private void addMetricsProxyCluster(List<HostResource> hosts, DeployState deployState) {
        metricsProxyCluster = new MetricsProxyContainerCluster(this, "metrics", deployState);
        int index = 0;
        for (var host : hosts) {
            // Send hostname to be used in configId (instead of index), as the sorting of hosts seems to be unstable
            // between config changes, even when the set of hosts is unchanged.
            var container = new MetricsProxyContainer(metricsProxyCluster, host, index, deployState);
            addAndInitializeService(deployState, host, container);
            metricsProxyCluster.addContainer(container);
        }
    }
Adds services to all hosts in the system.
config-model/src/main/java/com/yahoo/vespa/model/admin/Admin.java