tests: Build Mariner rootfs initrd

* Adds a new `rootfs-initrd-mariner` build target.
 * Sets the custom initrd path via annotation in `setup.sh` at test
   time.
 * Adapts versions.yaml to specify a `cbl-mariner` initrd variant.
 * Introduces env variable `HOST_OS` at deploy time to enable using a
   custom initrd.
 * Refactors the image builder so that its caller specifies the desired
   guest OS.

Signed-off-by: Aurélien Bombo <abombo@microsoft.com>

tests/integration/kubernetes/setup.sh

@@ -8,13 +8,23 @@ set -o nounset
 set -o pipefail
 
 kubernetes_dir=$(dirname "$(readlink -f "$0")")
+repo_root_dir="$(cd "${kubernetes_dir}/../../../" && pwd)"
 
 set_runtime_class() {
     sed -i -e "s|runtimeClassName: kata|runtimeClassName: kata-${KATA_HYPERVISOR}|" ${kubernetes_dir}/runtimeclass_workloads/*.yaml
 }
 
+set_initrd_path() {
+    if [[ "${KATA_HOST_OS}" = "cbl-mariner" ]]; then
+        initrd_path="/opt/kata/share/kata-containers/kata-containers-initrd-cbl-mariner.img"
+        find ${kubernetes_dir}/runtimeclass_workloads/*.yaml -exec yq write -i {} 'metadata.annotations[io.katacontainers.config.hypervisor.initrd]' "${initrd_path}" \;
+    fi
+}
+
 main() {
+    INSTALL_IN_GOPATH=false bash "${repo_root_dir}/ci/install_yq.sh"
     set_runtime_class
+    set_initrd_path
 }
 
 main "$@"