Merge pull request #134 from fluxcd/artifact-api-improvements

api/v1alpha1/artifact.go

@@ -17,14 +17,15 @@ limitations under the License.
 package v1alpha1
 
 import (
-	"fmt"
+	"path"
+	"strings"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
-// Artifact represents the output of a source synchronisation
+// Artifact represents the output of a source synchronisation.
 type Artifact struct {
-	// Path is the local file path of this artifact.
+	// Path is the relative file path of this artifact.
 	// +required
 	Path string `json:"path"`
 
@@ -32,20 +33,31 @@ type Artifact struct {
 	// +required
 	URL string `json:"url"`
 
-	// Revision is a human readable identifier traceable in the origin source system.
+	// Revision is a human readable identifier traceable in the origin
-	// It can be a commit sha, git tag, a helm index timestamp,
+	// source system. It can be a Git commit sha, Git tag, a Helm index
-	// a helm chart version, a checksum, etc.
+	// timestamp, a Helm chart version, etc.
 	// +optional
 	Revision string `json:"revision"`
 
+	// Checksum is the SHA1 checksum of the artifact.
+	// +optional
+	Checksum string `json:"checksum"`
+
 	// LastUpdateTime is the timestamp corresponding to the last
 	// update of this artifact.
 	// +required
 	LastUpdateTime metav1.Time `json:"lastUpdateTime,omitempty"`
 }
 
-// ArtifactPath returns the artifact path in the form of
+// ArtifactDir returns the artifact dir path in the form of
-// <source-kind>/<source-namespace>/<source-name>/<artifact-filename>
+// <source-kind>/<source-namespace>/<source-name>.
-func ArtifactPath(kind, namespace, name, filename string) string {
+func ArtifactDir(kind, namespace, name string) string {
-	return fmt.Sprintf("%s/%s/%s/%s", kind, namespace, name, filename)
+	kind = strings.ToLower(kind)
+	return path.Join(kind, namespace, name)
+}
+
+// ArtifactPath returns the artifact path in the form of
+// <source-kind>/<source-namespace>/<source-name>/<artifact-filename>.
+func ArtifactPath(kind, namespace, name, filename string) string {
+	return path.Join(ArtifactDir(kind, namespace, name), filename)
 }

api/v1alpha1/source.go

@@ -1,6 +1,8 @@
 package v1alpha1
 
-import metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
 
 // Source interface must be supported by all API types.
 // +k8s:deepcopy-gen=false

config/crd/bases/source.toolkit.fluxcd.io_gitrepositories.yaml

@@ -129,18 +129,21 @@ spec:
                 description: Artifact represents the output of the last successful
                   repository sync.
                 properties:
+                  checksum:
+                    description: Checksum is the SHA1 checksum of the artifact.
+                    type: string
                   lastUpdateTime:
                     description: LastUpdateTime is the timestamp corresponding to
                       the last update of this artifact.
                     format: date-time
                     type: string
                   path:
-                    description: Path is the local file path of this artifact.
+                    description: Path is the relative file path of this artifact.
                     type: string
                   revision:
                     description: Revision is a human readable identifier traceable
-                      in the origin source system. It can be a commit sha, git tag,
+                      in the origin source system. It can be a Git commit sha, Git
-                      a helm index timestamp, a helm chart version, a checksum, etc.
+                      tag, a Helm index timestamp, a Helm chart version, etc.
                     type: string
                   url:
                     description: URL is the HTTP address of this artifact.

config/crd/bases/source.toolkit.fluxcd.io_helmcharts.yaml

@@ -101,18 +101,21 @@ spec:
                 description: Artifact represents the output of the last successful
                   chart sync.
                 properties:
+                  checksum:
+                    description: Checksum is the SHA1 checksum of the artifact.
+                    type: string
                   lastUpdateTime:
                     description: LastUpdateTime is the timestamp corresponding to
                       the last update of this artifact.
                     format: date-time
                     type: string
                   path:
-                    description: Path is the local file path of this artifact.
+                    description: Path is the relative file path of this artifact.
                     type: string
                   revision:
                     description: Revision is a human readable identifier traceable
-                      in the origin source system. It can be a commit sha, git tag,
+                      in the origin source system. It can be a Git commit sha, Git
-                      a helm index timestamp, a helm chart version, a checksum, etc.
+                      tag, a Helm index timestamp, a Helm chart version, etc.
                     type: string
                   url:
                     description: URL is the HTTP address of this artifact.

