Map<String, List<String>> firewallRules = clusterSpec.getFirewallRules();
for (String role: firewallRules.keySet()) {
Rule rule = Rule.create();
if (role == null) {
rule.destination(event.getCluster().getInstances());
} else {
rule.destination(RolePredicates.role(role));
}
List<String> ports = firewallRules.get(role);