Convert the hello world example to a release

examples/hello_world/Makefile

@@ -0,0 +1,14 @@
+PROJECT = hello_world
+
+DEPS = cowboy
+dep_cowboy = pkg://cowboy master
+
+.PHONY: release clean-release
+
+release: clean-release all
+	relx
+
+clean-release:
+	rm -rf _rel
+
+include ../../erlang.mk

examples/hello_world/README.md

@@ -1,22 +1,25 @@
-Cowboy Hello World
-==================
+Hello world example
+===================
 
-To compile this example you need rebar in your PATH.
+To try this example, you need GNU `make`, `git` and
+[relx](https://github.com/erlware/relx) in your PATH.
 
-Type the following command:
-```
-$ rebar get-deps compile
+To build the example, run the following command:
+
+``` bash
+$ make
 ```
 
-You can then start the Erlang node with the following command:
-```
-./start.sh
+To start the release in the foreground:
+
+``` bash
+$ ./_rel/bin/hello_world_example console
 ```
 
-Then point your browser to the indicated URL.
+Then point your browser at [http://localhost:8080](http://localhost:8080).
 
-Example
--------
+Example output
+--------------
 
 ``` bash
 $ curl -i http://localhost:8080
@@ -25,6 +28,7 @@ connection: keep-alive
 server: Cowboy
 date: Fri, 28 Sep 2012 04:10:25 GMT
 content-length: 12
+content-type: text/plain
 
 Hello world!
 ```

examples/hello_world/rebar.config

@@ -1,4 +0,0 @@
-{deps, [
-	{cowboy, ".*",
-		{git, "git://github.com/extend/cowboy.git", "master"}}
-]}.

examples/hello_world/relx.config

@@ -0,0 +1,2 @@
+{release, {hello_world_example, "1"}, [hello_world]}.
+{extended_start_script, true}.

examples/hello_world/src/hello_world.erl

@@ -1,15 +0,0 @@
-%% Feel free to use, reuse and abuse the code in this file.
-
--module(hello_world).
-
-%% API.
--export([start/0]).
-
-%% API.
-
-start() ->
-	ok = application:start(crypto),
-	ok = application:start(cowlib),
-	ok = application:start(ranch),
-	ok = application:start(cowboy),
-	ok = application:start(hello_world).

examples/hello_world/src/toppage_handler.erl

@@ -7,11 +7,13 @@
 -export([handle/2]).
 -export([terminate/3]).
 
-init(_Transport, Req, []) ->
+init(_Type, Req, []) ->
 	{ok, Req, undefined}.
 
 handle(Req, State) ->
-	{ok, Req2} = cowboy_req:reply(200, [], <<"Hello world!">>, Req),
+	{ok, Req2} = cowboy_req:reply(200, [
+		{<<"content-type">>, <<"text/plain">>}
+	], <<"Hello world!">>, Req),
 	{ok, Req2, State}.
 
 terminate(_Reason, _Req, _State) ->

examples/hello_world/start.sh

@@ -1,3 +0,0 @@
-#!/bin/sh
-erl -pa ebin deps/*/ebin -s hello_world \
-	-eval "io:format(\"Point your browser at http://localhost:8080~n\")."