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diff --git a/docs/en/cowboy/2.4/guide/getting_started/index.html b/docs/en/cowboy/2.4/guide/getting_started/index.html new file mode 100644 index 00000000..e4e30831 --- /dev/null +++ b/docs/en/cowboy/2.4/guide/getting_started/index.html @@ -0,0 +1,321 @@ +<!DOCTYPE html> +<html lang="en"> + +<head> + <meta charset="utf-8"> + <meta name="viewport" content="width=device-width, initial-scale=1.0"> + <meta name="description" content=""> + <meta name="author" content="Loïc Hoguin based on a design from (Soft10) Pol Cámara"> + + <meta name="generator" content="Hugo 0.37.1" /> + + <title>Nine Nines: Getting started</title> + + <link href='https://fonts.googleapis.com/css?family=Open+Sans:400,700,400italic' rel='stylesheet' type='text/css'> + <link href="/css/99s.css?r=1" rel="stylesheet"> + + <link rel="shortcut icon" href="/img/ico/favicon.ico"> + <link rel="apple-touch-icon-precomposed" sizes="114x114" href="/img/ico/apple-touch-icon-114.png"> + <link rel="apple-touch-icon-precomposed" sizes="72x72" href="/img/ico/apple-touch-icon-72.png"> + <link rel="apple-touch-icon-precomposed" href="/img/ico/apple-touch-icon-57.png"> + + +</head> + + +<body class=""> + <header id="page-head"> + <div id="topbar" class="container"> + <div class="row"> + <div class="span2"> + <h1 id="logo"><a href="/" title="99s">99s</a></h1> + </div> + <div class="span10"> + + <div id="side-header"> + <nav> + <ul> + <li><a title="Hear my thoughts" href="/articles">Articles</a></li> + <li><a title="Watch my talks" href="/talks">Talks</a></li> + <li class="active"><a title="Read the docs" href="/docs">Documentation</a></li> + <li><a title="Request my services" href="/services">Consulting & Training</a></li> + </ul> + </nav> + <ul id="social"> + <li> + <a href="https://github.com/ninenines" title="Check my Github repositories"><img src="/img/ico_github.png" data-hover="/img/ico_github_alt.png" alt="Github"></a> + </li> + <li> + <a title="Contact me" href="mailto:[email protected]"><img src="/img/ico_mail.png" data-hover="/img/ico_mail_alt.png"></a> + </li> + </ul> + </div> + </div> + </div> + </div> + + +</header> + +<div id="contents" class="two_col"> +<div class="container"> +<div class="row"> +<div id="docs" class="span9 maincol"> + +<h1 class="lined-header"><span>Getting started</span></h1> + +<div class="paragraph"><p>Erlang is more than a language, it is also an operating system +for your applications. Erlang developers rarely write standalone +modules, they write libraries or applications, and then bundle +those into what is called a release. A release contains the +Erlang VM plus all applications required to run the node, so +it can be pushed to production directly.</p></div> +<div class="paragraph"><p>This chapter walks you through all the steps of setting up +Cowboy, writing your first application and generating your first +release. At the end of this chapter you should know everything +you need to push your first Cowboy application to production.</p></div> +<div class="sect1"> +<h2 id="_prerequisites">Prerequisites</h2> +<div class="sectionbody"> +<div class="paragraph"><p>We are going to use the <a href="https://github.com/ninenines/erlang.mk">Erlang.mk</a> +build system. If you are using Windows, please check the +<a href="http://erlang.mk/guide/installation.html">Installation instructions</a> +to get your environment setup before you continue.</p></div> +</div> +</div> +<div class="sect1"> +<h2 id="_bootstrap">Bootstrap</h2> +<div class="sectionbody"> +<div class="paragraph"><p>First, let’s create the directory for our application.</p></div> +<div class="listingblock"> +<div class="content"><!-- Generator: GNU source-highlight +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><tt>$ mkdir hello_erlang +$ cd hello_erlang</tt></pre></div></div> +<div class="paragraph"><p>Then we need to download Erlang.mk. Either use the following +command or download it manually.</p></div> +<div class="listingblock"> +<div class="content"><!-- Generator: GNU source-highlight +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><tt>$ wget https<span style="color: #990000">:</span>//erlang<span style="color: #990000">.</span>mk/erlang<span style="color: #990000">.</span>mk</tt></pre></div></div> +<div class="paragraph"><p>We can now bootstrap our application. Since we are going to generate +a release, we will also bootstrap it at the same time.</p></div> +<div class="listingblock"> +<div class="content"><!