image-oci: fix symlink loop on image rebuild

Use ln -sfn instead of ln -sf to prevent creating symlinks inside
existing symlink target directories. Without -n, if the convenience
symlink (e.g., container-base-latest-oci) already exists and points
to a directory, ln -sf creates the new symlink inside that directory
rather than replacing it, resulting in a self-referencing symlink.

This manifests as "Too many levels of symbolic links" errors when
container-bundle tries to copy OCI images after a rebuild.

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

2 files changed, 9 insertions, 6 deletions

diff --git a/classes/image-oci-sloci-image.inc b/classes/image-oci-sloci-image.inc
index 9248489f..db86ab15 100644
--- a/classes/image-oci-sloci-image.inc
+++ b/classes/image-oci-sloci-image.inc
@@ -72,18 +72,19 @@ IMAGE_CMD:oci() {
     fi
 
     # create a convenience symlink
-    ln -sf ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci ${IMAGE_BASENAME}-${OCI_IMAGE_TAG}-oci
+    # Use -n to avoid creating link inside existing symlink target directory
+    ln -sfn ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}-oci ${IMAGE_BASENAME}-${OCI_IMAGE_TAG}-oci
 
     if [ -n "${OCI_IMAGE_TAR_OUTPUT}" ]; then
         # 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
+        ln -sfn ${IMAGE_NAME}${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
+        ln -sfn "${IMAGE_NAME}${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 9bd154fb..1d4863b3 100644
--- a/classes/image-oci-umoci.inc
+++ b/classes/image-oci-umoci.inc
@@ -123,13 +123,15 @@ IMAGE_CMD:oci() {
         tar -cf "$image_name-dir.tar" "$image_name"
 
         # create a convenience symlink
-        ln -sf "$image_name.tar" "${IMAGE_BASENAME}-$image_tag-oci.tar"
-        ln -sf "$image_name-dir.tar" "${IMAGE_BASENAME}-$image_tag-oci-dir.tar"
+        # Use -n to avoid creating link inside existing symlink target directory
+        ln -sfn "$image_name.tar" "${IMAGE_BASENAME}-$image_tag-oci.tar"
+        ln -sfn "$image_name-dir.tar" "${IMAGE_BASENAME}-$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 ${IMAGE_BASENAME}-$image_tag-oci
+    # Use -n to avoid creating link inside existing symlink target directory
+    ln -sfn $image_name ${IMAGE_BASENAME}-$image_tag-oci
 }