config/crd/bases/source.toolkit.fluxcd.io_helmrepositories.yaml

@@ -81,18 +81,21 @@ spec:
                 description: Artifact represents the output of the last successful
                   repository sync.
                 properties:
+                  checksum:
+                    description: Checksum is the SHA1 checksum of the artifact.
+                    type: string
                   lastUpdateTime:
                     description: LastUpdateTime is the timestamp corresponding to
                       the last update of this artifact.
                     format: date-time
                     type: string
                   path:
-                    description: Path is the local file path of this artifact.
+                    description: Path is the relative file path of this artifact.
                     type: string
                   revision:
                     description: Revision is a human readable identifier traceable
-                      in the origin source system. It can be a commit sha, git tag,
+                      in the origin source system. It can be a Git commit sha, Git
-                      a helm index timestamp, a helm chart version, a checksum, etc.
+                      tag, a Helm index timestamp, a Helm chart version, etc.
                     type: string
                   url:
                     description: URL is the HTTP address of this artifact.

controllers/gitrepository_controller.go

@@ -212,8 +212,10 @@ func (r *GitRepositoryReconciler) reconcile(ctx context.Context, repository sour
 		}
 	}
 
+	// TODO(hidde): implement checksum when https://github.com/fluxcd/source-controller/pull/133
+	//   has been merged.
 	artifact := r.Storage.ArtifactFor(repository.Kind, repository.ObjectMeta.GetObjectMeta(),
-		fmt.Sprintf("%s.tar.gz", commit.Hash.String()), revision)
+		fmt.Sprintf("%s.tar.gz", commit.Hash.String()), revision, "")
 
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
@@ -300,10 +302,10 @@ func (r *GitRepositoryReconciler) verify(ctx context.Context, publicKeySecret ty
 // gc performs a garbage collection on all but current artifacts of
 // the given repository.
 func (r *GitRepositoryReconciler) gc(repository sourcev1.GitRepository, all bool) error {
+	if all {
+		return r.Storage.RemoveAll(r.Storage.ArtifactFor(repository.Kind, repository.GetObjectMeta(), "", "", ""))
+	}
 	if repository.Status.Artifact != nil {
-		if all {
-			return r.Storage.RemoveAll(*repository.Status.Artifact)
-		}
 		return r.Storage.RemoveAllButCurrent(*repository.Status.Artifact)
 	}
 	return nil

controllers/helmchart_controller.go

@@ -188,7 +188,8 @@ func (r *HelmChartReconciler) SetupWithManagerAndOptions(mgr ctrl.Manager, opts
 
 func (r *HelmChartReconciler) reconcileFromHelmRepository(ctx context.Context,
 	repository sourcev1.HelmRepository, chart sourcev1.HelmChart) (sourcev1.HelmChart, error) {
-	cv, err := helm.GetDownloadableChartVersionFromIndex(repository.Status.Artifact.Path, chart.Spec.Chart, chart.Spec.Version)
+	cv, err := helm.GetDownloadableChartVersionFromIndex(r.Storage.LocalPath(*repository.GetArtifact()),
+		chart.Spec.Chart, chart.Spec.Version)
 	if err != nil {
 		return sourcev1.HelmChartNotReady(chart, sourcev1.ChartPullFailedReason, err.Error()), err
 	}
@@ -260,7 +261,7 @@ func (r *HelmChartReconciler) reconcileFromHelmRepository(ctx context.Context,
 
 	sum := r.Storage.Checksum(chartBytes)
 	artifact := r.Storage.ArtifactFor(chart.Kind, chart.GetObjectMeta(),
-		fmt.Sprintf("%s-%s-%s.tgz", cv.Name, cv.Version, sum), cv.Version)
+		fmt.Sprintf("%s-%s-%s.tgz", cv.Name, cv.Version, sum), cv.Version, sum)
 
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
@@ -333,7 +334,7 @@ func (r *HelmChartReconciler) reconcileFromGitRepository(ctx context.Context,
 	defer os.RemoveAll(tmpDir)
 
