"Generate phase" fetching uids and gids according to the build context

generate.go

@@ -5,22 +5,27 @@ import (
 	_ "embed"
 	"os"
 	"path/filepath"
+	"regexp"
+	"strconv"
 	"strings"
 	"text/template"
 
 	"github.com/Masterminds/semver/v3"
+	"github.com/paketo-buildpacks/libnodejs"
 	"github.com/paketo-buildpacks/packit/v2"
 	"github.com/paketo-buildpacks/packit/v2/draft"
-	"github.com/paketo-buildpacks/libnodejs"
 	postal "github.com/paketo-buildpacks/packit/v2/postal"
 	"github.com/paketo-buildpacks/packit/v2/scribe"
 )
 
 var PACKAGES = "make gcc gcc-c++ libatomic_ops git openssl-devel nodejs npm nodejs-nodemon nss_wrapper which"
 
-// Should be externalized
-var CNB_USER_ID = 1000
-var CNB_GROUP_ID = 1000
+var DEFAULT_USER_ID = 1002
+var DEFAULT_GROUP_ID = 1000
+
+type DuringBuildPermissions struct {
+	CNB_USER_ID, CNB_GROUP_ID int
+}
 
 //go:embed templates/build.Dockerfile
 var buildDockerfileTemplate string
@@ -45,13 +50,13 @@ type DependencyManager interface {
 	GenerateBillOfMaterials(dependencies ...postal.Dependency) []packit.BOMEntry
 }
 
-func Generate(dependencyManager DependencyManager, logger scribe.Emitter) packit.GenerateFunc {
+func Generate(dependencyManager DependencyManager, logger scribe.Emitter, duringBuildPermissions DuringBuildPermissions) packit.GenerateFunc {
 	return func(context packit.GenerateContext) (packit.GenerateResult, error) {
 		logger.Title("%s %s", context.Info.Name, context.Info.Version)
 		logger.Process("Resolving Node Engine version")
 
 		entryResolver := draft.NewPlanner()
-		entry, allEntries := libnodejs.ResolveNodeVersion(entryResolver.Resolve, context.Plan);
+		entry, allEntries := libnodejs.ResolveNodeVersion(entryResolver.Resolve, context.Plan)
 		if entry.Name == "" {
 			return packit.GenerateResult{}, packit.Fail.WithMessage("Node.js no longer requested by build plan")
 		}
@@ -73,29 +78,23 @@ func Generate(dependencyManager DependencyManager, logger scribe.Emitter) packit
 		// These variables have to be fetched from the env
 		CNB_STACK_ID := os.Getenv("CNB_STACK_ID")
 
-		/* Creating build.Dockerfile */
-
-		buildDockerfileProps := BuildDockerfileProps{
+		// Generating build.Dockerfile
+		buildDockerfileContent, err := FillPropsToTemplate(BuildDockerfileProps{
 			NODEJS_VERSION: NODEJS_VERSION,
-			CNB_USER_ID:    CNB_USER_ID,
-			CNB_GROUP_ID:   CNB_GROUP_ID,
+			CNB_USER_ID:    duringBuildPermissions.CNB_USER_ID,
+			CNB_GROUP_ID:   duringBuildPermissions.CNB_GROUP_ID,
 			CNB_STACK_ID:   CNB_STACK_ID,
 			PACKAGES:       "make gcc gcc-c++ libatomic_ops git openssl-devel nodejs npm nodejs-nodemon nss_wrapper which",
-		}
-
-		buildDockerfileContent, err := FillPropsToTemplate(buildDockerfileProps, buildDockerfileTemplate)
+		}, buildDockerfileTemplate)
 
 		if err != nil {
 			return packit.GenerateResult{}, err
 		}
 
-		/* Creating run.Dockerfile */
-
-		RunDockerfileProps := RunDockerfileProps{
+		// Generating run.Dockerfile
+		runDockerfileContent, err := FillPropsToTemplate(RunDockerfileProps{
 			Source: dependency.Source,
-		}
-
-		runDockerfileContent, err := FillPropsToTemplate(RunDockerfileProps, runDockerfileTemplate)
+		}, runDockerfileTemplate)
 
 		if err != nil {
 			return packit.GenerateResult{}, err
@@ -123,5 +122,43 @@ func FillPropsToTemplate(properties interface{}, templateString string) (result
 	}
 
 	return buf.String(), nil
+}
+
+func GetDuringBuildPermissions(filepath string) DuringBuildPermissions {
+
+	defaultPermissions := DuringBuildPermissions{
+		CNB_USER_ID:  DEFAULT_USER_ID,
+		CNB_GROUP_ID: DEFAULT_GROUP_ID,
+	}
+	re := regexp.MustCompile(`cnb:x:(\d+):(\d+)::`)
+
+	etcPasswdFile, err := os.ReadFile(filepath)
 
