Symlink node_modules/.cache to tempdir (#661)

Author: c0d1ngm0nk3y

README.md

@@ -40,9 +40,10 @@ file that looks like the following:
 
 ## Configuration
 
-| Environment Variable          | Description                                                                                                                                                               |
-|-------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| `$BP_NPM_VERSION`     | If set, this custom version of `npm` will be used instead of the one provided by the `nodejs` installation.                                                                       |
+| Environment Variable        | Description                                                                                                                                                               |
+|-----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `$BP_NPM_VERSION`           | If set, this custom version of `npm` will be used instead of the one provided by the `nodejs` installation.                                                               |
+| `$BP_KEEP_NODE_BUILD_CACHE` | If set to `true` (default `false`), the folder `node_modules/.cache` will not be removed after the build, but will be readonly at runtime.                                |
 
 ## Usage
 

build.go

@@ -18,6 +18,8 @@ import (
 	"github.com/paketo-buildpacks/packit/v2/scribe"
 )
 
+const NODE_MODULES_CACHE = "node_modules_cache"
+
 //go:generate faux --interface BuildManager --output fakes/build_manager.go
 type BuildManager interface {
 	Resolve(workingDir string) (BuildProcess, bool, error)
@@ -282,6 +284,21 @@ func Build(entryResolver EntryResolver,
 					return packit.BuildResult{}, err
 				}
 
+				keepBuildCache, _ := environment.Lookup("BP_KEEP_NODE_BUILD_CACHE")
+				if keepBuildCache != "true" {
+					linkName := filepath.Join(layer.Path, "node_modules", ".cache")
+					err = os.RemoveAll(linkName)
+					if err != nil {
+						return packit.BuildResult{}, err
+					}
+
+					cacheFolder := filepath.Join(os.TempDir(), NODE_MODULES_CACHE)
+					err = os.Symlink(cacheFolder, linkName)
+					if err != nil {
+						return packit.BuildResult{}, err
+					}
+				}
+
 				if build {
 					err = symlinkResolver.Copy(filepath.Join(projectPath, "package-lock.json"), buildLayerPath, layer.Path)
 					if err != nil {

build_test.go

@@ -28,6 +28,7 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		layersDir  string
 		workingDir string
 		cnbDir     string
+		tempDir    string
 
 		processLayerDir   string
 		processWorkingDir string
@@ -60,6 +61,9 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		cnbDir, err = os.MkdirTemp("", "cnb")
 		Expect(err).NotTo(HaveOccurred())
 
+		tempDir = t.TempDir()
+		t.Setenv("TMPDIR", tempDir)
+
 		t.Setenv("BP_NODE_PROJECT_PATH", "")
 
 		buildProcess = &fakes.BuildProcess{}
@@ -423,6 +427,38 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 			Expect(symlinkResolver.ResolveCall.Receives.LockfilePath).To(Equal(filepath.Join(workingDir, "package-lock.json")))
 			Expect(symlinkResolver.ResolveCall.Receives.LayerPath).To(Equal(filepath.Join(layersDir, "launch-modules")))
 		})
+
+		it("symlinks node_modules/.cache to tmp/node_modules_cache in order to work for the run user", func() {
+			err := os.MkdirAll(filepath.Join(tempDir, "node_modules_cache", "temp-content"), os.ModePerm)
+			Expect(err).NotTo(HaveOccurred())
+			result, err := build(packit.BuildContext{
+				BuildpackInfo: packit.BuildpackInfo{
+					SBOMFormats: []string{"application/vnd.cyclonedx+json", "application/spdx+json", "application/vnd.syft+json"},
+				},
+				Platform: packit.Platform{
+					Path: "some-platform-path",
+				},
+				WorkingDir: workingDir,
+				Layers:     packit.Layers{Path: layersDir},
+				CNBPath:    cnbDir,
+				Plan: packit.BuildpackPlan{
+					Entries: []packit.BuildpackPlanEntry{
+						{Name: "node_modules"},
+					},
+				},
+			})
+			Expect(err).NotTo(HaveOccurred())
+
+			Expect(len(result.Layers)).To(Equal(2))
+
+			launchLayer := result.Layers[0]
+			Expect(launchLayer.Name).To(Equal("launch-modules"))
+			Expect(launchLayer.Path).To(Equal(filepath.Join(layersDir, "launch-modules")))
+
+			linkedTmpContent := filepath.Join(launchLayer.Path, "node_modules", ".cache", "temp-content")
+			_, err = os.Stat(linkedTmpContent)
+			Expect(err).NotTo(HaveOccurred())
+		})
 	})
 