 	// open file
-	f, err := os.Open(repository.GetArtifact().Path)
+	f, err := os.Open(r.Storage.LocalPath(*repository.GetArtifact()))
 	if err != nil {
 		err = fmt.Errorf("artifact open error: %w", err)
 		return sourcev1.HelmChartNotReady(chart, sourcev1.StorageOperationFailedReason, err.Error()), err
@@ -364,8 +365,10 @@ func (r *HelmChartReconciler) reconcileFromGitRepository(ctx context.Context,
 		return chart, nil
 	}
 
+	// TODO(hidde): implement checksum when https://github.com/fluxcd/source-controller/pull/133
+	//   has been merged.
 	artifact := r.Storage.ArtifactFor(chart.Kind, chart.ObjectMeta.GetObjectMeta(),
-		fmt.Sprintf("%s-%s.tgz", chartMetadata.Name, chartMetadata.Version), chartMetadata.Version)
+		fmt.Sprintf("%s-%s.tgz", chartMetadata.Name, chartMetadata.Version), chartMetadata.Version, "")
 
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
@@ -384,7 +387,7 @@ func (r *HelmChartReconciler) reconcileFromGitRepository(ctx context.Context,
 
 	// package chart
 	pkg := action.NewPackage()
-	pkg.Destination = filepath.Dir(artifact.Path)
+	pkg.Destination = filepath.Dir(r.Storage.LocalPath(artifact))
 	_, err = pkg.Run(chartPath, nil)
 	if err != nil {
 		err = fmt.Errorf("chart package error: %w", err)
@@ -432,10 +435,10 @@ func (r *HelmChartReconciler) getGitRepositoryWithArtifact(ctx context.Context,
 // gc performs a garbage collection on all but current artifacts of
 // the given chart.
 func (r *HelmChartReconciler) gc(chart sourcev1.HelmChart, all bool) error {
+	if all {
+		return r.Storage.RemoveAll(r.Storage.ArtifactFor(chart.Kind, chart.GetObjectMeta(), "", "", ""))
+	}
 	if chart.Status.Artifact != nil {
-		if all {
-			return r.Storage.RemoveAll(*chart.Status.Artifact)
-		}
 		return r.Storage.RemoveAllButCurrent(*chart.Status.Artifact)
 	}
 	return nil

controllers/helmrepository_controller.go

@@ -229,7 +229,7 @@ func (r *HelmRepositoryReconciler) reconcile(ctx context.Context, repository sou
 
 	sum := r.Storage.Checksum(index)
 	artifact := r.Storage.ArtifactFor(repository.Kind, repository.ObjectMeta.GetObjectMeta(),
-		fmt.Sprintf("index-%s.yaml", sum), sum)
+		fmt.Sprintf("index-%s.yaml", sum), i.Generated.Format(time.RFC3339Nano), sum)
 
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
@@ -294,10 +294,10 @@ func (r *HelmRepositoryReconciler) shouldResetStatus(repository sourcev1.HelmRep
 // gc performs a garbage collection on all but current artifacts of
 // the given repository.
 func (r *HelmRepositoryReconciler) gc(repository sourcev1.HelmRepository, all bool) error {
+	if all {
+		return r.Storage.RemoveAll(r.Storage.ArtifactFor(repository.Kind, repository.GetObjectMeta(), "", "", ""))
+	}
 	if repository.Status.Artifact != nil {
-		if all {
-			return r.Storage.RemoveAll(*repository.Status.Artifact)
-		}
 		return r.Storage.RemoveAllButCurrent(*repository.Status.Artifact)
 	}
 	return nil

controllers/storage.go

@@ -69,9 +69,8 @@ func NewStorage(basePath string, hostname string, timeout time.Duration) (*Stora
 	}, nil
 }
 
-// ArtifactFor returns an artifact for the given Kubernetes object
+// ArtifactFor returns an artifact for the v1alpha1.Source.
-func (s *Storage) ArtifactFor(kind string, metadata metav1.Object, fileName, revision string) sourcev1.Artifact {
+func (s *Storage) ArtifactFor(kind string, metadata metav1.Object, fileName, revision, checksum string) sourcev1.Artifact {
-	kind = strings.ToLower(kind)
 	path := sourcev1.ArtifactPath(kind, metadata.GetNamespace(), metadata.GetName(), fileName)
 	localPath := filepath.Join(s.BasePath, path)
 	url := fmt.Sprintf("http://%s/%s", s.Hostname, path)
@@ -80,25 +79,27 @@ func (s *Storage) ArtifactFor(kind string, metadata metav1.Object, fileName, rev
 		Path:           localPath,
 		URL:            url,
 		Revision:       revision,
+		Checksum:       checksum,
 		LastUpdateTime: metav1.Now(),
 	}
 }
 
