============================== 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 ` 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: .. code-block:: yaml 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. To make keepalived work, edit at least the following variables in ``user_variables.yml``: .. code-block:: yaml 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``: .. code-block:: yaml 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 and private IP address to check its status. The default address is ``193.0.14.129``. To change this default, set the ``keepalived_external_ping_address`` and ``keepalived_internal_ping_address`` variables 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 userspace``group_vars``, or globally using the userspace ``user_variables.yml`` file) If you wish to deploy multiple haproxy hosts without keepalived and provide your own means for failover between them, edit ``/etc/openstack_deploy/user_variables.yml`` to skip the deployment of keepalived. To do this, set the following: .. code-block:: yaml haproxy_use_keepalived: False 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``: .. code-block:: yaml keepalived_external_ping_address: # Public IP address to ping keepalived_internal_ping_address: # Private 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. If external connectivity fails, it is important that internal services can still access an HAProxy instance. In a situation, when ping to some external host fails and internal ping is not separated, all keepalived instances enter the fault state despite internal connectivity being still available. Separate ping check for internal and external connectivity ensures that when one instance fails the other VIP remains in operation. 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: .. code-block:: yaml 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 `_. Using Certificates from LetsEncrypt ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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. The following variables must be set for the haproxy hosts. .. code-block:: yaml haproxy_ssl_letsencrypt_enable: True haproxy_ssl_letsencrypt_install_method: "distro" haproxy_ssl_letsencrypt_email: example@example.com haproxy_interval: 2000 The following variables serve as an example for how to configure a single HAProxy providing SSL termination for a service on the same host, served from 127.0.0.1:80. An additional HAProxy backend is configured which will receive the acme-challenge requests when certificates are renewed. .. code-block:: yaml haproxy_service_configs: # the external facing service which serves the apache test site, with a acl for LE requests - service: haproxy_service_name: test haproxy_redirect_http_port: 80 #redirect port 80 to port ssl haproxy_redirect_scheme: "https if !{ ssl_fc } !{ path_beg /.well-known/acme-challenge/ }" #redirect all non-ssl traffic to ssl except acme-challenge haproxy_port: 443 haproxy_frontend_acls: #use a frontend ACL specify the backend to use for acme-challenge letsencrypt-acl: rule: "path_beg /.well-known/acme-challenge/" backend_name: letsencrypt haproxy_ssl: True haproxy_backend_nodes: #apache is running on locally on 127.0.0.1:80 serving a dummy site - name: local-test-service ip_addr: 127.0.0.1 haproxy_balance_type: http haproxy_backend_port: 80 haproxy_backend_options: - "httpchk HEAD /" # request to use for health check for the example service # an internal only service for acme-challenge whose backend is certbot on the haproxy host - service: haproxy_service_name: letsencrypt haproxy_backend_nodes: - name: localhost ip_addr: {{ ansible_host }} #certbot binds to the internal IP backend_rise: 1 #quick rise and fall time for multinode deployment to succeed backend_fall: 2 haproxy_bind: - 127.0.0.1 #bind to 127.0.0.1 as the local internal address will be used by certbot haproxy_port: 8888 #certbot is configured with http-01-port to be 8888 haproxy_balance_type: http It is possible to use an HA configuration of HAProxy with certificates initialised and renewed using certbot by setting haproxy_backend_nodes for the LetsEncrypt service to include all HAProxy internal addresses. Each HAProxy instance will be checking for certbot running on its own node plus each of the others, and direct any incoming acme-challenge requests to the HAProxy instance which is performing a renewal. It is necessary to configure certbot to bind to the HAproxy node local internal IP address via the haproxy_ssl_letsencrypt_certbot_bind_address variable in a H/A setup. Using Certificates from LetsEncrypt (legacy method) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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. .. code-block:: yaml 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. .. _Securing services with SSL certificates: https://docs.openstack.org/project-deploy-guide/openstack-ansible/draft/app-advanced-config-sslcertificates.html 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: .. code-block:: yaml 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 to use system CA for validation # haproxy_backend_ca: True # 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: .. code-block:: yaml 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: .. code-block:: yaml 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: .. code-block:: yaml 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: .. code-block:: yaml 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 .. code-block:: yaml - 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. If a frontend service directs to multiple backend services using ACLs, and a backend service does not require its own corresponding front-end, the `haproxy_backend_only` option can be specified: .. code-block:: yaml - service: haproxy_service_name: influxdb haproxy_backend_only: true # Directed by the 'influxdb-relay' service above haproxy_backend_nodes: - name: influxdb-service ip_addr: 10.100.10.10 Adding prometheus metrics to haproxy ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Since haproxy 2.0 it's possible to exposes prometheus metrics. https://www.haproxy.com/blog/haproxy-exposes-a-prometheus-metrics-endpoint/ if you need to create a frontend for it you can use the `haproxy_frontend_only` option: .. code-block:: yaml - service: haproxy_service_name: prometheus-metrics haproxy_port: 8404 haproxy_bind: - '127.0.0.1' haproxy_whitelist_networks: "{{ haproxy_whitelist_networks }}" haproxy_frontend_only: True haproxy_frontend_raw: - 'http-request use-service prometheus-exporter if { path /metrics }' haproxy_service_enabled: True haproxy_balance_type: 'http'