public int requireNetworkPort(int port, NetworkPortRequestor service, String suffix) {
        reservePort(service, port);
        String servType = service.getServiceType();
        String configId = service.getConfigId();
        portFinder.use(new NetworkPorts.Allocation(port, servType, configId, suffix));
        return port;
    }
Allocate a specific port number for a service
config-model/src/main/java/com/yahoo/vespa/model/HostPorts.java