-// MkdirAll calls os.MkdirAll for the given artifact base dir
+// MkdirAll calls os.MkdirAll for the given v1alpha1.Artifact base dir.
 func (s *Storage) MkdirAll(artifact sourcev1.Artifact) error {
-	dir := filepath.Dir(artifact.Path)
+	dir := filepath.Dir(s.LocalPath(artifact))
 	return os.MkdirAll(dir, 0777)
 }
 
-// RemoveAll calls os.RemoveAll for the given artifact base dir
+// RemoveAll calls os.RemoveAll for the given v1alpha1.Artifact base dir.
 func (s *Storage) RemoveAll(artifact sourcev1.Artifact) error {
-	dir := filepath.Dir(artifact.Path)
+	dir := filepath.Dir(s.LocalPath(artifact))
 	return os.RemoveAll(dir)
 }
 
 // RemoveAllButCurrent removes all files for the given artifact base dir excluding the current one
 func (s *Storage) RemoveAllButCurrent(artifact sourcev1.Artifact) error {
-	dir := filepath.Dir(artifact.Path)
+	localPath := s.LocalPath(artifact)
+	dir := filepath.Dir(localPath)
 	var errors []string
 	_ = filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
 		if err != nil {
@@ -106,7 +107,7 @@ func (s *Storage) RemoveAllButCurrent(artifact sourcev1.Artifact) error {
 			return nil
 		}
 
-		if path != artifact.Path && !info.IsDir() && info.Mode()&os.ModeSymlink != os.ModeSymlink {
+		if path != localPath && !info.IsDir() && info.Mode()&os.ModeSymlink != os.ModeSymlink {
 			if err := os.Remove(path); err != nil {
 				errors = append(errors, info.Name())
 			}
@@ -123,7 +124,7 @@ func (s *Storage) RemoveAllButCurrent(artifact sourcev1.Artifact) error {
 // ArtifactExist returns a boolean indicating whether the artifact exists in storage and is a
 // regular file.
 func (s *Storage) ArtifactExist(artifact sourcev1.Artifact) bool {
-	fi, err := os.Lstat(artifact.Path)
+	fi, err := os.Lstat(s.LocalPath(artifact))
 	if err != nil {
 		return false
 	}
@@ -144,7 +145,7 @@ func (s *Storage) Archive(artifact sourcev1.Artifact, dir string, spec sourcev1.
 
 	matcher := gitignore.NewMatcher(ps)
 
-	gzFile, err := os.Create(artifact.Path)
+	gzFile, err := os.Create(s.LocalPath(artifact))
 	if err != nil {
 		return err
 	}
@@ -205,20 +206,22 @@ func (s *Storage) Archive(artifact sourcev1.Artifact, dir string, spec sourcev1.
 
 // WriteFile writes the given bytes to the artifact path if the checksum differs
 func (s *Storage) WriteFile(artifact sourcev1.Artifact, data []byte) error {
+	localPath := s.LocalPath(artifact)
 	sum := s.Checksum(data)
-	if file, err := os.Stat(artifact.Path); !os.IsNotExist(err) && !file.IsDir() {
+	if file, err := os.Stat(localPath); !os.IsNotExist(err) && !file.IsDir() {
-		if fb, err := ioutil.ReadFile(artifact.Path); err == nil && sum == s.Checksum(fb) {
+		if fb, err := ioutil.ReadFile(localPath); err == nil && sum == s.Checksum(fb) {
 			return nil
 		}
 	}
 
-	return ioutil.WriteFile(artifact.Path, data, 0644)
+	return ioutil.WriteFile(localPath, data, 0644)
 }
 
