private ContainerCluster<?> getContainerWithDocproc(Collection<ContainerModel> containers) {
            for (ContainerModel container : containers)
                if (container.getCluster().getDocproc() != null)
                    return container.getCluster();
            return null;
        }
Create a new container cluster for indexing and add it to the Vespa model
config-model/src/main/java/com/yahoo/vespa/model/content/Content.java