
 					})
 				})
+
+				when("skip-layers is true", func() {
+					it.Before(func() {
+						analyzer.SkipLayers = true
+					})
+
+					it("should write analyzed TOML", func() {
+						err := analyzer.Analyze(image)
+						h.AssertNil(t, err)
+
+						b, err := ioutil.ReadFile(analyzer.AnalyzedPath)
+						h.AssertNil(t, err)
+
+						entries := strings.Split(string(b), "\n")
+						h.AssertContains(t, entries, `repository = "image-repo-name"`)
+						h.AssertContains(t, entries, `digest = "s0m3D1g3sT"`)
+						h.AssertContains(t, entries, `[metadata]`)
+					})
+
+					it("does not write buildpack layers", func() {
+						err := analyzer.Analyze(image)
+						h.AssertNil(t, err)
+
+						fileInfos, err := ioutil.ReadDir(layerDir)
+						h.AssertNil(t, err)
+
+						h.AssertEq(t, len(fileInfos), 0)
+					})
+				})
 			})
 		})
 

diff --git a/cmd/analyzer/main.go b/cmd/analyzer/main.go
@@ -30,6 +30,7 @@ var (
 	useHelpers   bool
 	uid          int
 	gid          int
+	skipLayers   bool
 )
 
 func init() {
@@ -41,6 +42,7 @@ func init() {
 	cmd.FlagUID(&uid)
 	cmd.FlagUseDaemon(&useDaemon)
 	cmd.FlagUseCredHelpers(&useHelpers)
+	cmd.FlagSkipLayers(&skipLayers)
 }
 
 func main() {
@@ -79,6 +81,7 @@ func analyzer() error {
 		Err:          log.New(os.Stderr, "", 0),
 		UID:          uid,
 		GID:          gid,
+		SkipLayers:   skipLayers,
 	}
 
 	var err error

diff --git a/cmd/cmd.go b/cmd/cmd.go
@@ -38,6 +38,7 @@ const (
 	EnvUID            = "CNB_USER_ID"
 	EnvGID            = "CNB_GROUP_ID"
 	EnvRegistryAuth   = "CNB_REGISTRY_AUTH"
+	EnvSkipLayers     = "CNB_SKIP_LAYERS" // defaults to false
 )
 
 func FlagAnalyzedPath(dir *string) {
@@ -108,6 +109,10 @@ func FlagUseDaemon(use *bool) {
 	flag.BoolVar(use, "daemon", boolEnv(EnvUseDaemon), "export to docker daemon")
 }
 
+func FlagSkipLayers(skip *bool) {
+	flag.BoolVar(skip, "skip-layers", boolEnv(EnvSkipLayers), "do not provide layer metadata to buildpacks")
+}
+
 const (
 	CodeFailed = 1
 	// 2: reserved