+	if err != nil {
+		return defaultPermissions
+	}
+	etcPasswdContent := string(etcPasswdFile)
+
+	matches := re.FindStringSubmatch(etcPasswdContent)
+
+	if len(matches) != 3 {
+		return defaultPermissions
+	}
+
+	CNB_USER_ID, err := strconv.Atoi(matches[1])
+
+	if err != nil {
+		return defaultPermissions
+	}
+
+	CNB_GROUP_ID, err := strconv.Atoi(matches[2])
+
+	if err != nil {
+		return defaultPermissions
+	}
+
+	return DuringBuildPermissions{
+		CNB_USER_ID:  CNB_USER_ID,
+		CNB_GROUP_ID: CNB_GROUP_ID,
+	}
 }

generate_test.go

@@ -48,15 +48,13 @@ func testFillPropsToTemplate(t *testing.T, context spec.G, it spec.S) {
 
 		it("Should fill with properties the template/build.Dockerfile", func() {
 
-			buildDockerfileProps := BuildDockerfileProps{
+			output, err := ubinodejsextension.FillPropsToTemplate(BuildDockerfileProps{
 				NODEJS_VERSION: 16,
 				CNB_USER_ID:    1000,
 				CNB_GROUP_ID:   1000,
 				CNB_STACK_ID:   "",
 				PACKAGES:       "make gcc gcc-c++ libatomic_ops git openssl-devel nodejs npm nodejs-nodemon nss_wrapper which",
-			}
-
-			output, err := ubinodejsextension.FillPropsToTemplate(buildDockerfileProps, buildDockerfileTemplate)
+			}, buildDockerfileTemplate)
 
 			Expect(err).NotTo(HaveOccurred())
 			Expect(output).To(Equal(`ARG base_image
@@ -92,6 +90,99 @@ RUN echo "CNB_STACK_ID: "`))
 	})
 }
 
+func testFetchingPermissionsFromEtchPasswdFile(t *testing.T, context spec.G, it spec.S) {
+
+	var (
+		Expect = NewWithT(t).Expect
+		tmpDir string
+		path   string
+		err    error
+	)
+
+	context("/etc/passwd exists and has the cnb user", func() {
+
+		it("It should return the permissions specified for the cnb user", func() {
+			tmpDir, err = os.MkdirTemp("", "")
+			Expect(err).NotTo(HaveOccurred())
+
+			path = filepath.Join(tmpDir, "/passwd")
+
+			Expect(os.WriteFile(path, []byte(`root:x:0:0:root:/root:/bin/bash
+bin:x:1:1:bin:/bin:/sbin/nologin
+daemon:x:2:2:daemon:/sbin:/sbin/nologin
+adm:x:3:4:adm:/var/adm:/sbin/nologin
+lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
+sync:x:5:0:sync:/sbin:/bin/sync
+shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
+halt:x:7:0:halt:/sbin:/sbin/halt
+mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
+operator:x:11:0:operator:/root:/sbin/nologin
+games:x:12:100:games:/usr/games:/sbin/nologin
+ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
+cnb:x:1234:2345::/home/cnb:/bin/bash
+nobody:x:65534:65534:Kernel Overflow User:/:/sbin/nologin
+`), 0600)).To(Succeed())
+
+			duringBuilderPermissions := ubinodejsextension.GetDuringBuildPermissions(path)
+
+			Expect(duringBuilderPermissions).To(Equal(
+				ubinodejsextension.DuringBuildPermissions{
+					CNB_USER_ID:  1234,
+					CNB_GROUP_ID: 2345},
+			))
+		})
+	})
+
+	context("/etc/passwd exists and does NOT have the cnb user", func() {
+
+		it("It should return the default permissions", func() {
+			tmpDir, err = os.MkdirTemp("", "")
+			Expect(err).NotTo(HaveOccurred())
+
+			path = filepath.Join(tmpDir, "/passwd")
+
+			Expect(os.WriteFile(path, []byte(`root:x:0:0:root:/root:/bin/bash
+bin:x:1:1:bin:/bin:/sbin/nologin
+daemon:x:2:2:daemon:/sbin:/sbin/nologin
+adm:x:3:4:adm:/var/adm:/sbin/nologin
+lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
+sync:x:5:0:sync:/sbin:/bin/sync
+shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
+halt:x:7:0:halt:/sbin:/sbin/halt
+mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
+operator:x:11:0:operator:/root:/sbin/nologin
+games:x:12:100:games:/usr/games:/sbin/nologin
+ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
+nobody:x:65534:65534:Kernel Overflow User:/:/sbin/nologin
+`), 0600)).To(Succeed())
+
+			duringBuilderPermissions := ubinodejsextension.GetDuringBuildPermissions(path)
+
+			Expect(duringBuilderPermissions).To(Equal(
+				ubinodejsextension.DuringBuildPermissions{
+					CNB_USER_ID:  ubinodejsextension.DEFAULT_USER_ID,
+					CNB_GROUP_ID: ubinodejsextension.DEFAULT_GROUP_ID},
+			))
+		})
+	})
+
+	context("/etc/passwd does NOT exist", func() {
+
+		it("It should return the default permissions", func() {
+			tmpDir, err = os.MkdirTemp("", "")
+			Expect(err).NotTo(HaveOccurred())
+
+			duringBuilderPermissions := ubinodejsextension.GetDuringBuildPermissions(tmpDir)
+
+			Expect(duringBuilderPermissions).To(Equal(
+				ubinodejsextension.DuringBuildPermissions{
+					CNB_USER_ID:  ubinodejsextension.DEFAULT_USER_ID,
+					CNB_GROUP_ID: ubinodejsextension.DEFAULT_GROUP_ID},
+			))
+		})
+	})
+}
+
 func testGenerate(t *testing.T, context spec.G, it spec.S) {
 
