/usr/share/doc/python-oslo.service-doc/html/usage.html is in python-oslo.service-doc 1.16.0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Usage — oslo.service documentation</title>
<link rel="stylesheet" href="_static/nature.css" type="text/css" />
<link rel="stylesheet" href="_static/pygments.css" type="text/css" />
<link rel="stylesheet" href="_static/tweaks.css" type="text/css" />
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT: './',
VERSION: '',
COLLAPSE_INDEX: false,
FILE_SUFFIX: '.html',
HAS_SOURCE: true
};
</script>
<script type="text/javascript" src="_static/jquery.js"></script>
<script type="text/javascript" src="_static/underscore.js"></script>
<script type="text/javascript" src="_static/doctools.js"></script>
<link rel="index" title="Index" href="genindex.html" />
<link rel="search" title="Search" href="search.html" />
<link rel="top" title="oslo.service documentation" href="index.html" />
<link rel="next" title="Configuration Options" href="opts.html" />
<link rel="prev" title="Installation" href="installation.html" />
</head>
<body role="document">
<div id="header">
<h1 id="logo"><a href="http://www.openstack.org/">OpenStack</a></h1>
<ul id="navigation">
<li><a href="http://www.openstack.org/" title="Go to the Home page" class="link">Home</a></li>
<li><a href="http://www.openstack.org/projects/" title="Go to the OpenStack Projects page">Projects</a></li>
<li><a href="http://www.openstack.org/user-stories/" title="Go to the User Stories page" class="link">User Stories</a></li>
<li><a href="http://www.openstack.org/community/" title="Go to the Community page" class="link">Community</a></li>
<li><a href="http://www.openstack.org/blog/" title="Go to the OpenStack Blog">Blog</a></li>
<li><a href="http://wiki.openstack.org/" title="Go to the OpenStack Wiki">Wiki</a></li>
<li><a href="http://docs.openstack.org/" title="Go to OpenStack Documentation" class="current">Documentation</a></li>
</ul>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body" role="main">
<div class="section" id="usage">
<h1>Usage<a class="headerlink" href="#usage" title="Permalink to this headline">¶</a></h1>
<p>To use oslo.service in a project:</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">oslo_service</span>
</pre></div>
</div>
<div class="section" id="migrating-to-oslo-service">
<h2>Migrating to oslo.service<a class="headerlink" href="#migrating-to-oslo-service" title="Permalink to this headline">¶</a></h2>
<p>The <code class="docutils literal"><span class="pre">oslo.service</span></code> library no longer assumes a global configuration object is
available. Instead the following functions and classes have been
changed to expect the consuming application to pass in an <code class="docutils literal"><span class="pre">oslo.config</span></code>
configuration object:</p>
<ul class="simple">
<li><code class="xref py py-func docutils literal"><span class="pre">initialize_if_enabled()</span></code></li>
<li><a class="reference internal" href="api/periodic_task.html#oslo_service.periodic_task.PeriodicTasks" title="oslo_service.periodic_task.PeriodicTasks"><code class="xref py py-class docutils literal"><span class="pre">oslo_service.periodic_task.PeriodicTasks</span></code></a></li>
<li><a class="reference internal" href="api/service.html#oslo_service.service.launch" title="oslo_service.service.launch"><code class="xref py py-func docutils literal"><span class="pre">launch()</span></code></a></li>
<li><a class="reference internal" href="api/service.html#oslo_service.service.ProcessLauncher" title="oslo_service.service.ProcessLauncher"><code class="xref py py-class docutils literal"><span class="pre">oslo_service.service.ProcessLauncher</span></code></a></li>
<li><a class="reference internal" href="api/service.html#oslo_service.service.ServiceLauncher" title="oslo_service.service.ServiceLauncher"><code class="xref py py-class docutils literal"><span class="pre">oslo_service.service.ServiceLauncher</span></code></a></li>
<li><a class="reference internal" href="api/sslutils.html#oslo_service.sslutils.is_enabled" title="oslo_service.sslutils.is_enabled"><code class="xref py py-func docutils literal"><span class="pre">is_enabled()</span></code></a></li>
<li><a class="reference internal" href="api/sslutils.html#oslo_service.sslutils.wrap" title="oslo_service.sslutils.wrap"><code class="xref py py-func docutils literal"><span class="pre">wrap()</span></code></a></li>
</ul>