 	context("when node_modules is required at build and launch", func() {
@@ -674,6 +710,39 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 			Expect(symlinkResolver.CopyCall.Receives.SourceLayerPath).To(Equal(filepath.Join(buildLayer.Path)))
 			Expect(symlinkResolver.CopyCall.Receives.TargetLayerPath).To(Equal(filepath.Join(launchLayer.Path)))
 		})
+
+		it("symlinks node_modules/.cache to tmp/node_modules_cache in order to work for the run user", func() {
+			err := os.MkdirAll(filepath.Join(tempDir, "node_modules_cache", "temp-content"), os.ModePerm)
+			Expect(err).NotTo(HaveOccurred())
+			result, err := build(packit.BuildContext{
+				BuildpackInfo: packit.BuildpackInfo{
+					SBOMFormats: []string{"application/vnd.cyclonedx+json", "application/spdx+json", "application/vnd.syft+json"},
+				},
+				Platform: packit.Platform{
+					Path: "some-platform-path",
+				},
+				WorkingDir: workingDir,
+				Layers:     packit.Layers{Path: layersDir},
+				CNBPath:    cnbDir,
+				Plan: packit.BuildpackPlan{
+					Entries: []packit.BuildpackPlanEntry{
+						{Name: "node_modules"},
+					},
+				},
+			})
+			Expect(err).NotTo(HaveOccurred())
+
+			Expect(len(result.Layers)).To(Equal(3))
+
+			launchLayer := result.Layers[1]
+			Expect(launchLayer.Name).To(Equal("launch-modules"))
+			Expect(launchLayer.Path).To(Equal(filepath.Join(layersDir, "launch-modules")))
+
+			linkedTmpContent := filepath.Join(launchLayer.Path, "node_modules", ".cache", "temp-content")
+			_, err = os.Stat(linkedTmpContent)
+			Expect(err).NotTo(HaveOccurred())
+		})
+
 	})
 
 	context("when one npmrc binding is detected", func() {
@@ -768,6 +837,10 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 				if err != nil {
 					return err
 				}
+				err = os.MkdirAll(filepath.Join(ld, "node_modules"), os.ModePerm)
+				if err != nil {
+					return err
+				}
 
 				return nil
 			}

buildpack.toml

@@ -32,6 +32,11 @@ api = "0.7"
     name = "BP_NPM_VERSION"
     description = "configures a custom npm version"
 
+	[[metadata.configurations]]
+    name = "BP_KEEP_NODE_BUILD_CACHE"
+    default = "false"
+    description = "keep the 'node_modules/.cache' folder after the build (will be readonly at runtime)'"
+
   [[metadata.configurations]]
 	  name = "NODE_HOME"
     description = "path the Node.js installation"
@@ -45,5 +50,6 @@ api = "0.7"
     default = "error"
     description = "configures npm output verbosity"
 
+
 [[stacks]]
   id = "*"

cmd/setup-symlinks/internal/run.go

@@ -42,7 +42,13 @@ func Run(executablePath, appDir string, symlinkResolver npminstall.SymlinkResolv
 		return err
 	}
 
-	return createSymlink(filepath.Join(layerPath, "node_modules"), linkPath)
+	err = createSymlink(filepath.Join(layerPath, "node_modules"), linkPath)
+	if err != nil {
+		return err
+	}
+
+	cacheFolder := filepath.Join(os.TempDir(), npminstall.NODE_MODULES_CACHE)
+	return os.Mkdir(cacheFolder, os.ModePerm)
 }
 
 func resolveWorkspaceModules(symlinkResolver npminstall.SymlinkResolver, appDir, layerPath string) error {

cmd/setup-symlinks/internal/run_test.go

@@ -41,6 +41,7 @@ func testRun(t *testing.T, context spec.G, it spec.S) {
 
 		tmpDir, err = os.MkdirTemp("", "tmp")
 		Expect(err).NotTo(HaveOccurred())
+		t.Setenv("TMPDIR", tmpDir)
 