 // Symlink creates or updates a symbolic link for the given artifact
-// and returns the URL for the symlink
+// and returns the URL for the symlink.
 func (s *Storage) Symlink(artifact sourcev1.Artifact, linkName string) (string, error) {
-	dir := filepath.Dir(artifact.Path)
+	localPath := s.LocalPath(artifact)
+	dir := filepath.Dir(localPath)
 	link := filepath.Join(dir, linkName)
 	tmpLink := link + ".tmp"
 
@@ -226,7 +229,7 @@ func (s *Storage) Symlink(artifact sourcev1.Artifact, linkName string) (string,
 		return "", err
 	}
 
-	if err := os.Symlink(artifact.Path, tmpLink); err != nil {
+	if err := os.Symlink(localPath, tmpLink); err != nil {
 		return "", err
 	}
 
@@ -246,11 +249,20 @@ func (s *Storage) Checksum(b []byte) string {
 
 // Lock creates a file lock for the given artifact
 func (s *Storage) Lock(artifact sourcev1.Artifact) (unlock func(), err error) {
-	lockFile := artifact.Path + ".lock"
+	lockFile := s.LocalPath(artifact) + ".lock"
 	mutex := lockedfile.MutexAt(lockFile)
 	return mutex.Lock()
 }
 
+// LocalPath returns the local path of the given artifact (that is: relative to
+// the Storage.BasePath).
+func (s *Storage) LocalPath(artifact sourcev1.Artifact) string {
+	if artifact.Path == "" {
+		return ""
+	}
+	return filepath.Join(s.BasePath, artifact.Path)
+}
+
 func getPatterns(reader io.Reader, path []string) []gitignore.Pattern {
 	var ps []gitignore.Pattern
 	scanner := bufio.NewScanner(reader)

controllers/storage_test.go

@@ -113,9 +113,9 @@ func walkTar(tarFile string, match string) (bool, error) {
 	return false, nil
 }
 
-func testPatterns(t *testing.T, artifact sourcev1.Artifact, table ignoreMap) {
+func testPatterns(t *testing.T, dir string, artifact sourcev1.Artifact, table ignoreMap) {
 	for name, expected := range table {
-		res, err := walkTar(artifact.Path, name)
+		res, err := walkTar(filepath.Join(dir, artifact.Path), name)
 		if err != nil {
 			t.Fatalf("while reading tarball: %v", err)
 		}
@@ -130,13 +130,7 @@ func testPatterns(t *testing.T, artifact sourcev1.Artifact, table ignoreMap) {
 	}
 }
 
-func createArchive(t *testing.T, filenames []string, sourceIgnore string, spec sourcev1.GitRepositorySpec) sourcev1.Artifact {
+func createArchive(t *testing.T, dir string, filenames []string, sourceIgnore string, spec sourcev1.GitRepositorySpec) sourcev1.Artifact {
-	dir, err := createStoragePath()
-	if err != nil {
-		t.Fatal(err)
-	}
-	t.Cleanup(cleanupStoragePath(dir))
-
 	storage, err := NewStorage(dir, "hostname", time.Minute)
 	if err != nil {
 		t.Fatalf("Error while bootstrapping storage: %v", err)
@@ -197,7 +191,13 @@ func TestArchiveBasic(t *testing.T) {
 		".gitignore": false,
 	}
 
-	testPatterns(t, createArchive(t, []string{"README.md", ".gitignore"}, "", sourcev1.GitRepositorySpec{}), table)
+	dir, err := createStoragePath()
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(cleanupStoragePath(dir))
+
+	testPatterns(t, dir, createArchive(t, dir, []string{"README.md", ".gitignore"}, "", sourcev1.GitRepositorySpec{}), table)
 }
 
 func TestArchiveIgnore(t *testing.T) {
@@ -221,8 +221,14 @@ func TestArchiveIgnore(t *testing.T) {
 		table[item] = false
 	}
 
