Chapter 2. Security enhancements The following sections provide some suggestions to harden the security of your overcloud. 2.1. Using secure root user access The overcloud image automatically contains hardened security for the root user. For example, each deployed overcloud node automatically disables direct SSH access to the root user. You can still access the root user on overcloud nodes. Each overcloud node has a tripleo-admin user account. This user account contains the undercloud public SSH key, which provides SSH access without a password from the undercloud to the overcloud node. Prerequisites You have an installed Red Hat OpenStack Platform director environment. You are logged into the director as stack. Procedure On the undercloud node, log in to the an overcloud node through SSH as the tripleo-admin user. Switch to the root user with sudo -i . 2.2. Adding services to the overcloud firewall When you deploy Red Hat OpenStack Platform, each core service is deployed with a default set of firewall rules on each overcloud node. You can use the ExtraFirewallRules parameter to create rules to open ports for additional services, or create rules to restrict services. Each rule name becomes the comment for the respective iptables rule. Each rule name starts with a three-digit prefix to help Puppet order the rules in the final iptables file. The default Red Hat OpenStack Platform rules use prefixes in the 000 to 200 range. When you create rules for new services, prefix the name with a three-digit number higher than 200. Procedure Use a string to define each rule name under the ExtraFireWallRules parameter. You can use the following parameters under the rule name to define the rule: dport:: The destination port associated to the rule. proto:: The protocol associated to the rule. Defaults to tcp . action:: The action policy associated to the rule. Defaults to accept . source:: The source IP address associated to the rule. The following example shows how to use rules to open additional ports for custom applications: Note When you do not set the action parameter, the result is accept . You can only set the action parameter to drop , insert , or append . Include the ~/templates/firewall.yaml file in the openstack overcloud deloy command. Include all templates that are necessary for your deployment: 2.3. Removing services from the overcloud firewall You can use rules to restrict services. The number that you use in the rule name determines where in iptables the rule will be inserted. The following procedure shows how to restrict the rabbitmq service to the InternalAPI network. Procedure On a Controller node, find the number of the default iptables rule for rabbitmq : [tripleo-admin@overcloud-controller-2 ~]USD sudo iptables -L | grep rabbitmq ACCEPT tcp -- anywhere anywhere multiport dports vtr-emulator,epmd,amqp,25672,25673:25683 state NEW /* 109 rabbitmq-bundle ipv4 */ In an environment file uder parameter_defaults , use the ExtraFirewallRules parameter to restrict rabbitmq to the InternalApi network. The rule is given a lower number thant the default rabbitmq rule number or 109: Note When you do not set the action parameter, the result is accept . You can only set the action parameter to drop , insert , or append . Include the ~/templates/firewall.yaml file in the openstack overcloud deloy command. Include all templates that are necessary for your deployment: 2.4. Changing the Simple Network Management Protocol (SNMP) strings Director provides a default read-only SNMP configuration for your overcloud. It is advisable to change the SNMP strings to mitigate the risk of unauthorized users learning about your network devices. Note When you configure the ExtraConfig interface with a string parameter, you must use the following syntax to ensure that heat and Hiera do not interpret the string as a Boolean value: '"<VALUE>"' . Set the following hieradata using the ExtraConfig hook in an environment file for your overcloud: SNMP traditional access control settings snmp::ro_community IPv4 read-only SNMP community string. The default value is public . snmp::ro_community6 IPv6 read-only SNMP community string. The default value is public . snmp::ro_network Network that is allowed to RO query the daemon. This value can be a string or an array. Default value is 127.0.0.1 . snmp::ro_network6 Network that is allowed to RO query the daemon with IPv6. This value can be a string or an array. The default value is ::1/128 . tripleo::profile::base::snmp::snmpd_config Array of lines to add to the snmpd.conf file as a safety valve. The default value is [] . See the SNMP Configuration File web page for all available options. For example: This changes the read-only SNMP community string on all nodes. SNMP view-based access control settings (VACM) snmp::com2sec An array of VACM com2sec mappings. Must provide SECNAME, SOURCE and COMMUNITY. snmp::com2sec6 An array of VACM com2sec6 mappings. Must provide SECNAME, SOURCE and COMMUNITY. For example: This changes the read-only SNMP community string on all nodes. For more information, see the snmpd.conf man page. 2.5. Using the Open vSwitch firewall You can configure security groups to use the Open vSwitch (OVS) firewall driver in Red Hat OpenStack Platform director. Use the NeutronOVSFirewallDriver parameter to specify firewall driver that you want to use: iptables_hybrid - Configures the Networking service (neutron) to use the iptables/hybrid based implementation. openvswitch - Configures the Networking service to use the OVS firewall flow-based driver. The openvswitch firewall driver includes higher performance and reduces the number of interfaces and bridges used to connect guests to the project network. Important Multicast traffic is handled differently by the Open vSwitch (OVS) firewall driver than by the iptables firewall driver. With iptables, by default, VRRP traffic is denied, and you must enable VRRP in the security group rules for any VRRP traffic to reach an endpoint. With OVS, all ports share the same OpenFlow context, and multicast traffic cannot be processed individually per port. Because security groups do not apply to all ports (for example, the ports on a router), OVS uses the NORMAL action and forwards multicast traffic to all ports as specified by RFC 4541. Note The iptables_hybrid option is not compatible with OVS-DPDK. The openvswitch option is not compatible with OVS Hardware Offload. Configure the NeutronOVSFirewallDriver parameter in the network-environment.yaml file: NeutronOVSFirewallDriver: openvswitch NeutronOVSFirewallDriver : Configures the name of the firewall driver that you want to use when you implement security groups. Possible values depend on your system configuration. Some examples are noop , openvswitch , and iptables_hybrid . The default value of an empty string results in a supported configuration.

Commands:
cat > ~/templates/firewall.yaml <<EOF parameter_defaults: ExtraFirewallRules: '300 allow custom application 1': dport: 999 proto: udp '301 allow custom application 2': dport: 8081 proto: tcp EOF
openstack overcloud deploy --templates / -e /home/stack/templates/firewall.yaml / .
[tripleo-admin@overcloud-controller-2 ~]USD sudo iptables -L | grep rabbitmq ACCEPT tcp -- anywhere anywhere multiport dports vtr-emulator,epmd,amqp,25672,25673:25683 state NEW /* 109 rabbitmq-bundle ipv4 */
cat > ~/templates/firewall.yaml <<EOF parameter_defaults: ExtraFirewallRules: '098 allow rabbit from internalapi network': dport: - 4369 - 5672 - 25672 proto: tcp source: 10.0.0.0/24 '099 drop other rabbit access': dport: - 4369 - 5672 - 25672 proto: tcp action: drop EOF
openstack overcloud deploy --templates / -e /home/stack/templates/firewall.yaml / .
parameter_defaults: ExtraConfig: snmp::ro_community: mysecurestring snmp::ro_community6: myv6securestring
parameter_defaults: ExtraConfig: snmp::com2sec: ["notConfigUser default mysecurestring"] snmp::com2sec6: ["notConfigUser default myv6securestring"]
NeutronOVSFirewallDriver: openvswitch