Fix creator acceptance test flake (#990)

* Use launch cache when calling SaveAs on caching image

- Failure to use the launch cache will result in slower second builds,
  due to the time it takes to pull layers from the daemon
- Improve creator acceptance test

Signed-off-by: Natalie Arellano <narellano@vmware.com>

* Try to make test less flakey by forcing first build to be slower

Signed-off-by: Natalie Arellano <narellano@vmware.com>

Signed-off-by: Natalie Arellano <narellano@vmware.com>

Author: Natalie Arellano

acceptance/creator_test.go

@@ -183,8 +183,9 @@ func testCreatorFunc(platformAPI string) func(t *testing.T, when spec.G, it spec
 
 			when("multiple builds", func() {
 				var (
-					createFlags []string
-					createArgs  []string
+					createFlags          []string
+					createArgs           []string
+					duration1, duration2 time.Duration
 				)
 
 				it.Before(func() {
@@ -200,6 +201,7 @@ func testCreatorFunc(platformAPI string) func(t *testing.T, when spec.G, it spec
 					createArgs = append([]string{ctrPath(creatorPath)}, createFlags...)
 					createArgs = append(createArgs, imageName)
 
+					startTime := time.Now()
 					// first build
 					output := h.DockerRunAndCopy(t,
 						container1,
@@ -216,6 +218,8 @@ func testCreatorFunc(platformAPI string) func(t *testing.T, when spec.G, it spec
 						)...),
 						h.WithArgs(createArgs...),
 					)
+					duration1 = time.Now().Sub(startTime)
+					t.Logf("First build duration: %s", duration1)
 					h.AssertStringDoesNotContain(t, output, "restored with content")
 					h.AssertPathExists(t, filepath.Join(dirBuild1, "layers", "sbom", "build", "samples_hello-world", "sbom.cdx.json"))
 					h.AssertPathExists(t, filepath.Join(dirBuild1, "layers", "sbom", "build", "samples_hello-world", "some-build-layer", "sbom.cdx.json"))
@@ -258,10 +262,11 @@ func testCreatorFunc(platformAPI string) func(t *testing.T, when spec.G, it spec
 							h.WithArgs(createArgs...),
 						)
 						// check that launch cache was used
-						duration := time.Now().Sub(startTime)
-						t.Logf("Build duration: %s", duration)
-						if duration > 3*time.Second {
-							t.Fatalf("Expected second build to complete in less than 3 seconds; took %s", duration)
+						duration2 = time.Now().Sub(startTime)
+						t.Logf("Second build duration: %s", duration2)
+						if duration2+time.Duration(0.1*float64(time.Second)) >= duration1 {
+							t.Logf("Second build output: %s", output)
+							t.Fatalf("Expected second build to complete 0.1s faster than first build; first build took %s, second build took %s", duration1, duration2)
 						}
 						h.AssertStringContains(t, output, "some-layer.sbom.cdx.json restored with content: {\"key\": \"some-launch-true-bom-content\"}")
 						h.AssertStringContains(t, output, "some-cache-layer.sbom.cdx.json restored with content: {\"key\": \"some-cache-true-bom-content\"}")

acceptance/testdata/creator/container/cnb/buildpacks/samples_hello-world/0.0.1/bin/build

@@ -28,7 +28,15 @@ fi
 
 echo -n "{\"key\": \"some-launch-true-bom-content\"}" > ${layers_dir}/some-layer.sbom.cdx.json
 
-cat <<EOF > "$layers_dir"/some-layer.toml
+if test -f ${layers_dir}/some-layer.toml; then
+  # mimic not downloading new content
+  echo "nop"
+else
+  # mimic downloading new content
+  sleep 1
+fi
+
+cat <<EOF > ${layers_dir}/some-layer.toml
 [types]
   launch = true
 EOF
@@ -42,7 +50,7 @@ fi
 
 echo -n "{\"key\": \"some-cache-true-bom-content\"}" > ${layers_dir}/some-cache-layer.sbom.cdx.json
 
-cat <<EOF > "$layers_dir"/some-cache-layer.toml
+cat <<EOF > ${layers_dir}/some-cache-layer.toml
 [types]
   cache = true
 EOF
@@ -56,7 +64,7 @@ fi
 
 echo -n "{\"key\": \"some-launch-true-cache-true-bom-content\"}" > ${layers_dir}/some-launch-cache-layer.sbom.cdx.json
 
-cat <<EOF > "$layers_dir"/some-launch-cache-layer.toml
+cat <<EOF > ${layers_dir}/some-launch-cache-layer.toml
 [types]
   launch = true
   cache = true
@@ -72,7 +80,7 @@ fi
 
 echo -n "{\"key\": \"some-bom-content\"}" > ${layers_dir}/some-build-layer.sbom.cdx.json
 
-cat <<EOF > "$layers_dir"/some-build-layer.toml
+cat <<EOF > ${layers_dir}/some-build-layer.toml
 [types]
   build = true
 EOF

cache/caching_image.go

@@ -93,6 +93,17 @@ func (c *CachingImage) Save(additionalNames ...string) error {
 	return err
 }
 
+func (c *CachingImage) SaveAs(name string, additionalNames ...string) error {
+	err := c.Image.SaveAs(name, additionalNames...)
+
+	if saveSucceededFor(c.Name(), err) {
+		if err := c.cache.Commit(); err != nil {
+			return errors.Wrap(err, "failed to commit cache")
+		}
+	}
+	return err
+}
+
 func saveSucceededFor(imageName string, err error) bool {
 	if err == nil {
 		return true