-- Generator: GNU source-highlight +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><tt>$ make -f erlang<span style="color: #990000">.</span>mk bootstrap bootstrap-rel</tt></pre></div></div> +<div class="paragraph"><p>This creates a Makefile, a base application, and the release files +necessary for creating the release. We can already build and start +this release.</p></div> +<div class="listingblock"> +<div class="content"><!-- Generator: GNU source-highlight +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><tt>$ make run +<span style="color: #990000">...</span> +<span style="color: #990000">(</span>hello_erlang@<span style="color: #993399">127.0</span><span style="color: #990000">.</span><span style="color: #993399">0.1</span><span style="color: #990000">)</span><span style="color: #993399">1</span><span style="color: #990000">></span></tt></pre></div></div> +<div class="paragraph"><p>Entering the command <code>i().</code> will show the running processes, including +one called <code>hello_erlang_sup</code>. This is the supervisor for our +application.</p></div> +<div class="paragraph"><p>The release currently does nothing. In the rest of this chapter we +will add Cowboy as a dependency and write a simple "Hello world!" +handler.</p></div> +</div> +</div> +<div class="sect1"> +<h2 id="_cowboy_setup">Cowboy setup</h2> +<div class="sectionbody"> +<div class="paragraph"><p>We will modify the <em>Makefile</em> to tell the build system it needs to +fetch and compile Cowboy:</p></div> +<div class="listingblock"> +<div class="content"><!-- Generator: GNU source-highlight +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><tt><span style="color: #009900">PROJECT =</span> hello_erlang + +<span style="color: #009900">DEPS =</span> cowboy +<span style="color: #009900">dep_cowboy_commit =</span> 2.4.0 + +<span style="color: #009900">DEP_PLUGINS =</span> cowboy + +include erlang.mk</tt></pre></div></div> +<div class="paragraph"><p>We also tell the build system to load the plugins Cowboy provides. +These include predefined templates that we will use soon.</p></div> +<div class="paragraph"><p>If you do <code>make run</code> now, Cowboy will be included in the release +and started automatically. This is not enough however, as Cowboy +doesn’t do anything by default. We still need to tell Cowboy to +listen for connections.</p></div> +</div> +</div> +<div class="sect1"> +<h2 id="_listening_for_connections">Listening for connections</h2> +<div class="sectionbody"> +<div class="paragraph"><p>First we define the routes that Cowboy will use to map requests +to handler modules, and then we start the listener. This is best +done at application startup.</p></div> +<div class="paragraph"><p>Open the <em>src/hello_erlang_app.erl</em> file and add the necessary +code to the <code>start/2</code> function to make it look like this:</p></div> +<div class="listingblock"> +<div class="content"><!-- Generator: GNU source-highlight +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><tt><span style="font-weight: bold"><span style="color: #000000">start</span></span>(<span style="color: #009900">_Type</span>, <span style="color: #009900">_Args</span>) <span style="color: #990000">-></span> + <span style="color: #009900">Dispatch</span> <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_router:compile</span></span>([ + {<span style="color: #FF6600">'_'</span>, [{<span style="color: #FF0000">"/"</span>, <span style="color: #FF6600">hello_handler</span>, []}]} + ]), + {<span style="color: #FF6600">ok</span>, <span style="color: #990000">_</span>} <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000000">cowboy:start_clear</span></span>(<span style="color: #FF6600">my_http_listener</span>, + [{<span style="color: #FF6600">port</span>, <span style="color: #993399">8080</span>}], + #{<span style="color: #0000FF">env</span> <span style="color: #990000">=></span> #{<span style="color: #0000FF">dispatch</span> <span style="color: #990000">=></span> <span style="color: #009900">Dispatch</span>}} + ), + <span style="font-weight: bold"><span style="color: #000000">hello_erlang_sup:start_link</span></span>()<span style="color: #990000">.</span></tt></pre></div></div> +<div class="paragraph"><p>Routes are explained in details in the <a href="../routing">Routing</a> +chapter. For this tutorial we map the path <code>/</code> to the handler +module <code>hello_handler</code>. This module doesn’t exist yet.