openstack-ansible-haproxy_server/doc/source/configure-haproxy.rst

Configuring HAProxy (optional)

HAProxy provides load balancing services and SSL termination when hardware load balancers are not available for high availability architectures deployed by OpenStack-Ansible. The default HAProxy configuration provides highly-available load balancing services via keepalived if there is more than one host in the haproxy_hosts group.

Important

Ensure you review the services exposed by HAProxy and limit access to these services to trusted users and networks only. For more details, refer to the :dev_docs:Securing network access to OpenStack services <reference/architecture/security.html#securing-network-access-to-openstack-services> section.

Note

For a successful installation, you require a load balancer. You may prefer to make use of hardware load balancers instead of HAProxy. If hardware load balancers are in use, then implement the load balancing configuration for services prior to executing the deployment.

To deploy HAProxy within your OpenStack-Ansible environment, define target hosts to 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

If multiple hosts are found in the inventory, deploy HAProxy in a highly-available manner by installing keepalived.

Edit the /etc/openstack_deploy/user_variables.yml to skip the deployment of keepalived along HAProxy when installing HAProxy on multiple hosts. To do this, set the following:

haproxy_use_keepalived: False

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

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 bind the internal and external vip. By default, use br-mgmt.
• On the interface listed above, haproxy_keepalived_internal_vip_cidr and haproxy_keepalived_external_vip_cidr represent the internal and external (respectively) vips (with their prefix length).
• Set additional variables to adapt keepalived in your deployment. 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:

keepalived_use_latest_stable: True

The HAProxy nodes have group vars applied that define the configuration of keepalived. This configuration is stored in group_vars/haproxy_all/keepalived.yml. It contains the variables needed for the keepalived role (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, set the keepalived_ping_address variable in the user_variables.yml file.

Note

The keepalived test works with IPv4 addresses only.

You can adapt keepalived to your environment by either using our override mechanisms (per host with userspace host_vars, per group with userspacegroup_vars, or globally using the userspace user_variables.yml file)

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 fails over to another node and HAProxy serves 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 configures 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, you can provide your 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 you can provide your own certificates and keys to use with HAProxy. User provided certificates should be folded and formatted at 64 characters long. Single line certificates will not be accepted by HAProxy and will result in SSL validation failures. Please have a look here for information on converting your certificate to various formats. If you want to use LetsEncrypt SSL Service you can activate the feature by providing the following configuration in /etc/openstack_deploy/user_variables.yml. Note that this requires that external_lb_vip_address in /etc/openstack_deploy/openstack_user_config.yml is set to the external DNS address.

haproxy_ssl_letsencrypt_enable: true
haproxy_ssl_letsencrypt_email: example@example.com

Warning

There is no certificate distribution implementation at this time, so this will only work for a single haproxy-server environment. The renewal is automatically handled via CRON and currently will shut down haproxy briefly during the certificate renewal. The haproxy shutdown/restart will result in a brief service interruption.

Configuring additional services

Additional haproxy service entries can be configured by setting haproxy_extra_services in /etc/openstack_deploy/user_variables.yml

For more information on the service dict syntax, please reference playbooks/vars/configs/haproxy_config.yml

An example HTTP service could look like:

haproxy_extra_services:
  - service:
      haproxy_service_name: extra-web-service
      haproxy_backend_nodes: "{{ groups['service_group'] | default([]) }}"
      haproxy_ssl: "{{ haproxy_ssl }}"
      haproxy_port: 10000
      haproxy_balance_type: http
      # If backend connections should be secured with SSL (default False)
      haproxy_backend_ssl: True
      haproxy_backend_ca: /path/to/ca/cert.pem
      # Or if certificate validation should be disabled
      # haproxy_backend_ca: False

Additionally, you can specify haproxy services that are not managed in the Ansible inventory by manually specifying their hostnames/IP Addresses:

haproxy_extra_services:
  - service:
      haproxy_service_name: extra-non-inventory-service
      haproxy_backend_nodes:
        - name: nonInvHost01
          ip_addr: 172.0.1.1
        - name: nonInvHost02
          ip_addr: 172.0.1.2
        - name: nonInvHost03
          ip_addr: 172.0.1.3
      haproxy_ssl: "{{ haproxy_ssl }}"
      haproxy_port: 10001
      haproxy_balance_type: http

Adding additional global VIP addresses

In some cases, you might need to add additional internal VIP addresses to the load balancer front end. You can use the HAProxy role to add additional VIPs to all front ends by setting them in the extra_lb_vip_addresses or extra_lb_tls_vip_addresses variables.

The following example shows extra VIP addresses defined in the user_variables.yml file:

extra_lb_vip_addresses:
  - 10.0.0.10
  - 192.168.0.10

The following example shows extra VIP addresses with TLS enabled defined in the user_variables.yml file:

extra_lb_tls_vip_addresses:
  - 10.0.0.10
  - 192.168.0.10

Overriding the address haproxy will bind to

In some cases you may want to override the default of having haproxy bind to the addresses specified in external_lb_vip_address and internal_lb_vip_address. For example if those are hostnames and you want haproxy to bind to IP addresses while preserving the names for TLS-certificates and endpoint URIs.

This can be set in the user_variables.yml file:

haproxy_bind_external_lb_vip_address: 10.0.0.10
haproxy_bind_internal_lb_vip_address: 192.168.0.10

Adding Access Control Lists to HAProxy front end

Adding ACL rules in HAProxy is easy. You just need to define haproxy_acls and add the rules in the variable

Here is an example that shows how to achieve the goal

- service:
       haproxy_service_name: influxdb-relay
       haproxy_acls:
           write_queries:
              rule: "path_sub -i write"
           read_queries:
              rule: "path_sub -i query"
              backend_name: "influxdb"

This will add two acl rules path_sub -i write and path_sub -i query to the front end and use the backend specified in the rule. If no backend is specified it will use a default haproxy_service_name backend.