Add a web server example

Explore re-routing in middleware.
author: Adam Cammack <[email protected]> 2013-02-16 02:21:54 -0600
committer: Adam Cammack <[email protected]> 2013-02-16 02:21:54 -0600
commit: f112cdf643c520bb6554a2d8efa882e8e904b984 (patch)
tree: 640ef3b6570c1359345cc8f98854936ca3a67540 /examples/web_server
parent: e3daf439da42283cf65faa3311ff73bb7ffe413b (diff)
download: cowboy-f112cdf643c520bb6554a2d8efa882e8e904b984.tar.gz
cowboy-f112cdf643c520bb6554a2d8efa882e8e904b984.tar.bz2
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13 files changed, 220 insertions, 0 deletions
diff --git a/examples/web_server/README.md b/examples/web_server/README.md
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+Cowboy Static File Handler with Index Support
+=============================================
+
+To compile this example you need rebar in your PATH.
+
+Type the following command:
+```
+$ rebar get-deps compile
+```
+
+You can then start the Erlang node with the following command:
+```
+./start.sh
+```
+
+Cowboy will serve all the files you put in the priv/ directory. You can replace
+the filename given in the example URL with the one of a file you added to this
+directory to receive that file. A middleware has been added that will re-route
+the request to a different handler if the requested path is a directory.
+
+Example
+-------
+
+Point your browser to http://localhost:8080 to see the contents of `priv/`. You
+can click on a link to see that file. If HTML is not preferred, the contents of
+a directory will be listed as a JSON array (e.g. with `curl
+http://localhost:8080`).
diff --git a/examples/web_server/priv/small.mp4 b/examples/web_server/priv/small.mp4
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+++ b/examples/web_server/priv/small.mp4
diff --git a/examples/web_server/priv/small.ogv b/examples/web_server/priv/small.ogv
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+++ b/examples/web_server/priv/small.ogv
diff --git a/examples/web_server/priv/test.txt b/examples/web_server/priv/test.txt
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+If you read this then the static file server works!
diff --git a/examples/web_server/priv/video.html b/examples/web_server/priv/video.html
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+<!DOCTYPE html>
+<html>
+<body>
+	<h1>HTML5 Video Example</h1>
+	<video controls>
+		<source src="small.ogv" type="video/ogg"/> 
+		<source src="small.mp4" type="video/mp4"/>
+	</video>
+	<p>Videos taken from <a href="http://techslides.com/sample-webm-ogg-and-mp4-video-files-for-html5/">TechSlides</a></p>
+</body>
+</html>
diff --git a/examples/web_server/rebar.config b/examples/web_server/rebar.config
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+{deps, [
+	{cowboy, ".*",
+		{git, "git://github.com/extend/cowboy.git", "master"}},
+	{mimetypes, ".*",
+		{git, "git://github.com/spawngrid/mimetypes.git", "master"}},
+	{jsx, ".*",
+		{git, "git://github.com/talentdeficit/jsx.git", "master"}}
+]}.
diff --git a/examples/web_server/src/directory_handler.erl b/examples/web_server/src/directory_handler.erl
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+++ b/examples/web_server/src/directory_handler.erl
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+%% Feel free to use, reuse and abuse the code in this file.
+
+%% @doc Directory handler.
+-module(directory_handler).
+
+%% REST Callbacks
+-export([init/3]).
+-export([rest_init/2]).
+-export([allowed_methods/2]).
+-export([resource_exists/2]).
+-export([content_types_provided/2]).
+
+%% Callback Callbacks
+-export([list_json/2]).
+-export([list_html/2]).
+
+init(_Transport, _Req, _Paths) ->
+	{upgrade, protocol, cowboy_rest}.
+
+rest_init(Req, Paths) ->
+	{ok, Req, Paths}.
+
+allowed_methods(Req, State) ->
+	{[<<"GET">>], Req, State}.
+
+resource_exists(Req, {ReqPath, FilePath}) ->
+	case file:list_dir(FilePath) of
+		{ok, Fs} -> {true, Req, {ReqPath, lists:sort(Fs)}};
+		_Err -> {false, Req, {ReqPath, FilePath}}
+	end.
+
+content_types_provided(Req, State) ->
+	{[
+		{{<<"application">>, <<"json">>, []}, list_json},
+		{{<<"text">>, <<"html">>, []}, list_html}
+	], Req, State}.
+
+list_json(Req, {Path, Fs}) ->
+	Files = [[ <<(list_to_binary(F))/binary>> || F <- Fs ]],
+	{jsx:encode(Files), Req, Path}.
+
+list_html(Req, {Path, Fs}) ->
+	Body = [[ links(Path, F) || F <- [".."|Fs] ]],
+	HTML = [<<"<!DOCTYPE html><html><head><title>Index</title></head>",
+		"<body>">>, Body, <<"</body></html>\n">>],
+	{HTML, Req, Path}.
+
+links(<<>>, File) ->
+	["<a href='/", File, "'>", File, "</a><br>\n"];
+links(Prefix, File) ->
+	["<a href='/", Prefix, $/, File, "'>", File, "</a><br>\n"].
diff --git a/examples/web_server/src/directory_lister.erl b/examples/web_server/src/directory_lister.erl
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+%% Feel free to use, reuse and abuse the code in this file.
