conf: add k8s distro feature

Add support for a new distro feature to control kubernetes versions
and related configuration.

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

README

@@ -28,6 +28,7 @@ that may also be enabled:
 
  - xen: enables xen functionality in various packages (kernel, libvirt, etc)
  - kvm: enables KVM configurations in the kernel and autoloads modules
+ - k8s: enables kubernets configurations in the kernel, tools and configuration
  - aufs: enables aufs support in docker and linux-yocto
  - x11: enable xen and libvirt functionality related to x11
  - selinux: enables functionality in libvirt and lxc

classes/meta-virt-k8s-cfg.bbclass

@@ -0,0 +1,6 @@
+# We need to load the meta-virt config components, only if "k8s"
+# is in the distro features.  Since we don't know the distro flags during
+# layer.conf load time, we delay using a special bbclass that simply includes
+# the K8S_CONFIG_PATH file.
+
+include ${K8S_CONFIG_PATH}

conf/layer.conf

@@ -43,6 +43,8 @@ INHERIT += "sanity-meta-virt"
 # We need to load the meta-virt config components, only if "virtualization"
 # is in the distro features.  Since we don't know the distro flags during
 # layer.conf load time, we delay using a special bbclass that simply includes
-# the META_VIRT_CONFIG_PATH file.
+# the META_VIRT_CONFIG_PATH file, and likewise for the k8s configs
 META_VIRT_CONFIG_PATH = "${LAYERDIR}/conf/distro/include/meta-virt-default-versions.inc"
+K8S_CONFIG_PATH = "${LAYERDIR}/conf/distro/include/k8s-versions.inc"
 USER_CLASSES_append = " ${@bb.utils.contains('DISTRO_FEATURES', 'virtualization', 'meta-virt-cfg', '', d)}"
+USER_CLASSES_append = " ${@bb.utils.contains('DISTRO_FEATURES', 'k8s', 'meta-virt-k8s-cfg', '', d)}"