zaqar/doc/user-guide/zaqar-config-ref/os-zaqar-configRef.xml
Victoria Martínez de la Cruz 752c6e1cd3 Zaqar configuration reference docs
This change adds the basic configuration reference
in the user guide.

It includes the document structure outline according
the OpenStack configuration reference standard and
a list of configuration options present in zaqar.conf
with a description of default values and value types.

Configuration option tables has been generated using
the autogenerate_config_docs tool in openstack-doc-tools
repo. Needed files to easier update this tables in the
near future are located in the autogen folder.

blueprint document-config-options

Change-Id: I17884400f711f6d2723b0774c20e7df4ffb0e812
2014-09-02 16:04:39 -03:00

257 lines
14 KiB
XML

<?xml version="1.0" encoding="UTF-8"?>
<book xmlns="http://docbook.org/ns/docbook"
xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:xlink="http://www.w3.org/1999/xlink"
version="5.0" xml:id="os-zaqar-configRef">
<title>Messaging and Notifications API v1 Configuration Reference</title>
<titleabbrev>Messaging and Notifications Configuration Reference</titleabbrev>
<info>
<!-- <copyright>
<year>2013</year>
<year>2014</year>
<holder>OpenStack Foundation</holder>
</copyright> -->
<releaseinfo>API v1</releaseinfo>
<productname>Messaging and Notifications</productname>
<pubdate>2014-08-20</pubdate>
<!--Note that the <productname> text matches the first few words of the title. The build system splits the title into productname + rest of title on the pdf cover.-->
<!--If you leave the <pubdate> element empty, the build system inserts today's date automatically. -->
<legalnotice role="apache2">
<annotation>
<remark>Copyright details are filled in by the build
system.
</remark>
</annotation>
</legalnotice>
<abstract>
<para>This document is intended for software developers interested in deploying
the Messaging and Notifications service.
</para>
</abstract>
<revhistory>
<revision>
<date>2014-08-10</date>
<revdescription>
<para>Initial document for OpenStack incubation.</para>
</revdescription>
</revision>
</revhistory>
</info>
<chapter xml:id="introduction">
<title>Introduction to the Messaging and Notifications service</title>
<para>Zaqar is a multi-tenant, fast, reliable, scalable cloud messaging and notification service.
It allows developers to share data between distributed application components performing different tasks,
without losing messages or requiring each component to be always available.</para>
<para>The service features a ReST API, which developers can use to send messages between various
components of their SaaS and mobile applications, by using a variety of communication patterns.</para>
<para>Underlying this API is an efficient messaging engine designed with scalability and security in mind.</para>
<simplesect>
<title>Key features</title>
<para>The Messaging and Notifications service provides the following key features:</para>
<itemizedlist>
<listitem>
<para>Firewall-friendly, HTTP-based API with Keystone support</para>
</listitem>
<listitem>
<para>Multi-tenant queues based on Keystone project IDs</para>
</listitem>
<listitem>
<para>Support for several common patterns including event broadcasting, task distribution, and point-to-point messaging</para>
</listitem>
<listitem>
<para>Component-based architecture with support for custom backends and message filters</para>
</listitem>
<listitem>
<para>Efficient reference implementation with an eye toward low latency and high throughput (dependent on backend)</para>
</listitem>
<listitem>
<para>Highly-available and horizontally scalable</para>
</listitem>
</itemizedlist>
</simplesect>
<simplesect>
<title>Components</title>
<para>The Messaging and Notifications service contains the following components:</para>
<itemizedlist>
<listitem>
<para><emphasis role="bold">Transport backend</emphasis>. The Messaging and Notifications
service requires the selection of a transport specification responsible of the communication
between the endpoints. In addition to the base driver implementation, the Messaging
and Notifications service also provides the means to add support for other transport mechanisms.
The default option is WSGI.
</para>
</listitem>
<listitem>
<para><emphasis role="bold">Storage backend</emphasis>. The Messaging and Notifications service
depends on a storage engine for message persistence. In addition to the base driver implementation,
the Messaging and Notifications service also provides the means to add support for other
storage solutions. The default storage option is MongoDB.
</para>
</listitem>
</itemizedlist>
</simplesect>
</chapter>
<chapter xml:id="configuration">
<title>Configure the Messaging and Notifications service</title>
<section xml:id="configuration-overview">
<title>Overview of zaqar.conf</title>
<para>The <filename>zaqar.conf</filename>
configuration file uses an <link xlink:href="https://en.wikipedia.org/wiki/INI_file">INI file format</link>
as explained in the
<link xlink:href="http://docs.openstack.org/trunk/config-reference/content/config_format.html">"Configuration file format"</link>
section of the <link xlink:href="http://docs.openstack.org/trunk/config-reference">OpenStack Configuration Reference</link>.
</para>
<para>This file is located in <literal>/etc/zaqar</literal> within the Zaqar folder.
When you manually install the Messaging and Notifications service,
you must generate the zaqar.conf file using the config samples
generator located in <literal>tools/config/generate_sample.sh</literal>
