09df6fc1aa
A combination of durable queues and classic queue mirroring can be used to provide high availability of RabbitMQ. However, these options should only be used together, otherwise the system will become unstable. Using the flag ``om_enable_rabbitmq_high_availability`` will either enable both options at once, or neither of them. There are some queues that should not be mirrored: * ``reply`` queues (these have a single consumer and TTL policy) * ``fanout`` queues (these have a TTL policy) * ``amq`` queues (these are auto-delete queues, with a single consumer) An exclusionary pattern is used in the classic mirroring policy. This pattern is ``^(?!(amq\\.)|(.*_fanout_)|(reply_)).*`` Change-Id: I51c8023b260eb40b2eaa91bd276b46890c215c25
121 lines
4.8 KiB
ReStructuredText
121 lines
4.8 KiB
ReStructuredText
.. _rabbitmq:
|
|
|
|
========
|
|
RabbitMQ
|
|
========
|
|
|
|
RabbitMQ is a message broker written in Erlang.
|
|
It is currently the default provider of message queues in Kolla Ansible
|
|
deployments.
|
|
|
|
TLS encryption
|
|
~~~~~~~~~~~~~~
|
|
|
|
There are a number of channels to consider when securing RabbitMQ
|
|
communication. Kolla Ansible currently supports TLS encryption of the
|
|
following:
|
|
|
|
* client-server traffic, typically between OpenStack services using the
|
|
:oslo.messaging-doc:`oslo.messaging </>` library and RabbitMQ
|
|
* RabbitMQ Management API and UI (frontend connection to HAProxy only)
|
|
|
|
Encryption of the following channels is not currently supported:
|
|
|
|
* RabbitMQ cluster traffic between RabbitMQ server nodes
|
|
* RabbitMQ CLI communication with RabbitMQ server nodes
|
|
* RabbitMQ Management API and UI (backend connection from HAProxy to RabbitMQ)
|
|
|
|
Client-server
|
|
-------------
|
|
|
|
Encryption of client-server traffic is enabled by setting
|
|
``rabbitmq_enable_tls`` to ``true``. Additionally, certificates and keys must
|
|
be available in the following paths (in priority order):
|
|
|
|
Certificates:
|
|
|
|
* ``"{{ kolla_certificates_dir }}/{{ inventory_hostname }}/rabbitmq-cert.pem"``
|
|
* ``"{{ kolla_certificates_dir }}/{{ inventory_hostname }}-cert.pem"``
|
|
* ``"{{ kolla_certificates_dir }}/rabbitmq-cert.pem"``
|
|
|
|
Keys:
|
|
|
|
* ``"{{ kolla_certificates_dir }}/{{ inventory_hostname }}/rabbitmq-key.pem"``
|
|
* ``"{{ kolla_certificates_dir }}/{{ inventory_hostname }}-key.pem"``
|
|
* ``"{{ kolla_certificates_dir }}/rabbitmq-key.pem"``
|
|
|
|
The default for ``kolla_certificates_dir`` is ``/etc/kolla/certificates``.
|
|
|
|
The certificates must be valid for the IP address of the host running RabbitMQ
|
|
on the API network.
|
|
|
|
Additional TLS configuration options may be passed to RabbitMQ via
|
|
``rabbitmq_tls_options``. This should be a dict, and the keys will be prefixed
|
|
with ``ssl_options.``. For example:
|
|
|
|
.. code-block:: yaml
|
|
|
|
rabbitmq_tls_options:
|
|
ciphers.1: ECDHE-ECDSA-AES256-GCM-SHA384
|
|
ciphers.2: ECDHE-RSA-AES256-GCM-SHA384
|
|
ciphers.3: ECDHE-ECDSA-AES256-SHA384
|
|
honor_cipher_order: true
|
|
honor_ecc_order: true
|
|
|
|
Details on configuration of RabbitMQ for TLS can be found in the `RabbitMQ
|
|
documentation <https://www.rabbitmq.com/ssl.html>`__.
|
|
|
|
When ``om_rabbitmq_enable_tls`` is ``true`` (it defaults to the value of
|
|
``rabbitmq_enable_tls``), applicable OpenStack services will be configured to
|
|
use oslo.messaging with TLS enabled. The CA certificate is configured via
|
|
``om_rabbitmq_cacert`` (it defaults to ``rabbitmq_cacert``, which points to the
|
|
system's trusted CA certificate bundle for TLS). Note that there is currently
|
|
no support for using client certificates.
|
|
|
|
For testing purposes, Kolla Ansible provides the ``kolla-ansible certificates``
|
|
command, which will generate self-signed certificates for RabbitMQ if
|
|
``rabbitmq_enable_tls`` is ``true``.
|
|
|
|
Management API and UI
|
|
---------------------
|
|
|
|
The management API and UI are accessed via HAProxy, exposed only on the
|
|
internal VIP. As such, traffic to this endpoint is encrypted when
|
|
``kolla_enable_tls_internal`` is ``true``. See :ref:`tls-configuration`.
|
|
|
|
Passing arguments to RabbitMQ server's Erlang VM
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Erlang programs run in an Erlang VM (virtual machine) and use the Erlang
|
|
runtime. The Erlang VM can be configured.
|
|
|
|
Kolla Ansible makes it possible to pass arguments to the Erlang VM via the
|
|
usage of the ``rabbitmq_server_additional_erl_args`` variable. The contents of
|
|
it are appended to the ``RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS`` environment
|
|
variable which is passed to the RabbitMQ server startup script. Kolla Ansible
|
|
already configures RabbitMQ server for IPv6 (if necessary). Any argument can be
|
|
passed there as documented in https://www.rabbitmq.com/runtime.html
|
|
|
|
The default value for ``rabbitmq_server_additional_erl_args`` is ``+S 2:2 +sbwt
|
|
none +sbwtdcpu none +sbwtdio none``.
|
|
|
|
By default RabbitMQ starts N schedulers where N is the number of CPU cores,
|
|
including hyper-threaded cores. This is fine when you assume all CPUs are
|
|
dedicated to RabbitMQ. Its not a good idea in a typical Kolla Ansible setup.
|
|
Here we go for two scheduler threads (``+S 2:2``). More details can be found
|
|
here: https://www.rabbitmq.com/runtime.html#scheduling and here:
|
|
https://erlang.org/doc/man/erl.html#emulator-flags
|
|
|
|
The ``+sbwt none +sbwtdcpu none +sbwtdio none`` arguments prevent busy waiting
|
|
of the scheduler, for more details see:
|
|
https://www.rabbitmq.com/runtime.html#busy-waiting.
|
|
|
|
High Availability
|
|
~~~~~~~~~~~~~~~~~
|
|
|
|
RabbitMQ offers two features that, when used together, allow for high
|
|
availability. These are durable queues and classic queue mirroring. Setting the
|
|
flag ``om_enable_rabbitmq_high_availability`` to ``true`` will enable both of
|
|
these features. There are some queue types which are intentionally not mirrored
|
|
using the exclusionary pattern ``^(?!(amq\\.)|(.*_fanout_)|(reply_)).*``.
|