+	dir, err := createStoragePath()
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(cleanupStoragePath(dir))
+
 	t.Run("automatically ignored files", func(t *testing.T) {
-		testPatterns(t, createArchive(t, filenames, "", sourcev1.GitRepositorySpec{}), table)
+		testPatterns(t, dir, createArchive(t, dir, filenames, "", sourcev1.GitRepositorySpec{}), table)
 	})
 
 	table = ignoreMap{}
@@ -231,7 +237,7 @@ func TestArchiveIgnore(t *testing.T) {
 	}
 
 	t.Run("only vcs ignored files", func(t *testing.T) {
-		testPatterns(t, createArchive(t, filenames, "", sourcev1.GitRepositorySpec{Ignore: stringPtr("")}), table)
+		testPatterns(t, dir, createArchive(t, dir, filenames, "", sourcev1.GitRepositorySpec{Ignore: stringPtr("")}), table)
 	})
 
 	filenames = append(filenames, "test.txt")
@@ -239,7 +245,7 @@ func TestArchiveIgnore(t *testing.T) {
 	sourceIgnoreFile := "*.txt"
 
 	t.Run("sourceignore injected via CRD", func(t *testing.T) {
-		testPatterns(t, createArchive(t, filenames, "", sourcev1.GitRepositorySpec{Ignore: stringPtr(sourceIgnoreFile)}), table)
+		testPatterns(t, dir, createArchive(t, dir, filenames, "", sourcev1.GitRepositorySpec{Ignore: stringPtr(sourceIgnoreFile)}), table)
 	})
 
 	table = ignoreMap{}
@@ -248,7 +254,7 @@ func TestArchiveIgnore(t *testing.T) {
 	}
 
 	t.Run("sourceignore injected via filename", func(t *testing.T) {
-		testPatterns(t, createArchive(t, filenames, sourceIgnoreFile, sourcev1.GitRepositorySpec{}), table)
+		testPatterns(t, dir, createArchive(t, dir, filenames, sourceIgnoreFile, sourcev1.GitRepositorySpec{}), table)
 	})
 }
 

docs/api/source.md

@@ -458,7 +458,7 @@ HelmRepositoryStatus
 <a href="#source.toolkit.fluxcd.io/v1alpha1.HelmChartStatus">HelmChartStatus</a>, 
 <a href="#source.toolkit.fluxcd.io/v1alpha1.HelmRepositoryStatus">HelmRepositoryStatus</a>)
 </p>
-<p>Artifact represents the output of a source synchronisation</p>
+<p>Artifact represents the output of a source synchronisation.</p>
 <div class="md-typeset__scrollwrap">
 <div class="md-typeset__table">
 <table>
@@ -477,7 +477,7 @@ string
 </em>
 </td>
 <td>
-<p>Path is the local file path of this artifact.</p>
+<p>Path is the relative file path of this artifact.</p>
 </td>
 </tr>
 <tr>
@@ -500,9 +500,21 @@ string
 </td>
 <td>
 <em>(Optional)</em>
-<p>Revision is a human readable identifier traceable in the origin source system.
+<p>Revision is a human readable identifier traceable in the origin
-It can be a commit sha, git tag, a helm index timestamp,
+source system. It can be a Git commit sha, Git tag, a Helm index
-a helm chart version, a checksum, etc.</p>
+timestamp, a Helm chart version, etc.</p>
+</td>
+</tr>
+<tr>
+<td>
+<code>checksum</code><br>
+<em>
+string
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>Checksum is the SHA1 checksum of the artifact.</p>
 </td>
 </tr>
 <tr>

docs/spec/v1alpha1/common.md

@@ -54,9 +54,9 @@ kubectl annotate --overwrite gitrepository/podinfo fluxcd.io/reconcileAt="$(date
 Source objects should contain a status sub-resource that embeds an artifact object:
 
 ```go
-// Artifact represents the output of a source synchronisation
+// Artifact represents the output of a source synchronisation.
 type Artifact struct {
-	// Path is the local file path of this artifact.
+	// Path is the relative file path of this artifact.
 	// +required
 	Path string `json:"path"`
 
@@ -64,12 +64,16 @@ type Artifact struct {
 	// +required
 	URL string `json:"url"`
 
-	// Revision is a human readable identifier traceable in the origin source system.
+	// Revision is a human readable identifier traceable in the origin
-	// It can be a commit sha, git tag, a helm index timestamp,
+	// source system. It can be a Git commit sha, Git tag, a Helm index
-	// a helm chart version, a checksum, etc.
+	// timestamp, a Helm chart version, etc.
 	// +optional
 	Revision string `json:"revision"`
 
+	// Checksum is the SHA1 checksum of the artifact.
+	// +optional
+	Checksum string `json:"checksum"`
+
 	// LastUpdateTime is the timestamp corresponding to the last
 	// update of this artifact.
 	// +required