and customize it according to your preferences.</para>
<para>Example usage of the sample generator script:
<programlisting>
$ generate_sample.sh -b /opt/stack/zaqar -p zaqar -o /etc/zaqar
</programlisting>
</para>
<simplesect>
<title>Sections</title>
<para>Configuration options are grouped by section. The
Message Queueing configuration file supports the following sections:
<variablelist>
<varlistentry>
<term>
<literal>[DEFAULT]</literal>
</term>
<listitem>
<para>Contains most configuration options. If
the documentation for a configuration
option does not specify its section,
assume that it appears in this
section.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<literal>[drivers]</literal>
</term>
<listitem>
<para>Select drivers.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<literal>[transport]</literal>
</term>
<listitem>
<para>Configures general transport options.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<literal>[drivers:transport:wsgi]</literal>
</term>
<listitem>
<para>Configures the WSGI driver.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<literal>[storage]</literal>
</term>
<listitem>
<para>Configures general storage options.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<literal>[drivers:storage:mongodb]</literal>
</term>
<listitem>
<para>Configures the MongoDB driver.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<literal>[keystone_authtoken]</literal>
</term>
<listitem>
<para>Configures the Keystone Identity Service endpoint.</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</simplesect>
</section>
<section xml:id="config-api">
<title>API options</title>
<para>The Messaging and Notifications service can be configured by changing the following
parameters:
</para>
<xi:include href="common/tables/zaqar-api.xml"/>
</section>
<section xml:id="config-logging">
<title>Configure logging</title>
<para>You can use the zaqar.conf file to configure where the Messaging and Notifications service logs events,
the logging levels and log formats.</para>
<para>To customize logging for the Messaging and Notifications service, use the following configuration
settings in the [DEFAULT] section:</para>
<xi:include href="common/tables/zaqar-logging.xml"/>
</section>
<section xml:id="config-drivers">
<title>Configure drivers</title>
<para>The transport and storage drivers used by the Messaging and Notifications service
are determined by the following options:</para>
<xi:include href="common/tables/zaqar-drivers.xml"/>
</section>
<section xml:id="config-storage">
<title>Configure general storage driver options</title>
<para>The Messaging and Notifications service supports several different backends for storing
messages and their metadata. The recommended storage backend is MongoDB.
The following tables detail the available options:</para>
<xi:include href="common/tables/zaqar-storage.xml"/>
<xi:include href="common/tables/zaqar-mongodb.xml"/>
</section>
<section xml:id="config-transport">
<title>Configure general transport driver options</title>
<para>The Messaging and Notifications service uses WSGI as the default transport mechanism.
The following tables detail the available options:</para>
<xi:include href="common/tables/zaqar-transport.xml"/>
<xi:include href="common/tables/zaqar-wsgi.xml"/>
</section>
<section xml:id="config-auth">
<title>Configure authentication and authorization</title>
<para>All requests to the API may only be performed by an authenticated agent.</para>
<para>The preferred authentication system is the OpenStack Identity service, code-named Keystone.</para>
<para>To authenticate, an agent issues an authentication request to a Keystone Identity Service endpoint.
In response to valid credentials, Keystone responds with an auth token and a service catalog that
contains a list of all services and endpoints available for the given token.</para>
<para>Multiple endpoints may be returned for Zaqar according to physical locations
and performance/availability characteristics of different deployments.</para>
<para>Normally, Keystone middleware provides the <literal>X-Project-Id</literal> header based on the
auth token submitted by the Zaqar client.</para>
<para>For this to work, clients must specify a valid auth token in the <literal>X-Auth-Token</literal>
header for each request to the Zaqar API. The API validates auth tokens against Keystone before
servicing each request</para>
<para>If auth is not enabled, clients must provide the <literal>X-Project-Id</literal> header themselves.</para>
<para>Configure the authentication and authorization strategy through these options:</para>
<xi:include href="common/tables/zaqar-authentication.xml"/>
<xi:include href="common/tables/zaqar-auth_token.xml"/>
</section>
<section xml:id="config-pooling">
<title>Configure pooling</title>
<para>The Messaging and Notifications service supports pooling.</para>
<para>
Pooling aims to make Zaqar highly scalable without losing any of its flexibility
by allowing users to use multiple-backends.
</para>
<para>You can enable and configure pooling with the following options:</para>
<xi:include href="common/tables/zaqar-pooling.xml"/>
</section>
<section xml:id="config-samples">
<title>Messaging and Notifications Service configuration files samples</title>
<para>This example shows the default zaqar.conf file:</para>
<programlisting language="ini">
<xi:include parse="text" href="http://git.openstack.org/cgit/openstack/zaqar/plain/etc/zaqar.conf.sample"/>
</programlisting>
</section>
</chapter>
</book>