Allow artifact add to override org.opencontainers.image.title annotation

docs/source/markdown/podman-artifact-add.1.md.in

@@ -21,7 +21,8 @@ the `--append` option, the original creation timestamp is preserved.
 
 @@option annotation.manifest
 
-Note: Set annotations for each file being added.
+Note: Set annotations for each file being added. The annotation "org.opencontainers.image.title" is used
+to name the layer when mounted into a container, this title must be unigue for each artifact layer.
 
 #### **--append**, **-a**
 
@@ -78,6 +79,13 @@ Add files to an existing OCI artifact
 $ podman artifact add --append quay.io/myimage/myartifact:latest /home/user/config.yaml
 ```
 
+Create artifact with the layer title name being replaced, and then mount into a container.
+
+```
+podman artifact add --annotation org.opencontainers.image.title=smollm2 quay.io/myreg/smollm2:latest blobs/sha256-4d2396b16114669389d7555c15a1592aad584750310f648edad5ca8c4eccda17
+podman run --mount type=artifact,source=quay.io/myreg/smollm2:latest,destination=/mnt fedora ls -l /mnt
+smollm2
+```
 
 ## SEE ALSO
 **[podman(1)](podman.1.md)**, **[podman-artifact(1)](podman-artifact.1.md)**

pkg/libartifact/store/store.go

@@ -221,13 +221,6 @@ func (as ArtifactStore) Add(ctx context.Context, dest string, artifactBlobs []en
 		return nil, errors.New("append option is not compatible with type option")
 	}
 
-	// currently we don't allow override of the filename ; if a user requirement emerges,
-	// we could seemingly accommodate but broadens possibilities of something bad happening
-	// for things like `artifact extract`
-	if _, hasTitle := options.Annotations[specV1.AnnotationTitle]; hasTitle {
-		return nil, fmt.Errorf("cannot override filename with %s annotation", specV1.AnnotationTitle)
-	}
-
 	locked := true
 	as.lock.Lock()
 	defer func() {
@@ -320,7 +313,17 @@ func (as ArtifactStore) Add(ctx context.Context, dest string, artifactBlobs []en
 		}
 
 		annotations := maps.Clone(options.Annotations)
-		annotations[specV1.AnnotationTitle] = artifactBlob.FileName
+		if title, ok := annotations[specV1.AnnotationTitle]; ok {
+			// Verify a duplicate AnnotationTitle is not in use in a different layer.
+			for _, layer := range artifactManifest.Layers {
+				if title == layer.Annotations[specV1.AnnotationTitle] {
+					return nil, fmt.Errorf("duplicate layers %s labels within an artifact not allowed", specV1.AnnotationTitle)
+				}
+			}
+		} else {
+			// Only override if the user did not specify the Title
+			annotations[specV1.AnnotationTitle] = artifactBlob.FileName
+		}
 
 		newLayer := specV1.Descriptor{
 			MediaType:   options.FileMIMEType,
@@ -472,6 +475,11 @@ func (as ArtifactStore) BlobMountPaths(ctx context.Context, nameOrDigest string,
 	mountPaths := make([]libartTypes.BlobMountPath, 0, len(arty.Manifest.Layers))
 	for _, l := range arty.Manifest.Layers {
 		title := l.Annotations[specV1.AnnotationTitle]
+		for _, mp := range mountPaths {
+			if title == mp.Name {
+				return nil, fmt.Errorf("annotation %q:%q is used in multiple different layers within artifact", specV1.AnnotationTitle, title)
+			}
+		}
 		filename, err := generateArtifactBlobName(title, l.Digest)
 		if err != nil {
 			return nil, err

pkg/machine/ocipull/ociartifact.go

@@ -27,7 +27,7 @@ const (
 	artifactRegistry     = "quay.io"
 	artifactRepo         = "podman"
