artifact mount: add new name option to specify filename

An artifact without the title annoation just gets the digest as name
which is less than ideal. While it is a decent default to avoid
conflicts users would like to configure the name.

With the name=abc option we will call the file abc in case of a signle
artifact and otherwise we use abc-x where x is the layer index starting
at 0 to avoid conflicts.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

docs/source/markdown/options/mount.md

@@ -32,6 +32,12 @@ Options specific to type=**artifact**:
 - *title*: If the artifact source contains multiple blobs a title can be set
   which is compared against `org.opencontainers.image.title` annotation.
 
+- *name*: This can be used to overwrite the filename we use inside the container
+  for mounting. On a single blob artifact the name is used as is if *dst* is a
+  directory and otherwise ignored. With a multi blob artifact the name will be
+  used with an index suffix `<name>-x` where x is the layer index in the artifact
+  starting with 0.
+
 The *src* argument contains the name of the artifact, which must already exist locally.
 The *dst* argument contains the target path, if the path in the container is a
 directory the blob title (`org.opencontainers.image.title` annotation) will be used as

libpod/container.go

@@ -300,6 +300,11 @@ type ContainerArtifactVolume struct {
 	// the title annotation exist.
 	// Optional. Conflicts with Title.
 	Digest string `json:"digest"`
+	// Name is the name that should be used for the path inside the container. When a single blob
+	// is mounted the name is used as is. If multiple blobs are mounted then mount them as
+	// "<name>-x" where x is a 0 indexed integer based on the layer order.
+	// Optional.
+	Name string `json:"name,omitempty"`
 }
 
 // ContainerSecret is a secret that is mounted in a container

libpod/container_internal_common.go

@@ -564,12 +564,21 @@ func (c *Container) generateSpec(ctx context.Context) (s *spec.Spec, cleanupFunc
 				return nil, nil, fmt.Errorf("artifact %q contains more than one blob and container path %q is a file", artifactMount.Source, artifactMount.Dest)
 			}
 
-			for _, path := range paths {
+			for i, path := range paths {
 				var dest string
 				if destIsFile {
 					dest = artifactMount.Dest
 				} else {
-					dest = filepath.Join(artifactMount.Dest, path.Name)
+					var filename string
+					if artifactMount.Name != "" {
+						filename = artifactMount.Name
+						if len(paths) > 1 {
+							filename += "-" + strconv.Itoa(i)
+						}
+					} else {
+						filename = path.Name
+					}
+					dest = filepath.Join(artifactMount.Dest, filename)
 				}
 
 				logrus.Debugf("Mounting artifact %q in container %s, mount blob %q to %q", artifactMount.Source, c.ID(), path.SourcePath, dest)

pkg/specgen/generate/container_create.go

@@ -515,6 +515,7 @@ func createContainerOptions(rt *libpod.Runtime, s *specgen.SpecGenerator, pod *l
 				Source: v.Source,
 				Digest: v.Digest,
 				Title:  v.Title,
+				Name:   v.Name,
 			})
 		}
 		options = append(options, libpod.WithArtifactVolumes(vols))

pkg/specgen/volumes.go

@@ -78,6 +78,11 @@ type ArtifactVolume struct {
 	// the title annotation exist.
 	// Optional. Conflicts with Title.
 	Digest string `json:"digest,omitempty"`
+	// Name is the name that should be used for the path inside the container. When a single blob
+	// is mounted the name is used as is. If multiple blobs are mounted then mount them as
+	// "<name>-x" where x is a 0 indexed integer based on the layer order.
+	// Optional.
+	Name string `json:"name,omitempty"`
 }
 
 // GenVolumeMounts parses user input into mounts, volumes and overlay volumes

pkg/specgenutil/volumes.go

@@ -747,6 +747,11 @@ func getArtifactVolume(args []string) (*specgen.ArtifactVolume, error) {
 				return nil, fmt.Errorf("%v: %w", name, errOptionArg)
 			}
 			newVolume.Digest = value
+		case "name":
+			if !hasValue {
+				return nil, fmt.Errorf("%v: %w", name, errOptionArg)
+			}
+			newVolume.Name = value
 		default:
 			return nil, fmt.Errorf("%s: %w", name, util.ErrBadMntOption)
 		}

test/e2e/artifact_mount_test.go

@@ -46,6 +46,11 @@ var _ = Describe("Podman artifact mount", func() {
 				mountOpts:     "dst=/data,digest=sha256:e9510923578af3632946ecf5ae479c1b5f08b47464e707b5cbab9819272a9752",
 				containerFile: "/data",
 			},
+			{
+				name:          "single artifact mount with name",
+				mountOpts:     "dst=/tmp,name=abcd",
+				containerFile: "/tmp/abcd",
+			},
 		}
 
 		for _, tt := range tests {
@@ -133,6 +138,20 @@ var _ = Describe("Podman artifact mount", func() {
 					},
 				},
 			},
+			{
+				name:      "multi blob with name",
+				mountOpts: "src=" + ARTIFACT_MULTI + ",dst=/test,name=myname",
+				containerFiles: []expectedFiles{
+					{
+						file:    "/test/myname-0",
+						content: artifactContent1,
+					},
+					{
+						file:    "/test/myname-1",
+						content: artifactContent2,
+					},
+				},
+			},
 		}
 		for _, tt := range tests {
 			By(tt.name)