Add --run-image for pack build

pack.go

@@ -79,11 +79,17 @@ type PackBuild struct {
 	sbomOutputDir string
 	volumes       []string
 	gid           string
+	runImage      string
 
 	// TODO: remove after deprecation period
 	noPull bool
 }
 
+func (pb PackBuild) WithRunImage(runImage string) PackBuild {
+	pb.runImage = runImage
+	return pb
+}
+
 func (pb PackBuild) WithBuildpacks(buildpacks ...string) PackBuild {
 	pb.buildpacks = append(pb.buildpacks, buildpacks...)
 	return pb
@@ -215,6 +221,10 @@ func (pb PackBuild) Execute(name, path string) (Image, fmt.Stringer, error) {
 		args = append(args, "--gid", pb.gid)
 	}
 
+	if pb.runImage != "" {
+		args = append(args, "--run-image", pb.runImage)
+	}
+
 	buildLogBuffer := bytes.NewBuffer(nil)
 	err := pb.executable.Execute(pexec.Execution{
 		Args:   args,

pack_test.go

@@ -302,6 +302,27 @@ func testPack(t *testing.T, context spec.G, it spec.S) {
 			})
 		})
 
+		context("when given optional run image", func() {
+			it("includes the --run-image option", func() {
+				image, logs, err := pack.Build.
+					WithRunImage("custom").
+					Execute("myapp", "/some/app/path")
+
+				Expect(err).NotTo(HaveOccurred())
+				Expect(image).To(Equal(occam.Image{
+					ID: "some-image-id",
+				}))
+				Expect(logs.String()).To(Equal("some stdout output\nsome stderr output\n"))
+
+				Expect(executable.ExecuteCall.Receives.Execution.Args).To(Equal([]string{
+					"build", "myapp",
+					"--path", "/some/app/path",
+					"--run-image", "custom",
+				}))
+				Expect(dockerImageInspectClient.ExecuteCall.Receives.Ref).To(Equal("myapp"))
+			})
+		})
+
 		context("when given optional gid", func() {
 			it("includes the --gid option and given argument on all commands", func() {
 				image, logs, err := pack.Build.