openstack-ansible/doc/source/install-guide/configure-haproxy.rst

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Configuring HAProxy (optional)

HAProxy provides load balancing for high availability architectures deployed by OpenStack-Ansible. The default HAProxy configuration provides highly-available load balancing services via keepalived if there are more than one hosts in the haproxy_hosts group.

Note

Deployers must review the services exposed by HAProxy and must limit access to these services to trusted users and networks only. For more details, refer to the least-access-openstack-services section.

Note

A load balancer is required for a successful installation. Deployers may prefer to make use of hardware load balancers instead of haproxy. If hardware load balancers are used then the load balancing configuration for services must be implemented prior to executing the deployment.

To deploy HAProxy within your OpenStack-Ansible environment, define target hosts which should run HAProxy:

haproxy_hosts:
  infra1:
    ip: 172.29.236.101
  infra2:
    ip: 172.29.236.102
  infra3:
    ip: 172.29.236.103

There is an example configuration file already provided in /etc/openstack_deploy/conf.d/haproxy.yml.example. Rename the file to haproxy.yml and configure it with the correct target hosts to use HAProxy in an OpenStack-Ansible deployment.

Making HAProxy highly-available

HAProxy will be deployed in a highly-available manner, by installing keepalived if multiple hosts are found in the inventory.

To skip the deployment of keepalived along HAProxy when installing HAProxy on multiple hosts, edit the /etc/openstack_deploy/user_variables.yml by setting:

haproxy_use_keepalived: False

Otherwise, edit at least the following variables in user_variables.yml to make keepalived work:

haproxy_keepalived_external_vip_cidr: 192.168.0.4/25
haproxy_keepalived_internal_vip_cidr: 172.29.236.54/16
haproxy_keepalived_external_interface: br-flat
haproxy_keepalived_internal_interface: br-mgmt

• haproxy_keepalived_internal_interface and haproxy_keepalived_external_interface represent the interfaces on the deployed node where the keepalived nodes will bind the internal/external vip. By default the br-mgmt will be used.
• haproxy_keepalived_internal_vip_cidr and haproxy_keepalived_external_vip_cidr represents the internal and external (respectively) vips (with their prefix length) that will be used on keepalived host with the master status, on the interface listed above.
• Additional variables can be set to adapt keepalived in the deployed environment. Please refer to the user_variables.yml for more descriptions.

To always deploy (or upgrade to) the latest stable version of keepalived, edit the /etc/openstack_deploy/user_variables.yml by setting:

keepalived_use_latest_stable: True

The HAProxy playbook reads the vars/configs/keepalived_haproxy.yml variable file and provides its content to the keepalived role for keepalived master and backup nodes.

Keepalived pings a public IP address to check its status. The default address is 193.0.14.129. To change this default, for example to your gateway, set the keepalived_ping_address variable in the user_variables.yml file.

Note

The keepalived test works with IPv4 addresses only.

You can define additional variables to adapt keepalived to the deployed environment. Refer to the user_variables.yml file for more information. Optionally, you can use your own variable file, as follows:

haproxy_keepalived_vars_file: /path/to/myvariablefile.yml

Configuring keepalived ping checks

OpenStack-Ansible configures keepalived with a check script that pings an external resource and uses that ping to determine if a node has lost network connectivity. If the pings fail, keepalived will fail over to another node and HAProxy will serve requests there.

The destination address, ping count and ping interval are configurable via Ansible variables in /etc/openstack_deploy/user_variables.yml:

keepalived_ping_address:         # IP address to ping
keepalived_ping_count:           # ICMP packets to send (per interval)
keepalived_ping_interval:        # How often ICMP packets are sent

By default, OpenStack-Ansible will configure keepalived to ping one of the root DNS servers operated by RIPE. You can change this IP address to a different external address or another address on your internal network.

Securing HAProxy communication with SSL certificates

The OpenStack-Ansible project provides the ability to secure HAProxy communications with self-signed or user-provided SSL certificates. By default, self-signed certificates are used with HAProxy. However, deployers can provide their own certificates by using the following Ansible variables:

haproxy_user_ssl_cert:          # Path to certificate
haproxy_user_ssl_key:           # Path to private key
haproxy_user_ssl_ca_cert:       # Path to CA certificate

Refer to Securing services with SSL certificates for more information on these configuration options and how deployers can provide their own certificates and keys to use with HAProxy.

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