</p></div> +<div class="paragraph"><p>Build and start the release, then open <a href="http://localhost:8080">http://localhost:8080</a> +in your browser. You will get a 500 error because the module is missing. +Any other URL, like <a href="http://localhost:8080/test">http://localhost:8080/test</a>, will result in a +404 error.</p></div> +</div> +</div> +<div class="sect1"> +<h2 id="_handling_requests">Handling requests</h2> +<div class="sectionbody"> +<div class="paragraph"><p>Cowboy features different kinds of handlers, including REST +and Websocket handlers. For this tutorial we will use a plain +HTTP handler.</p></div> +<div class="paragraph"><p>Generate a handler from a template:</p></div> +<div class="listingblock"> +<div class="content"><!-- Generator: GNU source-highlight +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><tt>$ make new <span style="color: #009900">t</span><span style="color: #990000">=</span>cowboy<span style="color: #990000">.</span>http <span style="color: #009900">n</span><span style="color: #990000">=</span>hello_handler</tt></pre></div></div> +<div class="paragraph"><p>Then, open the <em>src/hello_handler.erl</em> file and modify +the <code>init/2</code> function like this to send a reply.</p></div> +<div class="listingblock"> +<div class="content"><!-- Generator: GNU source-highlight +by Lorenzo Bettini +http://www.lorenzobettini.it +http://www.gnu.org/software/src-highlite --> +<pre><tt><span style="font-weight: bold"><span style="color: #000000">init</span></span>(<span style="color: #009900">Req0</span>, <span style="color: #009900">State</span>) <span style="color: #990000">-></span> + <span style="color: #009900">Req</span> <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_req:reply</span></span>(<span style="color: #993399">200</span>, + #{<span style="color: #990000"><<</span><span style="color: #FF0000">"content-type"</span><span style="color: #990000">>></span> <span style="color: #990000">=></span> <span style="color: #990000"><<</span><span style="color: #FF0000">"text/plain"</span><span style="color: #990000">>></span>}, + <span style="color: #990000"><<</span><span style="color: #FF0000">"Hello Erlang!"</span><span style="color: #990000">>></span>, + <span style="color: #009900">Req0</span>), + {<span style="color: #FF6600">ok</span>, <span style="color: #009900">Req</span>, <span style="color: #009900">State</span>}<span style="color: #990000">.</span></tt></pre></div></div> +<div class="paragraph"><p>What the above code does is send a 200 OK reply, with the +Content-type header set to <code>text/plain</code> and the response +body set to <code>Hello Erlang!</code>.</p></div> +<div class="paragraph"><p>If you run the release and open <a href="http://localhost:8080">http://localhost:8080</a> +in your browser, you should get a nice <code>Hello Erlang!</code> displayed!</p></div> +</div> +</div> + + + + + + + + + + + <nav style="margin:1em 0"> + + <a style="float:left" href="https://ninenines.eu/docs/en/cowboy/2.4/guide/introduction/"> + Introduction + </a> + + + + <a style="float:right" href="https://ninenines.eu/docs/en/cowboy/2.4/guide/flow_diagram/"> + Flow diagram + </a> + + </nav> + + + + +</div> + +<div class="span3 sidecol"> + + +<h3> + Cowboy + 2.4 + + User Guide +</h3> + +<ul> + + <li><a href="/docs/en/cowboy/2.4/guide">User Guide</a></li> + + + <li><a href="/docs/en/cowboy/2.4/manual">Function Reference</a></li> + + +</ul> + +<h4 id="docs-nav">Navigation</h4> + +<h4>Version select</h4> +<ul> + + + + <li><a href="/docs/en/cowboy/2.4/guide">2.4</a></li> + + <li><a href="/docs/en/cowboy/2.3/guide">2.3</a></li> + + <li><a href="/docs/en/cowboy/2.2/guide">2.2</a></li> + + <li><a href="/docs/en/cowboy/2.1/guide">2.1</a></li> + + <li><a href="/docs/en/cowboy/2.0/guide">2.0</a></li> + + <li><a href="/docs/en/cowboy/1.0/guide">1.0</a></li> + +</ul> + +</div> +</div> +</div> +</div> + + <footer> + <div class="container"> + <div class="row"> + <div class="span6"> + <p id="scroll-top"><a href="#">↑ Scroll to top</a></p> + <nav> + <ul> + <li><a href="mailto:[email protected]" title="Contact us">Contact us</a></li><li><a href="https://github.com/ninenines/ninenines.github.io" title="Github repository">Contribute to this site</a></li> + </ul> + </nav> + </div> + <div class="span6 credits"> + <p><img src="/img/footer_logo.png"></p> + <p>Copyright © Loïc Hoguin 2012-2018</p> + </div> + </div> + </div> + </footer> + + + <script src="/js/custom.js"></script> + </body> +</html> + + |