fix(digest): check container image info for nil (#1027)

internal/actions/mocks/container.go

@@ -43,6 +43,11 @@ func CreateMockContainer(id string, name string, image string, created time.Time
 
 // CreateMockContainerWithImageInfo should only be used for testing
 func CreateMockContainerWithImageInfo(id string, name string, image string, created time.Time, imageInfo types.ImageInspect) container.Container {
+	return CreateMockContainerWithImageInfoP(id, name, image, created, &imageInfo)
+}
+
+// CreateMockContainerWithImageInfoP should only be used for testing
+func CreateMockContainerWithImageInfoP(id string, name string, image string, created time.Time, imageInfo *types.ImageInspect) container.Container {
 	content := types.ContainerJSON{
 		ContainerJSONBase: &types.ContainerJSONBase{
 			ID:      id,
@@ -57,7 +62,7 @@ func CreateMockContainerWithImageInfo(id string, name string, image string, crea
 	}
 	return *container.NewContainer(
 		&content,
-		&imageInfo,
+		imageInfo,
 	)
 }
 

pkg/registry/digest/digest.go

@@ -22,6 +22,10 @@ const ContentDigestHeader = "Docker-Content-Digest"
 
 // CompareDigest ...
 func CompareDigest(container types.Container, registryAuth string) (bool, error) {
+	if !container.HasImageInfo() {
+		return false, errors.New("container image info missing")
+	}
+	
 	var digest string
 
 	registryAuth = TransformAuth(registryAuth)

pkg/registry/digest/digest_test.go

@@ -59,6 +59,8 @@ var _ = Describe("Digests", func() {
 		mockCreated,
 		mockDigest)
 
+	mockContainerNoImage := mocks.CreateMockContainerWithImageInfoP(mockId, mockName, mockImage, mockCreated, nil)
+
 	When("a digest comparison is done", func() {
 		It("should return true if digests match",
 			SkipIfCredentialsEmpty(GHCRCredentials, func() {
@@ -75,6 +77,11 @@ var _ = Describe("Digests", func() {
 		It("should return an error if the registry isn't available", func() {
 
 		})
+		It("should return an error when container contains no image info", func() {
+			matches, err := digest.CompareDigest(mockContainerNoImage, `user:pass`)
+			Expect(err).To(HaveOccurred())
+			Expect(matches).To(Equal(false))
+		})
 	})
 	When("using different registries", func() {
 		It("should work with DockerHub",