<div class="section" id="when-using-service-from-oslo-incubator">
<h3>When using service from oslo-incubator<a class="headerlink" href="#when-using-service-from-oslo-incubator" title="Permalink to this headline">¶</a></h3>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">foo.openstack.common</span> <span class="k">import</span> <span class="n">service</span>
<span class="n">launcher</span> <span class="o">=</span> <span class="n">service</span><span class="o">.</span><span class="n">launch</span><span class="p">(</span><span class="n">service</span><span class="p">,</span> <span class="n">workers</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span>
</pre></div>
</div>
</div>
<div class="section" id="when-using-oslo-service">
<h3>When using oslo.service<a class="headerlink" href="#when-using-oslo-service" title="Permalink to this headline">¶</a></h3>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">oslo_config</span> <span class="k">import</span> <span class="n">cfg</span>
<span class="kn">from</span> <span class="nn">oslo_service</span> <span class="k">import</span> <span class="n">service</span>
<span class="n">CONF</span> <span class="o">=</span> <span class="n">cfg</span><span class="o">.</span><span class="n">CONF</span>
<span class="n">launcher</span> <span class="o">=</span> <span class="n">service</span><span class="o">.</span><span class="n">launch</span><span class="p">(</span><span class="n">CONF</span><span class="p">,</span> <span class="n">service</span><span class="p">,</span> <span class="n">workers</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span>
</pre></div>
</div>
</div>
<div class="section" id="using-oslo-service-with-oslo-config-generator">
<h3>Using oslo.service with oslo-config-generator<a class="headerlink" href="#using-oslo-service-with-oslo-config-generator" title="Permalink to this headline">¶</a></h3>
<p>The <code class="docutils literal"><span class="pre">oslo.service</span></code> provides several entry points to generate a configuration
files.</p>
<ul>
<li><dl class="first docutils">
<dt><a class="reference internal" href="api/service.html#oslo_service.service.list_opts" title="oslo_service.service.list_opts"><code class="xref py py-func docutils literal"><span class="pre">oslo.service.service</span></code></a></dt>
<dd><p class="first last">The options from the service and eventlet_backdoor modules for
the [DEFAULT] section.</p>
</dd>
</dl>
</li>
<li><dl class="first docutils">
<dt><a class="reference internal" href="api/periodic_task.html#oslo_service.periodic_task.list_opts" title="oslo_service.periodic_task.list_opts"><code class="xref py py-func docutils literal"><span class="pre">oslo.service.periodic_task</span></code></a></dt>
<dd><p class="first last">The options from the periodic_task module for the [DEFAULT] section.</p>
</dd>
</dl>
</li>
<li><dl class="first docutils">
<dt><a class="reference internal" href="api/sslutils.html#oslo_service.sslutils.list_opts" title="oslo_service.sslutils.list_opts"><code class="xref py py-func docutils literal"><span class="pre">oslo.service.sslutils</span></code></a></dt>
<dd><p class="first last">The options from the sslutils module for the [ssl] section.</p>
</dd>
</dl>
</li>
<li><dl class="first docutils">
<dt><code class="xref py py-func docutils literal"><span class="pre">oslo.service.wsgi</span></code></dt>
<dd><p class="first last">The options from the wsgi module for the [DEFAULT] section.</p>
</dd>
</dl>
</li>
</ul>
<p><strong>ATTENTION:</strong> The library doesn’t provide an oslo.service entry point.</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ oslo-config-generator --namespace oslo.service.service <span class="se">\</span>
--namespace oslo.service.periodic_task <span class="se">\</span>
--namespace oslo.service.sslutils
</pre></div>
</div>
</div>
</div>
<div class="section" id="launching-and-controlling-services">
<h2>Launching and controlling services<a class="headerlink" href="#launching-and-controlling-services" title="Permalink to this headline">¶</a></h2>
<p>oslo_service.service module provides tools for launching OpenStack
services and controlling their lifecycles.</p>
<p>A service is an instance of any class that
subclasses <a class="reference internal" href="api/service.html#oslo_service.service.ServiceBase" title="oslo_service.service.ServiceBase"><code class="xref py py-class docutils literal"><span class="pre">oslo_service.service.ServiceBase</span></code></a>.
