oci-image: create two different tar outputs

The original tar output of the oci image followed the sloci-image
convention of putting the oci contents into a subdirectory in the
tarball. This allows it to work directly with skopeo, etc, but it
isn't the format that tools like podman expect in an oci-image
tarball.

We move the original format to have "-dir" in the name, and let
the more simply named one be the oci-image format as expcted by
various 3rd party tools

   1) image_name.tar: compatible with oci tar format, blobs and
      rootfs are at the top level. Can load directly from something like podman

   2) image_name-dir.tar: original format from meta-virt, is just a
      tar'd up oci image directory (compatible with skopeo :dir format)

We also fix a bug in the sloci-image backend, where the sloci tar
was removing the raw oci image directory leaving a dangling symlink.

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

2 files changed, 28 insertions, 2 deletions

diff --git a/classes/image-oci-sloci-image.inc b/classes/image-oci-sloci-image.inc
index 379f6fe0..9248489f 100644
--- a/classes/image-oci-sloci-image.inc
+++ b/classes/image-oci-sloci-image.inc
@@ -65,10 +65,25 @@ IMAGE_CMD:oci() {
                 ${oci_image_port_options} \
                 ${IMAGE_ROOTFS} ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci:${OCI_IMAGE_TAG}
 
+    if [ -n "${OCI_IMAGE_TAR_OUTPUT}" ]; then
+        # if tar is specified, sloci-image is removing the directory that we need for a secondary
+        # tar format, so we need to restore it.
+        tar xf ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci-${OCI_IMAGE_TAG}-${OCI_IMAGE_ARCH}-linux.oci-image.tar
+    fi
+
     # create a convenience symlink
     ln -sf ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci ${IMAGE_BASENAME}-${OCI_IMAGE_TAG}-oci
 
     if [ -n "${OCI_IMAGE_TAR_OUTPUT}" ]; then
-        ln -sf ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci-${OCI_IMAGE_TAG}-${OCI_IMAGE_ARCH}-linux.oci-image.tar ${IMAGE_BASENAME}-${OCI_IMAGE_TAG}-oci.tar
+        # move the sloci output to a naming convention that matches what we do with umoci, thie
+        # default creates a subdirectory, so it get the "-dir" in the name
+        mv ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci-${OCI_IMAGE_TAG}-${OCI_IMAGE_ARCH}-linux.oci-image.tar ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci-${OCI_IMAGE_TAG}-${OCI_IMAGE_ARCH}-linux.oci-dir.tar
+        ln -sf ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci-${OCI_IMAGE_TAG}-${OCI_IMAGE_ARCH}-linux.oci-dir.tar ${IMAGE_BASENAME}-${OCI_IMAGE_TAG}-oci-dir.tar
+
+        (
+            cd "${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci"
+            tar -cf ../"${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci-${OCI_IMAGE_TAG}-${OCI_IMAGE_ARCH}-linux.oci-image.tar" "."
+        )
+        ln -sf "${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci-${OCI_IMAGE_TAG}-${OCI_IMAGE_ARCH}-linux.oci-image.tar" ${IMAGE_BASENAME}-${OCI_IMAGE_TAG}-oci.tar
     fi
 }
diff --git a/classes/image-oci-umoci.inc b/classes/image-oci-umoci.inc
index 38917d4f..58e46681 100644
--- a/classes/image-oci-umoci.inc
+++ b/classes/image-oci-umoci.inc
@@ -106,14 +106,25 @@ IMAGE_CMD:oci() {
     umoci config --image $image_name:${OCI_IMAGE_TAG} --author ${OCI_IMAGE_AUTHOR_EMAIL}
 
     # make a tar version of the image direcotry
+    #  1) image_name.tar: compatible with oci tar format, blobs and rootfs
+    #     are at the top level. Can load directly from something like podman
+    #  2) image_name-dir.tar: original format from meta-virt, is just a tar'd
+    #     up oci image directory (compatible with skopeo :dir format)
     if [ -n "${OCI_IMAGE_TAR_OUTPUT}" ]; then
-        tar -cf "$image_name.tar" "$image_name"
+        (
+            cd "$image_name"
+            tar -cf ../"$image_name.tar" "."
+        )
+        tar -cf "$image_name-dir.tar" "$image_name"
+
         # create a convenience symlink
         ln -sf "$image_name.tar" "${IMAGE_BASENAME}-${OCI_IMAGE_TAG}-oci.tar"
+        ln -sf "$image_name-dir.tar" "${IMAGE_BASENAME}-${OCI_IMAGE_TAG}-oci-dir.tar"
     fi
 
     # We could make this optional, since the bundle is directly runnable via runc
     rm -rf $image_bundle_name
 
+    # This is the OCI image directory, which is technically the "image" as specified
     ln -sf $image_name ${IMAGE_BASENAME}-${OCI_IMAGE_TAG}-oci
 }