 	artifactImageName    = "machine-os"
-	artifactOriginalName = "org.opencontainers.image.title"
+	artifactOriginalName = specV1.AnnotationTitle
 	machineOS            = "linux"
 )
 

test/e2e/artifact_test.go

@@ -14,6 +14,7 @@ import (
 	"github.com/containers/podman/v5/utils"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
+	imgspec "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
 const (
@@ -99,8 +100,12 @@ var _ = Describe("Podman artifact", func() {
 	It("podman artifact add with options", func() {
 		yamlType := "text/yaml"
 		artifact1Name := "localhost/test/artifact1"
+		artifact2Name := "localhost/test/artifact2"
+		artifact3Name := "localhost/test/artifact3"
 		artifact1File, err := createArtifactFile(1024)
 		Expect(err).ToNot(HaveOccurred())
+		artifact2File, err := createArtifactFile(1024)
+		Expect(err).ToNot(HaveOccurred())
 
 		artifactType := "octet/foobar"
 		annotation1 := "color=blue"
@@ -115,9 +120,26 @@ var _ = Describe("Podman artifact", func() {
 		Expect(a.Manifest.Layers[0].Annotations["flavor"]).To(Equal("lemon"))
 		Expect(a.Manifest.Layers[0].MediaType).To(Equal(yamlType))
 
-		failSession := podmanTest.Podman([]string{"artifact", "add", "--annotation", "org.opencontainers.image.title=foobar", "foobar", artifact1File})
+		title := RandomString(12)
+		annotation3 := fmt.Sprintf("%s=%s", imgspec.AnnotationTitle, title)
+		podmanTest.PodmanExitCleanly("artifact", "add", "--annotation", annotation3, artifact2Name, artifact1File)
+		a = podmanTest.InspectArtifact(artifact2Name)
+		Expect(a.Manifest.Layers[0].Annotations[imgspec.AnnotationTitle]).To(Equal(title))
+
+		failSession := podmanTest.Podman([]string{"artifact", "add", "--append", "--annotation", annotation3, artifact2Name, artifact2File})
 		failSession.WaitWithDefaultTimeout()
-		Expect(failSession).Should(ExitWithError(125, "Error: cannot override filename with org.opencontainers.image.title annotation"))
+		Expect(failSession).Should(ExitWithError(125, "Error: duplicate layers org.opencontainers.image.title labels within an artifact not allowed"))
+
+		title = RandomString(12)
+		annotation3 = fmt.Sprintf("%s=%s", imgspec.AnnotationTitle, title)
+		podmanTest.PodmanExitCleanly("artifact", "add", "--append", "--annotation", annotation3, artifact2Name, artifact2File)
+		a = podmanTest.InspectArtifact(artifact2Name)
+		Expect(a.Manifest.Layers[1].Annotations[imgspec.AnnotationTitle]).To(Equal(title))
+
+		failSession = podmanTest.Podman([]string{"artifact", "add", "--annotation", annotation3, artifact3Name, artifact1File, artifact2File})
+		failSession.WaitWithDefaultTimeout()
+		Expect(failSession).Should(ExitWithError(125, "Error: duplicate layers org.opencontainers.image.title labels within an artifact not allowed"))
+
 	})
 
 	It("podman artifact add multiple", func() {
@@ -480,9 +502,9 @@ var _ = Describe("Podman artifact", func() {
 		Expect(a.Manifest.Layers).To(HaveLen(3))
 
 		for _, l := range a.Manifest.Layers {
-			layersNames[l.Annotations["org.opencontainers.image.title"]] += 1
+			layersNames[l.Annotations[imgspec.AnnotationTitle]] += 1
 
-			if l.Annotations["org.opencontainers.image.title"] == filepath.Base(artifact3File) {
+			if l.Annotations[imgspec.AnnotationTitle] == filepath.Base(artifact3File) {
 				Expect(l.Annotations["color"]).To(Equal("blue"))
 			} else {
 				Expect(l.Annotations).To(HaveLen(1))