<a class="reference internal" href="api/service.html#oslo_service.service.ServiceBase" title="oslo_service.service.ServiceBase"><code class="xref py py-class docutils literal"><span class="pre">ServiceBase</span></code></a> is an
abstract class that defines an interface every
service should implement. <a class="reference internal" href="api/service.html#oslo_service.service.Service" title="oslo_service.service.Service"><code class="xref py py-class docutils literal"><span class="pre">oslo_service.service.Service</span></code></a> can
serve as a base for constructing new services.</p>
<div class="section" id="launchers">
<h3>Launchers<a class="headerlink" href="#launchers" title="Permalink to this headline">¶</a></h3>
<p>oslo_service.service module provides two launchers for running services:</p>
<blockquote>
<div><ul class="simple">
<li><a class="reference internal" href="api/service.html#oslo_service.service.ServiceLauncher" title="oslo_service.service.ServiceLauncher"><code class="xref py py-class docutils literal"><span class="pre">oslo_service.service.ServiceLauncher</span></code></a> - used for
running one or more service in a parent process.</li>
<li><a class="reference internal" href="api/service.html#oslo_service.service.ProcessLauncher" title="oslo_service.service.ProcessLauncher"><code class="xref py py-class docutils literal"><span class="pre">oslo_service.service.ProcessLauncher</span></code></a> - forks a given
number of workers in which service(s) are then started.</li>
</ul>
</div></blockquote>
<p>It is possible to initialize whatever launcher is needed and then
launch a service using it.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">oslo_config</span> <span class="k">import</span> <span class="n">cfg</span>
<span class="kn">from</span> <span class="nn">oslo_service</span> <span class="k">import</span> <span class="n">service</span>
<span class="n">CONF</span> <span class="o">=</span> <span class="n">cfg</span><span class="o">.</span><span class="n">CONF</span>
<span class="n">service_launcher</span> <span class="o">=</span> <span class="n">service</span><span class="o">.</span><span class="n">ServiceLauncher</span><span class="p">(</span><span class="n">CONF</span><span class="p">)</span>
<span class="n">service_launcher</span><span class="o">.</span><span class="n">launch_service</span><span class="p">(</span><span class="n">service</span><span class="o">.</span><span class="n">Service</span><span class="p">())</span>
<span class="n">process_launcher</span> <span class="o">=</span> <span class="n">service</span><span class="o">.</span><span class="n">ProcessLauncher</span><span class="p">(</span><span class="n">CONF</span><span class="p">,</span> <span class="n">wait_interval</span><span class="o">=</span><span class="mf">1.0</span><span class="p">)</span>
<span class="n">process_launcher</span><span class="o">.</span><span class="n">launch_service</span><span class="p">(</span><span class="n">service</span><span class="o">.</span><span class="n">Service</span><span class="p">(),</span> <span class="n">workers</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span>
</pre></div>
</div>
<p>Or one can simply call <a class="reference internal" href="api/service.html#oslo_service.service.launch" title="oslo_service.service.launch"><code class="xref py py-func docutils literal"><span class="pre">oslo_service.service.launch()</span></code></a> which will
automatically pick an appropriate launcher based on a number of workers that
are passed to it (ServiceLauncher in case workers=1 or None and
ProcessLauncher in other case).</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">oslo_config</span> <span class="k">import</span> <span class="n">cfg</span>
<span class="kn">from</span> <span class="nn">oslo_service</span> <span class="k">import</span> <span class="n">service</span>
<span class="n">CONF</span> <span class="o">=</span> <span class="n">cfg</span><span class="o">.</span><span class="n">CONF</span>
<span class="n">launcher</span> <span class="o">=</span> <span class="n">service</span><span class="o">.</span><span class="n">launch</span><span class="p">(</span><span class="n">CONF</span><span class="p">,</span> <span class="n">service</span><span class="o">.</span><span class="n">Service</span><span class="p">(),</span> <span class="n">workers</span><span class="o">=</span><span class="mi">3</span><span class="p">)</span>
</pre></div>
</div>
<p><em>NOTE:</em> Please be informed that it is highly recommended to use no
more than one instance of ServiceLauncher and ProcessLauncher classes
per process.</p>
</div>
<div class="section" id="signal-handling">
<h3>Signal handling<a class="headerlink" href="#signal-handling" title="Permalink to this headline">¶</a></h3>
<p>oslo_service.service provides handlers for such signals as SIGTERM, SIGINT
and SIGHUP.</p>
<p>SIGTERM is used for graceful termination of services. This can allow a
server to wait for all clients to close connections while rejecting new
incoming requests. Config option graceful_shutdown_timeout specifies how
many seconds after receiving a SIGTERM signal, a server should continue
to run, handling the existing connections. Setting graceful_shutdown_timeout
to zero means that the server will wait indefinitely until all remaining
requests have been fully served.</p>
<p>To force instantaneous termination SIGINT signal must be sent.</p>
<p>On receiving SIGHUP configuration files are reloaded and a service
is being reset and started again. Then all child workers are gracefully
stopped using SIGTERM and workers with new configuration are
spawned. Thus, SIGHUP can be used for changing config options on the go.</p>
<p><em>NOTE:</em> SIGHUP is not supported on Windows.
