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diff --git a/app/static/doc/flask-docs/patterns/fabric.html b/app/static/doc/flask-docs/patterns/fabric.html new file mode 100644 index 0000000..9949480 --- /dev/null +++ b/app/static/doc/flask-docs/patterns/fabric.html @@ -0,0 +1,298 @@ + +<!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>Deploying with Fabric — Flask 0.8 documentation</title> + + <link rel="stylesheet" href="../_static/flasky.css" type="text/css" /> + <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> + + <script type="text/javascript"> + var DOCUMENTATION_OPTIONS = { + URL_ROOT: '../', + VERSION: '0.8', + 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="top" title="Flask 0.8 documentation" href="../index.html" /> + <link rel="up" title="Patterns for Flask" href="index.html" /> + <link rel="next" title="Using SQLite 3 with Flask" href="sqlite3.html" /> + <link rel="prev" title="Deploying with Distribute" href="distribute.html" /> + + + <link rel="apple-touch-icon" href="../_static/touch-icon.png" /> + + <link media="only screen and (max-device-width: 480px)" href="../_static/small_flask.css" type= "text/css" rel="stylesheet" /> + + </head> + <body> + <div class="related"> + <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="sqlite3.html" title="Using SQLite 3 with Flask" + accesskey="N">next</a> |</li> + <li class="right" > + <a href="distribute.html" title="Deploying with Distribute" + accesskey="P">previous</a> |</li> + <li><a href="../index.html">Flask 0.8 documentation</a> »</li> + <li><a href="index.html" accesskey="U">Patterns for Flask</a> »</li> + </ul> + </div> + + <div class="document"> + <div class="documentwrapper"> + <div class="bodywrapper"> + <div class="body"> + + <div class="section" id="deploying-with-fabric"> +<span id="fabric-deployment"></span><h1>Deploying with Fabric<a class="headerlink" href="#deploying-with-fabric" title="Permalink to this headline">¶</a></h1> +<p><a class="reference external" href="http://fabfile.org/">Fabric</a> is a tool for Python similar to Makefiles but with the ability +to execute commands on a remote server. In combination with a properly +set up Python package (<a class="reference internal" href="packages.html#larger-applications"><em>Larger Applications</em></a>) and a good concept for +configurations (<a class="reference internal" href="../config.html#config"><em>Configuration Handling</em></a>) it is very easy to deploy Flask +applications to external servers.</p> +<p>Before we get started, here a quick checklist of things we have to ensure +upfront:</p> +<ul class="simple"> +<li>Fabric 1.0 has to be installed locally. This tutorial assumes the +latest version of Fabric.</li> +<li>The application already has to be a package and requires a working +<cite>setup.py</cite> file (<a class="reference internal" href="distribute.html#distribute-deployment"><em>Deploying with Distribute</em></a>).</li> +<li>In the following example we are using <cite>mod_wsgi</cite> for the remote +servers. You can of course use your own favourite server there, but +for this example we chose Apache + <cite>mod_wsgi</cite> because it’s very easy +to setup and has a simple way to reload applications without root +access.</li> +</ul> +<div class="section" id="creating-the-first-fabfile"> +<h2>Creating the first Fabfile<a class="headerlink" href="#creating-the-first-fabfile" title="Permalink to this headline">¶</a></h2> +<p>A fabfile is what controls what Fabric executes. It is named <cite>fabfile.py</cite> +and executed by the <cite>fab</cite> command. All the functions defined in that file +will show up as <cite>fab</cite> subcommands. They are executed on one or more +hosts. These hosts can be defined either in the fabfile or on the command +line. In this case we will add them to the fabfile.</p> +<p>This is a basic first example that has the ability to upload the current +sourcecode to the server and install it into a pre-existing +virtual environment:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="kn">from</span> <span class="nn">fabric.api</span> <span class="kn">import</span> <span class="o">*</span> + +<span class="c"># the user to use for the remote commands</span> +<span class="n">env</span><span class="o">.</span><span class="n">user</span> <span class="o">=</span> <span class="s">'appuser'</span> +<span class="c"># the servers where the commands are executed</span> +<span class="n">env</span><span class="o">.</span><span class="n">hosts</span> <span class="o">=</span> <span class="p">[</span><span class="s">'server1.example.com'</span><span class="p">,</span> <span class="s">'server2.example.com'</span><span class="p">]</span> + +<span class="k">def</span> <span class="nf">pack</span><span class="p">():</span> + <span class="c"># create a new source distribution as tarball</span> + <span class="n">local</span><span class="p">(</span><span class="s">'python setup.py sdist --formats=gztar'</span><span class="p">,</span> <span class="n">capture</span><span class="o">=</span><span class="bp">False</span><span class="p">)</span> + +<span class="k">def</span> <span class="nf">deploy</span><span class="p">():</span> + <span class="c"># figure out the release name and version</span> + <span class="n">dist</span> <span class="o">=</span> <span class="n">local</span><span class="p">(</span><span class="s">'python setup.py --fullname'</span><span class="p">,</span> <span class="n">capture</span><span class="o">=</span><span class="bp">True</span><span class="p">)</span><span class="o">.