Handle pre/post_compile scripts without shebangs.

[#156381551]

Signed-off-by: Tyler Phelan <[email protected]>

fixtures/with_hooks/bin/post_compile

@@ -1,6 +1,2 @@
-#!/usr/bin/env bash
-
-set -uexo pipefail
-
 echo 'Echo from app post compile'
 echo

src/python/hooks/hooks_app.go

@@ -1,9 +1,11 @@
 package hooks
 
 import (
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"regexp"
 
 	"github.com/cloudfoundry/libbuildpack"
 )
@@ -17,36 +19,38 @@ func init() {
 }
 
 func (h AppHook) BeforeCompile(compiler *libbuildpack.Stager) error {
-	path := filepath.Join(compiler.BuildDir(), "bin", "pre_compile")
+	return runHook("pre_compile", compiler)
+}
+
+func (h AppHook) AfterCompile(compiler *libbuildpack.Stager) error {
+	return runHook("post_compile", compiler)
+}
+
+func runHook(scriptName string, compiler *libbuildpack.Stager) error {
+	path := filepath.Join(compiler.BuildDir(), "bin", scriptName)
 	if exists, err := libbuildpack.FileExists(path); err != nil {
 		return err
 	} else if exists {
-		compiler.Logger().BeginStep("Running pre-compile hook")
+		compiler.Logger().BeginStep("Running " + scriptName + " hook")
 		if err := os.Chmod(path, 0755); err != nil {
 			return err
 		}
-		cmd := exec.Command(path)
-		cmd.Dir = compiler.BuildDir()
-		output, err := cmd.Output()
+
+		fileContents, err := ioutil.ReadFile(path)
 		if err != nil {
 			return err
 		}
-		compiler.Logger().Info("%s", output)
 
-	}
-	return nil
-}
+		shebangRegex := regexp.MustCompile("^\\s*#!")
+		hasShebang := shebangRegex.Match(fileContents)
 
-func (h AppHook) AfterCompile(compiler *libbuildpack.Stager) error {
-	path := filepath.Join(compiler.BuildDir(), "bin", "post_compile")
-	if exists, err := libbuildpack.FileExists(path); err != nil {
-		return err
-	} else if exists {
-		compiler.Logger().BeginStep("Running post-compile hook")
-		if err := os.Chmod(path, 0755); err != nil {
-			return err
+		var cmd *exec.Cmd
+		if hasShebang {
+			cmd = exec.Command(path)
+		} else {
+			cmd = exec.Command("/bin/sh", path)
 		}
-		cmd := exec.Command(path)
+
 		cmd.Dir = compiler.BuildDir()
 		output, err := cmd.Output()
 		if err != nil {
@@ -55,4 +59,5 @@ func (h AppHook) AfterCompile(compiler *libbuildpack.Stager) error {
 		compiler.Logger().Info("%s", output)
 	}
 	return nil
+
 }

src/python/hooks/hooks_test.go

@@ -39,7 +39,7 @@ var _ = Describe("Hooks", func() {
 		Expect(os.RemoveAll(buildDir)).To(Succeed())
 	})
 
-	Context("BeforeCompile", func() {
+	Describe("BeforeCompile", func() {
 		Context("bin/pre_compile exists", func() {
 			BeforeEach(func() {
 				Expect(os.Mkdir(filepath.Join(buildDir, "bin"), 0755)).To(Succeed())
@@ -51,10 +51,10 @@ var _ = Describe("Hooks", func() {
 				fileInfo, err := os.Stat(filepath.Join(buildDir, "bin", "pre_compile"))
 				Expect(err).ToNot(HaveOccurred())
 				Expect(fileInfo.Mode()).To(Equal(os.FileMode(0755)))
-				Expect(buffer.String()).To(ContainSubstring("Running pre-compile hook"))
+				Expect(buffer.String()).To(ContainSubstring("Running pre_compile hook"))
 			})
 
-			It("runs file", func() {
+			It("runs successfully", func() {
 				Expect(filepath.Join(buildDir, "fred.txt")).ToNot(BeARegularFile())
 
 				Expect(hook.BeforeCompile(stager)).To(Succeed())
@@ -64,15 +64,20 @@ var _ = Describe("Hooks", func() {
 			})
 		})
 
-		Context("bin/pre_compile does NOT exist", func() {
-			It("does nothing", func() {
-				Expect(hook.BeforeCompile(stager)).To(Succeed())
-				Expect(buffer.String()).NotTo(ContainSubstring("Running pre-compile hook"))
-			})
+		It("runs successfully when bin/pre_compile exists but has no shebang", func() {
+			Expect(os.Mkdir(filepath.Join(buildDir, "bin"), 0755)).To(Succeed())
+			Expect(ioutil.WriteFile(filepath.Join(buildDir, "bin", "pre_compile"), []byte("echo 'Hello world!'"), 0644)).To(Succeed())
+			Expect(hook.BeforeCompile(stager)).To(Succeed())
+			Expect(buffer.String()).To(ContainSubstring("Hello world!"))
+		})
+
+		It("does nothing when bin/pre_compile does NOT exist", func() {
+			Expect(hook.BeforeCompile(stager)).To(Succeed())
+			Expect(buffer.String()).NotTo(ContainSubstring("Running pre_compile hook"))
 		})
 	})
 
-	Context("AfterCompile", func() {
+	Describe("AfterCompile", func() {
 		Context("bin/post_compile exists", func() {
 			BeforeEach(func() {
 				Expect(os.Mkdir(filepath.Join(buildDir, "bin"), 0755)).To(Succeed())
@@ -83,9 +88,10 @@ var _ = Describe("Hooks", func() {
 				fileInfo, err := os.Stat(filepath.Join(buildDir, "bin", "post_compile"))
 				Expect(err).ToNot(HaveOccurred())
 				Expect(fileInfo.Mode()).To(Equal(os.FileMode(0755)))
-				Expect(buffer.String()).To(ContainSubstring("Running post-compile hook"))
+				Expect(buffer.String()).To(ContainSubstring("Running post_compile hook"))
 			})
-			It("runs file", func() {
+
+			It("runs successfully", func() {
 				Expect(filepath.Join(buildDir, "fred.txt")).ToNot(BeARegularFile())
 
 				Expect(hook.AfterCompile(stager)).To(Succeed())
@@ -94,11 +100,17 @@ var _ = Describe("Hooks", func() {
 				Expect(ioutil.ReadFile(filepath.Join(buildDir, "fred.txt"))).To(Equal([]byte("john")))
 			})
 		})
-		Context("bin/post_compile does NOT exist", func() {
-			It("does nothing", func() {
-				Expect(hook.AfterCompile(stager)).To(Succeed())
-				Expect(buffer.String()).NotTo(ContainSubstring("Running post-compile hook"))
-			})
+
+		It("runs successfully when bin/post_compile exists but has no shebang", func() {
+			Expect(os.Mkdir(filepath.Join(buildDir, "bin"), 0755)).To(Succeed())
+			Expect(ioutil.WriteFile(filepath.Join(buildDir, "bin", "post_compile"), []byte("echo 'Hello world!'"), 0644)).To(Succeed())
+			Expect(hook.AfterCompile(stager)).To(Succeed())
+			Expect(buffer.String()).To(ContainSubstring("Hello world!"))
+		})
+
+		It("does nothing when bin/post_compile does NOT exist", func() {
+			Expect(hook.AfterCompile(stager)).To(Succeed())
+			Expect(buffer.String()).NotTo(ContainSubstring("Running post_compile hook"))
 		})
 	})
 })