AdditionalSupport for SubPath volume mounts

Add support for inspecting Mounts which include SubPaths.

Handle SubPaths for kubernetes image volumes.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

libpod/container_inspect.go

@@ -258,6 +258,7 @@ func (c *Container) GetMounts(namedVolumes []*ContainerNamedVolume, imageVolumes
 		mountStruct.Type = "volume"
 		mountStruct.Destination = volume.Dest
 		mountStruct.Name = volume.Name
+		mountStruct.SubPath = volume.SubPath
 
 		// For src and driver, we need to look up the named
 		// volume.
@@ -284,6 +285,7 @@ func (c *Container) GetMounts(namedVolumes []*ContainerNamedVolume, imageVolumes
 		mountStruct.Destination = volume.Dest
 		mountStruct.Source = volume.Source
 		mountStruct.RW = volume.ReadWrite
+		mountStruct.SubPath = volume.SubPath
 
 		inspectMounts = append(inspectMounts, mountStruct)
 	}

libpod/define/container_inspect.go

@@ -285,6 +285,9 @@ type InspectMount struct {
 	// Mount propagation for the mount. Can be empty if not specified, but
 	// is always printed - no omitempty.
 	Propagation string `json:"Propagation"`
+	// SubPath object from the volume. Specified as a path within
+	// the source volume to be mounted at the Destination.
+	SubPath string `json:"SubPath,omitempty"`
 }
 
 // InspectContainerState provides a detailed record of a container's current

pkg/specgen/generate/kube/kube.go

@@ -575,7 +575,7 @@ func ToSpecGen(ctx context.Context, opts *CtrSpecGenOptions) (*specgen.SpecGener
 				Destination: volume.MountPath,
 				ReadWrite:   false,
 				Source:      volumeSource.Source,
-				SubPath:     "",
+				SubPath:     volume.SubPath,
 			}
 			s.ImageVolumes = append(s.ImageVolumes, &imageVolume)
 		default:

test/system/060-mount.bats

@@ -148,6 +148,14 @@ load helpers
     run_podman run --rm --mount "${mountopts},readwrite=true" $iname \
                touch /image-mount/readwrite
 
+    tmpctr="c-$(safename)"
+    subpathopts="type=image,src=$iname,dst=/image-mount,subpath=/etc"
+    run_podman run --name $tmpctr --mount "${subpathopts}" $iname \
+               ls /image-mount/shadow
+    run_podman inspect $tmpctr --format '{{ (index .Mounts 0).SubPath }}'
+    assert "$output" == "/etc" "SubPath contains /etc"
+    run_podman rm $tmpctr
+
     # The rest of the tests below are meaningless under remote
     if is_remote; then
         run_podman rmi $iname