container-registry: use FEATURE_PACKAGES for IMAGE_FEATURES validation

Move FEATURE_PACKAGES_container-registry from container-image-host.bb
to meta-virt-container.inc so it is available to all image recipes.

image.bbclass check_image_features() auto-discovers FEATURE_PACKAGES_*
variables as valid image features (line 72), so defining the variable
globally is sufficient — no IMAGE_FEATURES[validitems] needed.

This avoids the signature pollution that IMAGE_FEATURES[validitems]
causes when set globally, while allowing container-registry to be
used as an IMAGE_FEATURES value in any image recipe.

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

2 files changed, 11 insertions, 2 deletions

diff --git a/conf/distro/include/meta-virt-container.inc b/conf/distro/include/meta-virt-container.inc
index d3e91eef..6472d855 100644
--- a/conf/distro/include/meta-virt-container.inc
+++ b/conf/distro/include/meta-virt-container.inc
@@ -40,3 +40,13 @@
 
 CONTAINER_RO_REMOVE ?= " ${@bb.utils.contains('VIRTUAL-RUNTIME_container_engine', 'podman', 'shadow', '', d)}"
 ROOTFS_RO_UNNEEDED:remove = "${CONTAINER_RO_REMOVE}"
+
+# Container registry IMAGE_FEATURES support.
+# Defining FEATURE_PACKAGES_container-registry globally makes
+# "container-registry" a valid IMAGE_FEATURES value for any image
+# recipe (image.bbclass check_image_features auto-discovers
+# FEATURE_PACKAGES_* variables). This avoids IMAGE_FEATURES[validitems]
+# which pollutes signatures when set globally.
+# Default is empty (validation only); container-image-host.bb sets the
+# actual packages.
+FEATURE_PACKAGES_container-registry ?= ""
diff --git a/recipes-extended/images/container-image-host.bb b/recipes-extended/images/container-image-host.bb
index 723f0cf5..596b62e0 100644
--- a/recipes-extended/images/container-image-host.bb
+++ b/recipes-extended/images/container-image-host.bb
@@ -84,10 +84,9 @@ REQUIRED_DISTRO_FEATURES:append = " ${@bb.utils.contains('VIRTUAL-RUNTIME_contai
 # of the host name to make it unique
 IMAGE_FEATURES[validitems] += "virt-unique-hostname"
 IMAGE_FEATURES[validitems] += "container-tools"
-IMAGE_FEATURES[validitems] += "container-registry"
-
 # Container registry configuration packages (opt-in via IMAGE_FEATURES += "container-registry")
 # Requires CONTAINER_REGISTRY_URL and/or DOCKER_REGISTRY_INSECURE to be set
+# (overrides empty default from meta-virt-container.inc)
 FEATURE_PACKAGES_container-registry = "\
     ${@bb.utils.contains_any('VIRTUAL-RUNTIME_container_engine', 'docker docker-moby', 'docker-registry-config', '', d)} \
     ${@bb.utils.contains_any('VIRTUAL-RUNTIME_container_engine', 'podman containerd cri-o', 'container-oci-registry-config', '', d)} \