</span><span class="n">strip</span><span class="p">()</span> + <span class="c"># upload the source tarball to the temporary folder on the server</span> + <span class="n">put</span><span class="p">(</span><span class="s">'dist/</span><span class="si">%s</span><span class="s">.tar.gz'</span> <span class="o">%</span> <span class="n">dist</span><span class="p">,</span> <span class="s">'/tmp/yourapplication.tar.gz'</span><span class="p">)</span> + <span class="c"># create a place where we can unzip the tarball, then enter</span> + <span class="c"># that directory and unzip it</span> + <span class="n">run</span><span class="p">(</span><span class="s">'mkdir /tmp/yourapplication'</span><span class="p">)</span> + <span class="k">with</span> <span class="n">cd</span><span class="p">(</span><span class="s">'/tmp/yourapplication'</span><span class="p">):</span> + <span class="n">run</span><span class="p">(</span><span class="s">'tar xzf /tmp/yourapplication.tar.gz'</span><span class="p">)</span> + <span class="c"># now setup the package with our virtual environment's</span> + <span class="c"># python interpreter</span> + <span class="n">run</span><span class="p">(</span><span class="s">'/var/www/yourapplication/env/bin/python setup.py install'</span><span class="p">)</span> + <span class="c"># now that all is set up, delete the folder again</span> + <span class="n">run</span><span class="p">(</span><span class="s">'rm -rf /tmp/yourapplication /tmp/yourapplication.tar.gz'</span><span class="p">)</span> + <span class="c"># and finally touch the .wsgi file so that mod_wsgi triggers</span> + <span class="c"># a reload of the application</span> + <span class="n">run</span><span class="p">(</span><span class="s">'touch /var/www/yourapplication.wsgi'</span><span class="p">)</span> +</pre></div> +</div> +<p>The example above is well documented and should be straightforward. Here +a recap of the most common commands fabric provides:</p> +<ul class="simple"> +<li><cite>run</cite> - executes a command on a remote server</li> +<li><cite>local</cite> - executes a command on the local machine</li> +<li><cite>put</cite> - uploads a file to the remote server</li> +<li><cite>cd</cite> - changes the directory on the serverside. This has to be used +in combination with the <cite>with</cite> statement.</li> +</ul> +</div> +<div class="section" id="running-fabfiles"> +<h2>Running Fabfiles<a class="headerlink" href="#running-fabfiles" title="Permalink to this headline">¶</a></h2> +<p>Now how do you execute that fabfile? You use the <cite>fab</cite> command. To +deploy the current version of the code on the remote server you would use +this command:</p> +<div class="highlight-python"><pre>$ fab pack deploy</pre> +</div> +<p>However this requires that our server already has the +<tt class="docutils literal"><span class="pre">/var/www/yourapplication</span></tt> folder created and +<tt class="docutils literal"><span class="pre">/var/www/yourapplication/env</span></tt> to be a virtual environment. Furthermore +are we not creating the configuration or <cite>.wsgi</cite> file on the server. So +how do we bootstrap a new server into our infrastructure?</p> +<p>This now depends on the number of servers we want to set up. If we just +have one application server (which the majority of applications will +have), creating a command in the fabfile for this is overkill. But +obviously you can do that. In that case you would probably call it +<cite>setup</cite> or <cite>bootstrap</cite> and then pass the servername explicitly on the +command line:</p> +<div class="highlight-python"><pre>$ fab -H newserver.example.com bootstrap</pre> +</div> +<p>To setup a new server you would roughly do these steps:</p> +<ol class="arabic"> +<li><p class="first">Create the directory structure in <tt class="docutils literal"><span class="pre">/var/www</span></tt>:</p> +<div class="highlight-python"><pre>$ mkdir /var/www/yourapplication +$ cd /var/www/yourapplication +$ virtualenv --distribute env</pre> +</div> +</li> +<li><p class="first">Upload a new <cite>application.wsgi</cite> file to the server and the +configuration file for the application (eg: <cite>application.cfg</cite>)</p> +</li> +<li><p class="first">Create a new Apache config for <cite>yourapplication</cite> and activate it. +Make sure to activate watching for changes of the <cite>.wsgi</cite> file so +that we can automatically reload the application by touching it. +(See <a class="reference internal" href="../deploying/mod_wsgi.html#mod-wsgi-deployment"><em>mod_wsgi (Apache)</em></a> for more information)</p> +</li> +</ol> +<p>So now the question is, where do the <cite>application.wsgi</cite> and +<cite>application.cfg</cite> files come from?</p> +</div> +<div class="section" id="the-wsgi-file"> +<h2>The WSGI File<a class="headerlink" href="#the-wsgi-file" title="Permalink to this headline">¶</a></h2> +<p>The WSGI file has to import the application and also to set an environment +variable so that the application knows where to look for the config. This +is a short example that does exactly that:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="kn">import</span> <span class="nn">os</span> +<span class="n">os</span><span class="o">.