Kill-Bill

Web Application Server

Installation

Using rebar:

{deps, [
	{kill_bill, ".*", {hg, "https://bitbucket.org/jjmrocha/kill-bill", "1.0.0"}}
]}.

Start Kill-Bill

Kill-Bill depends on cowboy, jsondoc, erlydtl and gibreel, you need to start cowboy and gibreel before kill-bill.

%% Start cowboy
ok = application:start(crypto),
ok = application:start(ranch),
ok = application:start(cowlib),
ok = application:start(cowboy),
%% Start gibreel
ok = application:start(columbo),
ok = application:start(cclock),
ok = application:start(gibreel),
%% Start Kill-Bill
ok = application:start(kill_bill).

Server Management

API

%% Setup a server
kill_bill:config_server(ServerConfig :: Config) -> {ok, ServerName :: atom()} | {error, Reason :: any()} 
	when Config :: ConfigFile :: string()
                     | {server_config, ServerName :: atom(), Config :: list()}.

%% Start server
kill_bill:start_server(ServerName :: atom()) -> ok | {error, Reason :: any()}.

%% Stop server
kill_bill:stop_server(ServerName :: atom()) -> ok | {error, Reason :: any()}.

%% List all servers
kill_bill:get_server_list() -> list().

Server configuration file

{server_config, ServerName, [
	{host, Host}, 
	{protocol, Protocol}, 
	{ssl, SSLConfig},
	{port, Port},
	{acceptor_number, AcceptorNumber},
	{max_connections, MaxConnections}
]}.

Where:

• ServerName - Server name (it's an atom and is mandatory)
• Host - Host (defaults to '_' - all hosts), examples: "127.0.0.1", "www.gmailbox.org" or "[www.]gmailbox.org"
• Protocol - Http protocol (http or https - defaults to http)
• SSLConfig - Use with protocol = https (defaults to none), it's a proplist with the following properties: cacertfile, certfile and keyfile
• Port - Port number (defaults to 8080)
• AcceptorNumber - Number of processes accepting connections (defaults to 100)
• MaxConnections - Max number of connections (defaults to infinity)

Example: Accept connections on port 8080 for all hosts.

{server_config, my_server, []}.

Web Application Management

API

%% Deploy a WebApp
kill_bill:deploy(ServerName :: atom(), WebAppConfig :: Config) -> ok | {error, Reason :: any()} 
	when Config :: WebAppFile :: string()
                     | {webapp_config, WebAppName :: atom(), Config :: list()}.	

%% Undeploy WebApp
kill_bill:undeploy(WebAppName :: atom()) -> ok | {error, Reason :: any()}.

%% List all WebApps
kill_bill:get_webapp_list() -> WebAppList
	when WebAppList :: [{WebAppName :: atom(), ServerName :: atom()}, ...].

WebApp configuration file

{webapp_config, WebAppName, [
	{context, Context},
	{template, TemplateConfig},
	{resource, ResourceConfig},
	{action, ActionList},
	{static, StaticConfig},
	{session_timeout, SesionTimeout}
]}.

Where:

• WebAppName - WebApp name (it's an atom and is mandatory)
• Context - WebApp context (defaults to "/")
• TemplateConfig - Erlydtl template access configuration (defaults to none), it's a proplist with the following properties: top_page and prefix
  • top_page - Default page (equivalent to index.html, defaults to "index")
  • prefix - URL to template, i.e. /Context/Prefix/TemplateName
• ResourceConfig - Message files (defaults to none), it's a proplist with the following properties: base_name, file_extension and file_dir
  • base_name - Name of the message file (defaults to "message"), the full format is: file_dir/base_name[_language[_country]]file_extension
  • file_extension - Extension of the message files (defaults to ".txt")
  • file_dir - Directory where the message files are located (defaults to "./resource")
• ActionList - List of actions (prefix and callback pairs), each action is define as: {ActionPrefix, ActionCallback}, where:
  • ActionPrefix - URL of action, i.e. /Context/ActionPrefix
  • ActionCallback - Name of the erlang module, must implement the kb_action_handler callback behaviour
• StaticConfig - Static content configuration (defaults to none), it's a proplist with the following properties: path and dir
  • path - URL to file (defaults to "/"), i.e. /Context/Path/FileName
  • dir - Directory with static content (defaults to "./static")
• SesionTimeout - Session timeout in minutes (defaults to 30)

Example

The following code was removed from the example project, that you will find on the "examples" directory.