+
+-module(directory_lister).
+-behaviour(cowboy_middleware).
+
+-export([execute/2]).
+
+execute(Req, Env) ->
+	case lists:keyfind(handler, 1, Env) of
+		{handler, cowboy_static} -> redirect_directory(Req, Env);
+		_H -> {ok, Req, Env}
+	end.
+
+redirect_directory(Req, Env) ->
+	{Path, Req1} = cowboy_req:path_info(Req),
+	Path1 = << <<S/binary, $/>> || S <- Path >>,
+	{handler_opts, StaticOpts} = lists:keyfind(handler_opts, 1, Env),
+	{dir_handler, DirHandler} = lists:keyfind(dir_handler, 1, StaticOpts),
+	FullPath = resource_path(Path1),
+	case valid_path(Path) and filelib:is_dir(FullPath) of
+		true -> handle_directory(Req1, Env, Path1, FullPath, DirHandler);
+		false -> {ok, Req1, Env}
+	end.
+
+handle_directory(Req, Env, Prefix, Path, DirHandler) ->
+	Env1 = lists:keydelete(handler, 1,
+		lists:keydelete(handler_opts, 1, Env)),
+	{ok, Req, [{handler, DirHandler}, {handler_opts, {Prefix, Path}} | Env1]}.
+
+valid_path([]) -> true;
+valid_path([<<"..">> | _T]) -> false;
+valid_path([<<"/", _/binary>> | _T]) -> false;
+valid_path([_H | Rest]) -> valid_path(Rest).
+
+resource_path(Path) ->
+	{ok, Cwd} = file:get_cwd(),
+	filename:join([Cwd, "priv", Path]).
diff --git a/examples/web_server/src/web_server.app.src b/examples/web_server/src/web_server.app.src
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+%% Feel free to use, reuse and abuse the code in this file.
+
+{application, web_server, [
+	{description, "Cowboy static file handler with directory indexes."},
+	{vsn, "1"},
+	{modules, []},
+	{registered, []},
+	{applications, [
+		kernel,
+		stdlib,
+		cowboy
+	]},
+	{mod, {web_server_app, []}},
+	{env, []}
+]}.
diff --git a/examples/web_server/src/web_server.erl b/examples/web_server/src/web_server.erl
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+%% Feel free to use, reuse and abuse the code in this file.
+
+-module(web_server).
+
+%% API.
+-export([start/0]).
+
+%% API.
+
+start() ->
+	ok = application:start(crypto),
+	ok = application:start(ranch),
+	ok = application:start(cowboy),
+	ok = application:start(web_server).
diff --git a/examples/web_server/src/web_server_app.erl b/examples/web_server/src/web_server_app.erl
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+%% Feel free to use, reuse and abuse the code in this file.
+
+%% @private
+-module(web_server_app).
+-behaviour(application).
+
+%% API.
+-export([start/2]).
+-export([stop/1]).
+
+%% API.
+
+start(_Type, _Args) ->
+	Dispatch = cowboy_router:compile([
+		{'_', [
+			{"/[...]", cowboy_static, [
+				{directory, {priv_dir, web_server, []}},
+				{dir_handler, directory_handler},
+				{mimetypes, {fun mimetypes:path_to_mimes/2, default}}
+			]}
+		]}
+	]),
+	{ok, _} = cowboy:start_http(http, 100, [{port, 8080}], [
+		{env, [{dispatch, Dispatch}]},
+		{middlewares, [cowboy_router, directory_lister, cowboy_handler]}
+	]),
+	web_server_sup:start_link().
+
+stop(_State) ->
+	ok.
diff --git a/examples/web_server/src/web_server_sup.erl b/examples/web_server/src/web_server_sup.erl
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+%% Feel free to use, reuse and abuse the code in this file.
+
+%% @private
+-module(web_server_sup).
+-behaviour(supervisor).
+
+%% API.
+-export([start_link/0]).
+
+%% supervisor.
+-export([init/1]).
+
+%% API.
+
+-spec start_link() -> {ok, pid()}.
+start_link() ->
+	supervisor:start_link({local, ?MODULE}, ?MODULE, []).
+
+%% supervisor.
+
+init([]) ->
+	Procs = [],
+	{ok, {{one_for_one, 10, 10}, Procs}}.
diff --git a/examples/web_server/start.sh b/examples/web_server/start.sh
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+#!/bin/sh
+erl -pa ebin deps/*/ebin -s web_server \
+	-eval "io:format(\"Point your browser at http://localhost:8080/~n\")."
author	Adam Cammack <[email protected]>	2013-02-16 02:21:54 -0600
committer	Adam Cammack <[email protected]>	2013-02-16 02:21:54 -0600
commit	f112cdf643c520bb6554a2d8efa882e8e904b984 (patch)
tree	640ef3b6570c1359345cc8f98854936ca3a67540 /examples/web_server
parent	e3daf439da42283cf65faa3311ff73bb7ffe413b (diff)
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