</span><span class="n">environ</span><span class="p">[</span><span class="s">'YOURAPPLICATION_CONFIG'</span><span class="p">]</span> <span class="o">=</span> <span class="s">'/var/www/yourapplication/application.cfg'</span> +<span class="kn">from</span> <span class="nn">yourapplication</span> <span class="kn">import</span> <span class="n">app</span> +</pre></div> +</div> +<p>The application itself then has to initialize itself like this to look for +the config at that environment variable:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">app</span> <span class="o">=</span> <span class="n">Flask</span><span class="p">(</span><span class="n">__name__</span><span class="p">)</span> +<span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="o">.</span><span class="n">from_object</span><span class="p">(</span><span class="s">'yourapplication.default_config'</span><span class="p">)</span> +<span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="o">.</span><span class="n">from_envvar</span><span class="p">(</span><span class="s">'YOURAPPLICATION_CONFIG'</span><span class="p">)</span> +</pre></div> +</div> +<p>This approach is explained in detail in the <a class="reference internal" href="../config.html#config"><em>Configuration Handling</em></a> section of the +documentation.</p> +</div> +<div class="section" id="the-configuration-file"> +<h2>The Configuration File<a class="headerlink" href="#the-configuration-file" title="Permalink to this headline">¶</a></h2> +<p>Now as mentioned above, the application will find the correct +configuration file by looking up the <cite>YOURAPPLICATION_CONFIG</cite> environment +variable. So we have to put the configuration in a place where the +application will able to find it. Configuration files have the unfriendly +quality of being different on all computers, so you do not version them +usually.</p> +<p>A popular approach is to store configuration files for different servers +in a separate version control repository and check them out on all +servers. Then symlink the file that is active for the server into the +location where it’s expected (eg: <tt class="docutils literal"><span class="pre">/var/www/yourapplication</span></tt>).</p> +<p>Either way, in our case here we only expect one or two servers and we can +upload them ahead of time by hand.</p> +</div> +<div class="section" id="first-deployment"> +<h2>First Deployment<a class="headerlink" href="#first-deployment" title="Permalink to this headline">¶</a></h2> +<p>Now we can do our first deployment. We have set up the servers so that +they have their virtual environments and activated apache configs. Now we +can pack up the application and deploy it:</p> +<div class="highlight-python"><pre>$ fab pack deploy</pre> +</div> +<p>Fabric will now connect to all servers and run the commands as written +down in the fabfile. First it will execute pack so that we have our +tarball ready and then it will execute deploy and upload the source code +to all servers and install it there. Thanks to the <cite>setup.py</cite> file we +will automatically pull in the required libraries into our virtual +environment.</p> +</div> +<div class="section" id="next-steps"> +<h2>Next Steps<a class="headerlink" href="#next-steps" title="Permalink to this headline">¶</a></h2> +<p>From that point onwards there is so much that can be done to make +deployment actually fun:</p> +<ul class="simple"> +<li>Create a <cite>bootstrap</cite> command that initializes new servers. It could +initialize a new virtual environment, setup apache appropriately etc.</li> +<li>Put configuration files into a separate version control repository +and symlink the active configs into place.</li> +<li>You could also put your application code into a repository and check +out the latest version on the server and then install. That way you +can also easily go back to older versions.</li> +<li>hook in testing functionality so that you can deploy to an external +server and run the testsuite.</li> +</ul> +<p>Working with Fabric is fun and you will notice that it’s quite magical to +type <tt class="docutils literal"><span class="pre">fab</span> <span class="pre">deploy</span></tt> and see your application being deployed automatically +to one or more remote servers.</p> +</div> +</div> + + + </div> + </div> + </div> + <div class="sphinxsidebar"> + <div class="sphinxsidebarwrapper"><p class="logo"><a href="../index.html"> + <img class="logo" src="../_static/flask.png" alt="Logo"/> +</a></p> + <h3><a href="../index.html">Table Of Contents</a></h3> + <ul> +<li><a class="reference internal" href="#">Deploying with Fabric</a><ul> +<li><a class="reference internal" href="#creating-the-first-fabfile">Creating the first Fabfile</a></li> +<li><a class="reference internal" href="#running-fabfiles">Running Fabfiles</a></li> +<li><a class="reference internal" href="#the-wsgi-file">The WSGI File</a></li> +<li><a class="reference internal" href="#the-configuration-file">The Configuration File</a></li> +<li><a class="reference internal" href="#first-deployment">First Deployment</a></li> +<li><a class="reference internal" href="#next-steps">Next Steps</a></li> +</ul> +</li> +</ul> +<h3>Related Topics</h3> +<ul> + <li><a href="../index.html">Documentation overview</a><ul> + <li><a href="index.html">Patterns for Flask</a><ul> + <li>Previous: <a href="distribute.html" title="previous chapter">Deploying with Distribute</a></li> + <li>Next: <a href="sqlite3.html" title="next chapter">Using SQLite 3 with Flask</a></li> + </ul></li> + </ul></li> +</ul> + <h3>This Page</h3> + <ul class="this-page-menu"> + <li><a href="../_sources/patterns/fabric.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" /> + <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="footer"> + © Copyright 2010, Armin Ronacher. + Created using <a href="http://sphinx.pocoo.org/">Sphinx</a>. + </div> + </body> +</html>
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