Expose RootFS in image inspect

Fixes #20451

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Upstream-commit: 14dc4a7158a141b5c13aa63231e467f0c3235850
Component: engine

components/engine/daemon/daemon.go

@@ -1164,6 +1164,7 @@ func (daemon *Daemon) LookupImage(name string) (*types.ImageInspect, error) {
 		Os:              img.OS,
 		Size:            size,
 		VirtualSize:     size, // TODO: field unused, deprecate
+		RootFS:          rootFSToAPIType(img.RootFS),
 	}
 
 	imageInspect.GraphDriver.Name = daemon.GraphDriverName()

components/engine/daemon/daemon_unix.go

@@ -1092,3 +1092,14 @@ func (daemon *Daemon) stats(c *container.Container) (*types.StatsJSON, error) {
 func (daemon *Daemon) setDefaultIsolation() error {
 	return nil
 }
+
+func rootFSToAPIType(rootfs *image.RootFS) types.RootFS {
+	var layers []string
+	for _, l := range rootfs.DiffIDs {
+		layers = append(layers, l.String())
+	}
+	return types.RootFS{
+		Type:   rootfs.Type,
+		Layers: layers,
+	}
+}

components/engine/daemon/daemon_windows.go

@@ -453,3 +453,15 @@ func (daemon *Daemon) setDefaultIsolation() error {
 	logrus.Infof("Windows default isolation mode: %s", daemon.defaultIsolation)
 	return nil
 }
+
+func rootFSToAPIType(rootfs *image.RootFS) types.RootFS {
+	var layers []string
+	for _, l := range rootfs.DiffIDs {
+		layers = append(layers, l.String())
+	}
+	return types.RootFS{
+		Type:      rootfs.Type,
+		Layers:    layers,
+		BaseLayer: rootfs.BaseLayer,
+	}
+}