private List<ApplicationContainer> singleHostContainerCluster(ApplicationContainerCluster cluster, HostResource host, ConfigModelContext context) {
        ApplicationContainer node = new ApplicationContainer(cluster, "container.0", 0, context.getDeployState());
        node.setHostResource(host);
        node.initService(context.getDeployState());
        return List.of(node);
    }
Allocate a container cluster without a nodes tag
config-model/src/main/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilder.java