{ok, ServerID} = kill_bill:config_server("./priv/default-server.config"),
ok = kill_bill:deploy(ServerID, "./priv/root-webapp.config"),
ok = kill_bill:deploy(ServerID, "./priv/examples-webapp.config"),
ok = kill_bill:start_server(ServerID).

kb_action_handler callback

The actions must implement the kb_action_handler callback behaviour.

handle(Method :: binary(), Path :: list(), Request :: #kb_request{}) 
	-> {html, Value :: iodata(), Request1 :: #kb_request{}} 
	 | {json, Value :: any(), Request1 :: #kb_request{}}
	 | {dtl, Template :: module(), Args :: list(), Request1 :: #kb_request{}}
	 | {redirect, Url :: iolist(), Request1 :: #kb_request{}} 
	 | {raw, Status :: integer(), Headers :: list(), Body :: iodata(), Request1 :: #kb_request{}}.

Parameters:

• Method - HTTP Method (GET, POST, ...)
• Path - The URL split by "/", i.e. the request GET /shop/hardware will produce the path = [<<"shop">>, <<"hardware">>]
• Request - Record with the request data

Example

WebApp configuration file:

{webapp_config, examples, [
	{context, "/examples/"},
	{action, [ 
		{"/", examples_action}		
	]}
]}.

Action module:

-module(examples_action).

-behaviour(kb_action_handler).

-export([handle/3]).

handle(_Method, [], Req) ->
	{html, "<html><body>Kill-Bill examples.</body></html>", Req};

handle(_Method, [<<"obj">>, Id, <<"create">>], Req) ->
	Obj = [{id, Id}, {type, <<"obj">>}],
	{json, Obj, Req};

handle(<<"GET">>, [<<"cities">>], Req) ->
	CitiesList = [<<"Lisbon">>, <<"London">>, <<"Madrid">>],
	Args = [{cities, ValueList}],
	{dtl, cities_dtl, Args, Req};

handle(_Method, [<<"google">>], Req) ->
	{redirect, <<"http://www.google.com">>, Req};

handle(_Method, _Path, Req) ->
	{raw, 404, [], "Not found!", Req}.

kb_action_helper Helper module

The module kb_action_helper provides functions to interact with Kill-Bill.

API

%% Retrive WebApp context
kb_action_helper:get_context(Req :: #kb_request{}) -> binary().

%% Retrive args from request
kb_action_helper:get_args(Req :: #kb_request{}) -> {Args, Req1 :: #kb_request{}}
	when Args :: [{Key :: binary(), Value :: binary()}, ...].

%% Retrive JSON from request body
kb_action_helper:get_json(Req :: #kb_request{}) -> {Doc :: jsondoc:jsondoc(), Req1 :: #kb_request{}}.

%% Retrive data from session
kb_action_helper:get_session(Req :: #kb_request{}) -> {SessionData, Req1 :: #kb_request{}}
	when SessionData :: [{Key :: any(), Value :: any()}, ...].

%% Store data in session
kb_action_helper:set_session(SessionData, Req :: #kb_request{}) -> Req1 :: #kb_request{}
	when SessionData :: [{Key :: any(), Value :: any()}, ...].

%% Invalidate session
kb_action_helper:invalidate_session(Req :: #kb_request{}) -> #kb_request{}.

The module kb_action_helper has many more functions.

Kill-Bill tags

Kill-Bill provides two tags to be use on templates:

TAG context

Without parameters, returns the WebApp's context

<form action="{% context %}action" method="post">
...
</form>

With the "file" parameter, the TAG prefixes the path to the file with the WebApp's context:

<img src="{% context file="/images/kill-bill-logo.png" %}">

TAG message

Retrieves the localized message for "key" from the messages file (defined in the WebApp configuration file):

<h1>{% message key="page_title" %}</h1>

Configuration

To use Kill-Bill's tags, add the following to your project's rebar.config:

{erlydtl_opts, [{custom_tags_modules, [kb_dtl_tag]}]}.