 		Expect(os.Symlink(filepath.Join(tmpDir, "node_modules"), filepath.Join(appDir, "node_modules"))).To(Succeed())
 

integration/init_test.go

@@ -126,6 +126,7 @@ func TestIntegration(t *testing.T) {
 	suite("EmptyNodeModules", testEmptyNodeModules)
 	suite("Logging", testLogging)
 	suite("NativeModules", testNativeModules)
+	suite("NodeModulesCache", testReact)
 	suite("NoNodeModules", testNoNodeModules)
 	suite("Npmrc", testNpmrc)
 	suite("PackageLockMismatch", testPackageLockMismatch)

integration/react_test.go

@@ -0,0 +1,99 @@
+package integration_test
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/paketo-buildpacks/occam"
+	"github.com/sclevine/spec"
+
+	. "github.com/onsi/gomega"
+	. "github.com/paketo-buildpacks/occam/matchers"
+)
+
+func testReact(t *testing.T, context spec.G, it spec.S) {
+	var (
+		Expect     = NewWithT(t).Expect
+		Eventually = NewWithT(t).Eventually
+
+		pack         occam.Pack
+		docker       occam.Docker
+		imageIDs     map[string]struct{}
+		containerIDs map[string]struct{}
+
+		name   string
+		source string
+
+		pullPolicy = "never"
+	)
+
+	it.Before(func() {
+		imageIDs = make(map[string]struct{})
+		containerIDs = make(map[string]struct{})
+
+		pack = occam.NewPack().WithNoColor()
+		docker = occam.NewDocker()
+
+		var err error
+		name, err = occam.RandomName()
+		Expect(err).NotTo(HaveOccurred())
+
+		if settings.Extensions.UbiNodejsExtension.Online != "" {
+			pullPolicy = "always"
+		}
+
+	})
+
+	it.After(func() {
+		for id := range containerIDs {
+			Expect(docker.Container.Remove.Execute(id)).To(Succeed())
+		}
+
+		for id := range imageIDs {
+			Expect(docker.Image.Remove.Execute(id)).To(Succeed())
+		}
+
+		Expect(os.RemoveAll(source)).To(Succeed())
+	})
+
+	context("when the app is a react app", func() {
+		it("works", func() {
+			var err error
+			source, err = occam.Source(filepath.Join("testdata", "react_app"))
+			Expect(err).NotTo(HaveOccurred())
+
+			build := pack.Build.
+				WithPullPolicy(pullPolicy).
+				WithExtensions(
+					settings.Extensions.UbiNodejsExtension.Online,
+				).
+				WithBuildpacks(
+					settings.Buildpacks.NodeEngine.Online,
+					settings.Buildpacks.NPMInstall.Online,
+					settings.Buildpacks.BuildPlan.Online,
+				)
+
+			image, logs, err := build.Execute(name, source)
+			Expect(err).NotTo(HaveOccurred(), logs.String)
+
+			container, err := docker.Container.Run.
+				WithCommand("npm start").
+				WithEnv(map[string]string{"PORT": "8080"}).
+				WithPublish("8080").
+				Execute(image.ID)
+			Expect(err).NotTo(HaveOccurred())
+
+			containerIDs[container.ID] = struct{}{}
+
+			Eventually(container).Should(BeAvailable())
+
+			Eventually(func() string {
+				cLogs, err := docker.Container.Logs.Execute(container.ID)
+				Expect(err).NotTo(HaveOccurred())
+				return cLogs.String()
+			}).WithTimeout(3 * time.Second).Should(ContainSubstring("webpack compiled successfully"))
+		})
+	})
+}

integration/testdata/react_app/package.json

@@ -0,0 +1,38 @@
+{
+  "name": "react-app",
+  "version": "0.1.0",
+  "private": true,
+  "dependencies": {
+    "@testing-library/jest-dom": "^5.17.0",
+    "@testing-library/react": "^13.4.0",
+    "@testing-library/user-event": "^13.5.0",
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0",
+    "react-scripts": "5.0.1",
+    "web-vitals": "^2.1.4"
+  },
+  "scripts": {
+    "start": "react-scripts start",
+    "build": "react-scripts build",
+    "test": "react-scripts test",
+    "eject": "react-scripts eject"
+  },
+  "eslintConfig": {
+    "extends": [
+      "react-app",
+      "react-app/jest"
+    ]
+  },
+  "browserslist": {
+    "production": [
+      ">0.2%",
+      "not dead",
+      "not op_mini all"
+    ],
+    "development": [
+      "last 1 chrome version",
+      "last 1 firefox version",
+      "last 1 safari version"
+    ]
+  }
+}

integration/testdata/react_app/plan.toml

@@ -0,0 +1,11 @@
+[[requires]]
+  name = "node"
+
+  [requires.metadata]
+    launch = true
+
+[[requires]]
+  name = "node_modules"
+
+  [requires.metadata]
+    launch = true