Mark the detected script executable

When the buildpack runs, it will locate the dist zip script to execute. If that script is found, then we also mark it as `0755`. This happens unconditionally, but we do not fail if there is an error. We just log a warning and proceed. It really shouldn't fail but maybe if the file had weird file permissions/ownership.

The choice to do this unconditionally is that it is slightly simpler. Checking and then setting is two operations. If thereis a preference to doing it that way, making the switch is easy enough. Just let me know

Signed-off-by: Daniel Mikusa <[email protected]>

distzip/build.go

@@ -22,6 +22,7 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/heroku/color"
 	"github.com/paketo-buildpacks/libpak/effect"
 	"github.com/paketo-buildpacks/libpak/sbom"
 
@@ -67,6 +68,11 @@ func (b Build) Build(context libcnb.BuildContext) (libcnb.BuildResult, error) {
 		return libcnb.BuildResult{}, fmt.Errorf("unable to create configuration resolver\n%w", err)
 	}
 
+	err = os.Chmod(s, 0755)
+	if err != nil {
+		b.Logger.Bodyf("%s Unable to make script executable\n%w", color.YellowString("WARNING:"), err.Error())
+	}
+
 	result.Processes = append(result.Processes,
 		libcnb.Process{Type: "dist-zip", Command: s},
 		libcnb.Process{Type: "task", Command: s},

distzip/build_test.go

@@ -128,6 +128,32 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		})
 	})
 
+	context("DistZip exists but isn't executable", func() {
+		var scriptPath string
+
+		it.Before(func() {
+			scriptPath = filepath.Join(ctx.Application.Path, "app", "bin", "test-script")
+			Expect(os.MkdirAll(filepath.Join(ctx.Application.Path, "app", "bin"), 0755)).To(Succeed())
+			Expect(os.WriteFile(scriptPath, []byte{}, 0644))
+		})
+
+		it("contributes processes and marks the script executable", func() {
+			result, err := distzip.Build{SBOMScanner: &sbomScanner}.Build(ctx)
+			Expect(err).NotTo(HaveOccurred())
+
+			Expect(result.Processes).To(ContainElements(
+				libcnb.Process{Type: "dist-zip", Command: scriptPath},
+				libcnb.Process{Type: "task", Command: scriptPath},
+				libcnb.Process{Type: "web", Command: scriptPath, Default: true},
+			))
+			sbomScanner.AssertCalled(t, "ScanLaunch", ctx.Application.Path, libcnb.SyftJSON, libcnb.CycloneDXJSON)
+
+			info, err := os.Stat(scriptPath)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(info.Mode().Perm().String()).To(Equal("-rwxr-xr-x"))
+		})
+	})
+
 	context("DistZip does not exists", func() {
 		it("passes plan entries to subsequent buildpacks", func() {
 			result, err := distzip.Build{}.Build(ctx)

go.mod

@@ -4,6 +4,7 @@ go 1.20
 
 require (
 	github.com/buildpacks/libcnb v1.30.1
+	github.com/heroku/color v0.0.6
 	github.com/onsi/gomega v1.31.1
 	github.com/paketo-buildpacks/libpak v1.68.1
 	github.com/sclevine/spec v1.4.0
@@ -15,7 +16,6 @@ require (
 	github.com/creack/pty v1.1.21 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/google/go-cmp v0.6.0 // indirect
-	github.com/heroku/color v0.0.6 // indirect
 	github.com/imdario/mergo v0.3.16 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect