Remove built_at for more reproducible builds

- Now that the timestamp is not being added to the metadata we no longer
need to check to see if the sha is the same from previous builds to
prevent adding a new timestamp on the same bits.

build.go

@@ -16,11 +16,6 @@ type BuildProcess interface {
 	Execute(config GoBuildConfiguration) (binaries []string, err error)
 }
 
-//go:generate faux --interface ChecksumCalculator --output fakes/checksum_calculator.go
-type ChecksumCalculator interface {
-	Sum(paths ...string) (string, error)
-}
-
 //go:generate faux --interface PathManager --output fakes/path_manager.go
 type PathManager interface {
 	Setup(workspace, importPath string) (goPath, path string, err error)
@@ -40,7 +35,6 @@ type SBOMGenerator interface {
 func Build(
 	parser ConfigurationParser,
 	buildProcess BuildProcess,
-	checksumCalculator ChecksumCalculator,
 	pathManager PathManager,
 	clock chronos.Clock,
 	logs scribe.Emitter,
@@ -97,19 +91,6 @@ func Build(
 			return packit.BuildResult{}, err
 		}
 
-		sum, err := checksumCalculator.Sum(targetsLayer.Path)
-		if err != nil {
-			return packit.BuildResult{}, err
-		}
-
-		cachedSha, _ := targetsLayer.Metadata["cache_sha"].(string)
-		if cachedSha != sum {
-			targetsLayer.Metadata = map[string]interface{}{
-				"cache_sha": sum,
-				"built_at":  clock.Now().Format(time.RFC3339Nano),
-			}
-		}
-
 		err = pathManager.Teardown(goPath)
 		if err != nil {
 			return packit.BuildResult{}, err

build_test.go

@@ -3,12 +3,9 @@ package gobuild_test
 import (
 	"bytes"
 	"errors"
-	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
-	"time"
 
 	gobuild "github.com/paketo-buildpacks/go-build"
 	"github.com/paketo-buildpacks/go-build/fakes"
@@ -28,15 +25,13 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		layersDir  string
 		workingDir string
 		cnbDir     string
-		timestamp  time.Time
 		logs       *bytes.Buffer
 
-		buildProcess       *fakes.BuildProcess
-		pathManager        *fakes.PathManager
-		sourceRemover      *fakes.SourceRemover
-		parser             *fakes.ConfigurationParser
-		checksumCalculator *fakes.ChecksumCalculator
-		sbomGenerator      *fakes.SBOMGenerator
+		buildProcess  *fakes.BuildProcess
+		pathManager   *fakes.PathManager
+		sourceRemover *fakes.SourceRemover
+		parser        *fakes.ConfigurationParser
+		sbomGenerator *fakes.SBOMGenerator
 
 		build packit.BuildFunc
 	)
@@ -59,14 +54,6 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		pathManager.SetupCall.Returns.GoPath = "some-go-path"
 		pathManager.SetupCall.Returns.Path = "some-app-path"
 
-		timestamp = time.Now()
-		clock := chronos.NewClock(func() time.Time {
-			return timestamp
-		})
-
-		checksumCalculator = &fakes.ChecksumCalculator{}
-		checksumCalculator.SumCall.Returns.String = "some-checksum"
-
 		logs = bytes.NewBuffer(nil)
 
 		sourceRemover = &fakes.SourceRemover{}
@@ -84,9 +71,8 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		build = gobuild.Build(
 			parser,
 			buildProcess,
-			checksumCalculator,
 			pathManager,
-			clock,
+			chronos.DefaultClock,
 			scribe.NewEmitter(logs),
 			sourceRemover,
 			sbomGenerator,
@@ -118,10 +104,6 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		targets := result.Layers[0]
 		Expect(targets.Name).To(Equal("targets"))
 		Expect(targets.Path).To(Equal(filepath.Join(layersDir, "targets")))
-		Expect(targets.Metadata).To(Equal(map[string]interface{}{
-			"cache_sha": "some-checksum",
-			"built_at":  timestamp.Format(time.RFC3339Nano),
-		}))
 		Expect(targets.Build).To(BeFalse())
 		Expect(targets.Cache).To(BeFalse())
 		Expect(targets.Launch).To(BeTrue())
@@ -275,44 +257,6 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 		})
 	})
 
-	context("when the targets were previously built", func() {
-		it.Before(func() {
-			err := ioutil.WriteFile(filepath.Join(layersDir, "targets.toml"), []byte(fmt.Sprintf(`
-launch = true
-[metadata]
-	cache_sha = "some-checksum"
-	built_at = "%s"
-`, timestamp.Add(-10*time.Second).Format(time.RFC3339Nano))), 0600)
-			Expect(err).NotTo(HaveOccurred())
-		})
-
-		it("uses the cached layer", func() {
-			result, err := build(packit.BuildContext{
-				WorkingDir: workingDir,
-				CNBPath:    cnbDir,
-				Stack:      "some-stack",
-				BuildpackInfo: packit.BuildpackInfo{
-					Name:    "Some Buildpack",
-					Version: "some-version",
-				},
-				Layers: packit.Layers{Path: layersDir},
-			})
-			Expect(err).NotTo(HaveOccurred())
-
-			Expect(result.Layers).To(HaveLen(2))
-			targets := result.Layers[0]
-			Expect(targets.Name).To(Equal("targets"))
-			Expect(targets.Path).To(Equal(filepath.Join(layersDir, "targets")))
-			Expect(targets.Metadata).To(Equal(map[string]interface{}{
-				"cache_sha": "some-checksum",
-				"built_at":  timestamp.Add(-10 * time.Second).Format(time.RFC3339Nano),
-			}))
-			Expect(targets.Build).To(BeFalse())
-			Expect(targets.Cache).To(BeFalse())
-			Expect(targets.Launch).To(BeTrue())
-		})
-	})
-
 	context("failure cases", func() {
 		context("when the targets layer cannot be retrieved", func() {
 			it.Before(func() {
@@ -396,26 +340,6 @@ launch = true
 			})
 		})
 
-		context("when the checksum cannot be calculated", func() {
-			it.Before(func() {
-				checksumCalculator.SumCall.Returns.Error = errors.New("failed to calculate checksum")
-			})
-
-			it("returns an error", func() {
-				_, err := build(packit.BuildContext{
-					WorkingDir: workingDir,
-					CNBPath:    cnbDir,
-					Stack:      "some-stack",
-					BuildpackInfo: packit.BuildpackInfo{
-						Name:    "Some Buildpack",
-						Version: "some-version",
-					},
-					Layers: packit.Layers{Path: layersDir},
-				})
-				Expect(err).To(MatchError("failed to calculate checksum"))
-			})
-		})
-
 		context("when the go path cannot be torn down", func() {
 			it.Before(func() {
 				pathManager.TeardownCall.Returns.Error = errors.New("failed to teardown go path")

integration/build_flags_test.go

@@ -75,7 +75,7 @@ func testBuildFlags(t *testing.T, context spec.G, it spec.S) {
 			Eventually(container).Should(
 				Serve(
 					SatisfyAll(
-						ContainSubstring("go1.16"),
+						ContainSubstring("go1.17"),
 						ContainSubstring(`variable value: "some-value"`),
 						ContainSubstring("/workspace contents: []"),
 					),
@@ -123,7 +123,7 @@ func testBuildFlags(t *testing.T, context spec.G, it spec.S) {
 			Eventually(container).Should(
 				Serve(
 					SatisfyAll(
-						ContainSubstring("go1.16"),
+						ContainSubstring("go1.17"),
 						ContainSubstring(`variable value: "env-value"`),
 						ContainSubstring("/workspace contents: []"),
 					),

integration/default_test.go

@@ -85,7 +85,7 @@ func testDefault(t *testing.T, context spec.G, it spec.S) {
 			Eventually(container).Should(
 				Serve(
 					SatisfyAll(
-						ContainSubstring("go1.16"),
+						ContainSubstring("go1.17"),
 						ContainSubstring("/workspace contents: []"),
 					),
 				).OnPort(8080),
@@ -169,7 +169,7 @@ func testDefault(t *testing.T, context spec.G, it spec.S) {
 				Execute(image.ID)
 			Expect(err).NotTo(HaveOccurred())
 
-			Eventually(container).Should(Serve(ContainSubstring("go1.16")).OnPort(8080))
+			Eventually(container).Should(Serve(ContainSubstring("go1.17")).OnPort(8080))
 		})
 	})
 
@@ -220,7 +220,7 @@ func testDefault(t *testing.T, context spec.G, it spec.S) {
 			Eventually(container).Should(
 				Serve(
 					SatisfyAll(
-						ContainSubstring("go1.16"),
+						ContainSubstring("go1.17"),
 						ContainSubstring("/workspace contents: []"),
 					),
 				).OnPort(8080),
@@ -280,7 +280,7 @@ func testDefault(t *testing.T, context spec.G, it spec.S) {
 				Execute(image.ID)
 			Expect(err).NotTo(HaveOccurred())
 
-			Eventually(container).Should(Serve(ContainSubstring("go1.16")).OnPort(8080))
+			Eventually(container).Should(Serve(ContainSubstring("go1.17")).OnPort(8080))
 
 			Expect(logs).To(ContainLines(
 				"  Assigning launch processes:",
@@ -296,7 +296,7 @@ func testDefault(t *testing.T, context spec.G, it spec.S) {
 				Execute(image.ID)
 			Expect(err).NotTo(HaveOccurred())
 