<em>NOTE:</em> Config option graceful_shutdown_timeout is not supported on Windows.</p>
<p>Below is the example of a service with a reset method that allows reloading
logging options by sending a SIGHUP.</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">oslo_config</span> <span class="k">import</span> <span class="n">cfg</span>
<span class="kn">from</span> <span class="nn">oslo_log</span> <span class="k">import</span> <span class="n">log</span> <span class="k">as</span> <span class="n">logging</span>
<span class="kn">from</span> <span class="nn">oslo_service</span> <span class="k">import</span> <span class="n">service</span>
<span class="n">CONF</span> <span class="o">=</span> <span class="n">cfg</span><span class="o">.</span><span class="n">CONF</span>
<span class="n">LOG</span> <span class="o">=</span> <span class="n">logging</span><span class="o">.</span><span class="n">getLogger</span><span class="p">(</span><span class="n">__name__</span><span class="p">)</span>
<span class="k">class</span> <span class="nc">FooService</span><span class="p">(</span><span class="n">service</span><span class="o">.</span><span class="n">ServiceBase</span><span class="p">):</span>
<span class="k">def</span> <span class="nf">start</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">pass</span>
<span class="k">def</span> <span class="nf">wait</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">pass</span>
<span class="k">def</span> <span class="nf">stop</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">pass</span>
<span class="k">def</span> <span class="nf">reset</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">logging</span><span class="o">.</span><span class="n">setup</span><span class="p">(</span><span class="n">cfg</span><span class="o">.</span><span class="n">CONF</span><span class="p">,</span> <span class="s1">'foo'</span><span class="p">)</span>
</pre></div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="sphinxsidebar">
<div class="sphinxsidebarwrapper">
<h3><a href="index.html">Table Of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">Usage</a><ul>
<li><a class="reference internal" href="#migrating-to-oslo-service">Migrating to oslo.service</a><ul>
<li><a class="reference internal" href="#when-using-service-from-oslo-incubator">When using service from oslo-incubator</a></li>
<li><a class="reference internal" href="#when-using-oslo-service">When using oslo.service</a></li>
<li><a class="reference internal" href="#using-oslo-service-with-oslo-config-generator">Using oslo.service with oslo-config-generator</a></li>
</ul>
</li>
<li><a class="reference internal" href="#launching-and-controlling-services">Launching and controlling services</a><ul>
<li><a class="reference internal" href="#launchers">Launchers</a></li>
<li><a class="reference internal" href="#signal-handling">Signal handling</a></li>
</ul>
</li>
</ul>
</li>
</ul>
<h4>Previous topic</h4>
<p class="topless"><a href="installation.html"
title="previous chapter">Installation</a></p>
<h4>Next topic</h4>
<p class="topless"><a href="opts.html"
title="next chapter">Configuration Options</a></p>
<h3>This Page</h3>
<ul class="this-page-menu">
<li><a href="_sources/usage.txt"
rel="nofollow">Show Source</a></li>
</ul>
<div id="searchbox" style="display: none">
<h3>Quick search</h3>
<form class="search" action="search.html" method="get">
<input type="text" name="q" size="18" />
<input type="submit" value="Go" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
<p class="searchtip" style="font-size: 90%">
Enter search terms or a module, class or function name.
</p>
</div>
<script type="text/javascript">$('#searchbox').show(0);</script>
</div>
</div>
<div class="clearer"></div>
</div>
<div class="related" role="navigation" aria-label="related navigation">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="genindex.html" title="General Index"
accesskey="I">index</a></li>
<li class="right" >
<a href="py-modindex.html" title="Python Module Index"
>modules</a> |</li>
<li class="right" >
<a href="opts.html" title="Configuration Options"
accesskey="N">next</a> |</li>
<li class="right" >
<a href="installation.html" title="Installation"
accesskey="P">previous</a> |</li>
<li class="nav-item nav-item-0"><a href="index.html">oslo.service documentation</a> »</li>
</ul>
</div>
<div class="footer" role="contentinfo">
© Copyright 2016, OpenStack Foundation.
Created using <a href="http://sphinx-doc.org/">Sphinx</a> 1.4.8.
</div>
<script type="text/javascript">
try {
//Tracking docs.openstack.org/developer/<projectname> only
//The URL is built from the project variable in conf.py
var pageTracker = _gat._getTracker("UA-17511903-1");
pageTracker._setCookiePath("/developer/oslo.service");
pageTracker._trackPageview();
} catch(err) {}</script>
</body>
</html>
|