conf: introduce container configuration values

From the configuration file itself:

 These variables represent groupings of functionality in the CNCF
 landscape. In particular, they are areas where there is a choice
 between more than one implementation or an area where abstraction
 is beneficial.

 The contents of the variables are are runtime components that
 recipes may use for RDEPENDS.

 Build dependencies are not typically flexible, so do not currently
 have DEPENDS equivalents for the components (i.e. DEPENDS on runc
 versus crun).

 Distro features such as kubernetes or other container stacks
 can be used to set different defaults for these variables.

 Note: these are "global" values, since they represent choices.
 If more than of a grouping is required on target, then the variable
 can be appended or set to multiple values. That being said, Recipes
 should generally agree on the values, hence the global namespace.
 Recipe specific choices  can still be done, but they risk
 conflicting on target or causing runtime issues / errors.

 ## CNCF "components"

 # engines: docker-ce/docker-moby, virtual-containerd, cri-o, podman
 VIRTUAL-RUNTIME_container_engine ??= "podman"
 # runtime: runc, crun, runv, runx
 VIRTUAL-RUNTIME_container_runtime ??= "virtual-runc"
 # networking: cni, netavark
 VIRTUAL-RUNTIME_container_networking ??= "cni"
 # dns: cni, aardvark-dns
 VIRTUAL-RUNTIME_container_dns ??= "cni"
 # orchestration: k8s, k3s
 VIRTUAL-RUNTIME_container_orchestration ??= "k3s"

 ## Kubernetes terminology "components"

 VIRTUAL-RUNTIME_cri ??= "containerd"
 VIRTUAL-RUNTIME_cni ??= "cni"

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

1 files changed, 6 insertions, 0 deletions

diff --git a/classes/meta-virt-container-cfg.bbclass b/classes/meta-virt-container-cfg.bbclass
new file mode 100644
index 00000000..0688f525
--- /dev/null
+++ b/classes/meta-virt-container-cfg.bbclass
@@ -0,0 +1,6 @@
+# We need to set the Xen meta-virt config components, only if "xen"
+# 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_CONTAINER_CONFIG_PATH file.
+
+include ${@bb.utils.contains('DISTRO_FEATURES', 'virtualization', '${META_VIRT_CONTAINER_CONFIG_PATH}', '', d)}