 	var (
@@ -104,21 +195,21 @@ func testGenerate(t *testing.T, context spec.G, it spec.S) {
 		err                  error
 		cnbDir               string
 		BuildDockerfileProps = ubinodejsextension.BuildDockerfileProps{
-			CNB_USER_ID:  ubinodejsextension.CNB_USER_ID,
-			CNB_GROUP_ID: ubinodejsextension.CNB_GROUP_ID,
+			CNB_USER_ID:  1002,
+			CNB_GROUP_ID: 1000,
 			CNB_STACK_ID: "",
 			PACKAGES:     ubinodejsextension.PACKAGES,
 		}
-		generate packit.GenerateFunc
-		buffer   *bytes.Buffer
+		generate          packit.GenerateFunc
+		buffer            *bytes.Buffer
+		logger            scribe.Emitter
+		dependencyManager postal.Service
 	)
 
 	it.Before(func() {
 		buffer = bytes.NewBuffer(nil)
-		logger := scribe.NewEmitter(buffer)
-		dependencyManager := postal.NewService(cargo.NewTransport())
-		generate = ubinodejsextension.Generate(dependencyManager, logger)
-
+		logger = scribe.NewEmitter(buffer)
+		dependencyManager = postal.NewService(cargo.NewTransport())
 	})
 
 	context("Generate called with NO node in buildplan", func() {
@@ -127,6 +218,8 @@ func testGenerate(t *testing.T, context spec.G, it spec.S) {
 			workingDir = t.TempDir()
 			Expect(err).NotTo(HaveOccurred())
 
+			generate = ubinodejsextension.Generate(dependencyManager, logger, ubinodejsextension.DuringBuildPermissions{CNB_USER_ID: 1002, CNB_GROUP_ID: 1000})
+
 			err = toml.NewEncoder(buf).Encode(testBuildPlan)
 			Expect(err).NotTo(HaveOccurred())
 
@@ -159,6 +252,8 @@ func testGenerate(t *testing.T, context spec.G, it spec.S) {
 			workingDir = t.TempDir()
 			cnbDir, err = os.MkdirTemp("", "cnb")
 
+			generate = ubinodejsextension.Generate(dependencyManager, logger, ubinodejsextension.DuringBuildPermissions{CNB_USER_ID: 1002, CNB_GROUP_ID: 1000})
+
 			err = toml.NewEncoder(buf).Encode(testBuildPlan)
 			Expect(err).NotTo(HaveOccurred())
 
@@ -169,7 +264,6 @@ func testGenerate(t *testing.T, context spec.G, it spec.S) {
 
 			err = os.Chdir(workingDir)
 			Expect(err).NotTo(HaveOccurred())
-
 		})
 
 		it.After(func() {
@@ -610,6 +704,8 @@ func testGenerate(t *testing.T, context spec.G, it spec.S) {
 			workingDir = t.TempDir()
 			cnbDir, err = os.MkdirTemp("", "cnb")
 