-			Eventually(noReloadContainer).Should(Serve(ContainSubstring("go1.16")).OnPort(8080))
+			Eventually(noReloadContainer).Should(Serve(ContainSubstring("go1.17")).OnPort(8080))
 		})
 	})
 }

integration/import_path_test.go

@@ -75,7 +75,7 @@ func testImportPath(t *testing.T, context spec.G, it spec.S) {
 			Eventually(container).Should(
 				Serve(
 					SatisfyAll(
-						ContainSubstring("go1.16"),
+						ContainSubstring("go1.17"),
 						ContainSubstring("/workspace contents: []"),
 					),
 				).OnPort(8080),

integration/keep_files_test.go

@@ -75,7 +75,7 @@ func testKeepFiles(t *testing.T, context spec.G, it spec.S) {
 			Eventually(container).Should(
 				Serve(
 					SatisfyAll(
-						ContainSubstring("go1.16"),
+						ContainSubstring("go1.17"),
 						ContainSubstring("/workspace contents: [/workspace/assets /workspace/static-file]"),
 						ContainSubstring("file contents: Hello world!"),
 					),

integration/mod_test.go

@@ -71,7 +71,7 @@ func testMod(t *testing.T, context spec.G, it spec.S) {
 				Execute(image.ID)
 			Expect(err).NotTo(HaveOccurred())
 
-			Eventually(container).Should(Serve(ContainSubstring("go1.16")).OnPort(8080))
+			Eventually(container).Should(Serve(ContainSubstring("go1.17")).OnPort(8080))
 		})
 	})
 }

integration/rebuild_test.go

@@ -100,7 +100,6 @@ func testRebuild(t *testing.T, context spec.G, it spec.S) {
 
 			Eventually(container).Should(BeAvailable())
 
-			Expect(secondImage.Buildpacks[1].Layers["targets"].Metadata["built_at"]).To(Equal(firstImage.Buildpacks[1].Layers["targets"].Metadata["built_at"]))
 			Expect(secondImage.Buildpacks[1].Layers["targets"].SHA).To(Equal(firstImage.Buildpacks[1].Layers["targets"].SHA))
 		})
 	})

integration/targets_test.go

@@ -86,7 +86,7 @@ func testTargets(t *testing.T, context spec.G, it spec.S) {
 			Expect(err).NotTo(HaveOccurred())
 			containerIDs[container.ID] = struct{}{}
 
-			Eventually(container).Should(Serve(ContainSubstring("first: go1.16")).OnPort(8080))
+			Eventually(container).Should(Serve(ContainSubstring("first: go1.17")).OnPort(8080))
 
 			Expect(logs).To(ContainLines(
 				"  Assigning launch processes:",
@@ -130,7 +130,7 @@ func testTargets(t *testing.T, context spec.G, it spec.S) {
 			Expect(err).NotTo(HaveOccurred())
 			containerIDs[container.ID] = struct{}{}
 
-			Eventually(container).Should(Serve(ContainSubstring("second: go1.16")).OnPort(8080))
+			Eventually(container).Should(Serve(ContainSubstring("second: go1.17")).OnPort(8080))
 		})
 	})
 }

integration/vendor_test.go

@@ -71,7 +71,7 @@ func testVendor(t *testing.T, context spec.G, it spec.S) {
 				Execute(image.ID)
 			Expect(err).NotTo(HaveOccurred())
 
-			Eventually(container).Should(Serve(ContainSubstring("go1.16")).OnPort(8080))
+			Eventually(container).Should(Serve(ContainSubstring("go1.17")).OnPort(8080))
 		})
 	})
 
@@ -120,7 +120,7 @@ func testVendor(t *testing.T, context spec.G, it spec.S) {
 				Execute(image.ID)
 			Expect(err).NotTo(HaveOccurred())
 
-			Eventually(container).Should(Serve(ContainSubstring("go1.16")).OnPort(8080))
+			Eventually(container).Should(Serve(ContainSubstring("go1.17")).OnPort(8080))
 		})
 	})
 }

run/main.go

@@ -6,7 +6,6 @@ import (
 	gobuild "github.com/paketo-buildpacks/go-build"
 	"github.com/paketo-buildpacks/packit/v2"
 	"github.com/paketo-buildpacks/packit/v2/chronos"
-	"github.com/paketo-buildpacks/packit/v2/fs"
 	"github.com/paketo-buildpacks/packit/v2/pexec"
 	"github.com/paketo-buildpacks/packit/v2/sbom"
 	"github.com/paketo-buildpacks/packit/v2/scribe"
@@ -33,7 +32,6 @@ func main() {
 				emitter,
 				chronos.DefaultClock,
 			),
-			fs.NewChecksumCalculator(),
 			gobuild.NewGoPathManager(os.TempDir()),
 			chronos.DefaultClock,
 			emitter,