+			generate = ubinodejsextension.Generate(dependencyManager, logger, ubinodejsextension.DuringBuildPermissions{CNB_USER_ID: 1002, CNB_GROUP_ID: 1000})
+
 			err = toml.NewEncoder(buf).Encode(testBuildPlan)
 			Expect(err).NotTo(HaveOccurred())
 

init_test.go

@@ -12,5 +12,6 @@ func TestUnitNode(t *testing.T) {
 	suite("Detect", testDetect)
 	suite("Generate", testGenerate)
 	suite("Dockerfile Creation", testFillPropsToTemplate)
+	suite("Fetching during build permissions", testFetchingPermissionsFromEtchPasswdFile)
 	suite.Run(t)
 }

integration/openssl_test.go

@@ -70,7 +70,6 @@ func testOpenSSL(t *testing.T, context spec.G, it spec.S) {
 					WithEnv(map[string]string{
 						"BP_NODE_VERSION": "16.*.*",
 					}).
-					WithNetwork("host").
 					WithPullPolicy("always").
 					Execute(name, source)
 				Expect(err).ToNot(HaveOccurred(), logs.String)
@@ -113,7 +112,6 @@ func testOpenSSL(t *testing.T, context spec.G, it spec.S) {
 					WithEnv(map[string]string{
 						"BP_NODE_VERSION": "18.*.*",
 					}).
-					WithNetwork("host").
 					WithPullPolicy("always").
 					Execute(name, source)
 				Expect(err).ToNot(HaveOccurred(), logs.String)

integration/optimize_memory_test.go

@@ -59,7 +59,6 @@ func testOptimizeMemory(t *testing.T, context spec.G, it spec.S) {
 				settings.Buildpacks.Processes.Online,
 			).
 			WithEnv(map[string]string{"BP_NODE_OPTIMIZE_MEMORY": "true"}).
-			WithNetwork("host").
 			WithPullPolicy("always").
 			Execute(name, source)
 		Expect(err).NotTo(HaveOccurred(), logs.String())

integration/project_path_test.go

@@ -68,7 +68,6 @@ func testProjectPath(t *testing.T, context spec.G, it spec.S) {
 				WithEnv(map[string]string{
 					"BP_NODE_PROJECT_PATH": "hello_world_server",
 				}).
-				WithNetwork("host").
 				WithPullPolicy("always").
 				Execute(name, source)
 			Expect(err).ToNot(HaveOccurred(), logs.String)

integration/provides_test.go

@@ -60,7 +60,6 @@ func testProvides(t *testing.T, context spec.G, it spec.S) {
 					settings.Buildpacks.NodeEngine.Online,
 					settings.Buildpacks.BuildPlan.Online,
 				).
-				WithNetwork("host").
 				WithPullPolicy("always").
 				Execute(name, source)
 			Expect(err).ToNot(HaveOccurred(), logs.String)

integration/simple_app_test.go

@@ -77,7 +77,6 @@ func testSimple(t *testing.T, context spec.G, it spec.S) {
 						settings.Buildpacks.BuildPlan.Online,
 					).
 					WithSBOMOutputDir(sbomDir).
-					WithNetwork("host").
 					WithPullPolicy("always").
 					Execute(name, source)
 				Expect(err).ToNot(HaveOccurred(), logs.String)
@@ -170,7 +169,6 @@ func testSimple(t *testing.T, context spec.G, it spec.S) {
 						settings.Buildpacks.NodeEngine.Online,
 						settings.Buildpacks.BuildPlan.Online,
 					).
-					WithNetwork("host").
 					WithPullPolicy("always").
 					Execute(name, source)
 				Expect(err).ToNot(HaveOccurred(), logs.String)
@@ -249,7 +247,6 @@ func testSimple(t *testing.T, context spec.G, it spec.S) {
 						settings.Buildpacks.BuildPlan.Online,
 					).
 					WithSBOMOutputDir(sbomDir).
-					WithNetwork("host").
 					WithPullPolicy("always").
 					Execute(name, source)
 				Expect(err).ToNot(HaveOccurred(), logs.String)
@@ -341,7 +338,6 @@ func testSimple(t *testing.T, context spec.G, it spec.S) {
 						settings.Buildpacks.BuildPlan.Online,
 					).
 					WithSBOMOutputDir(sbomDir).
-					WithNetwork("host").
 					WithPullPolicy("always").
 					Execute(name, source)
 				Expect(err).ToNot(HaveOccurred(), logs.String)
@@ -444,7 +440,6 @@ func testSimple(t *testing.T, context spec.G, it spec.S) {
 				).
 				WithEnv(map[string]string{"BP_NODE_VERSION": "~14"}).
 				WithSBOMOutputDir(sbomDir).
-				WithNetwork("host").
 				WithPullPolicy("always").
 				Execute(name, source)