Confetti

Confetti is configuration provider for your Erlang applications.

Basically it's application:get_env/2 on steroids.

Features

Management console (accessible via telnet) - maintenance department will love you for this:
- Configuration reload in runtime (designated processes receive notifications on reload)
- Easily extensible with your own management commands (plugins!)
- (TODO) broadcast working configuration across the Erlang cluster
```
 ![Confetti management console](http://mtod.org/assets/c3/w92p4radk4wg8.png)
```
Configuration supervision:
- Increase your system's uptime - previous working configuration is DETS-cached in case someone messes up the configuration files
- Broken config for process_a can not break process_b

Easy to use

application:start(confetti).

then

%% your process
%% (...)
init([]) ->
    confetti:use(my_foo),   %% reads configuration terms
                            %% from "conf/my_foo.conf",
                            %% spawns new configuration provider
                            %% if needed...

    confetti:fetch(my_foo),  %% fetches the configuration terms
    {ok, #state{}}.

%% (...)
%% react to configuration changes
handle_info({config_reloaded, NewConf}, State) -> (...)

Customizable

Write configuration validators and more:

confetti:use(foo, [
    %% Specify config file location
    {location, {"conf/bar", "foo.cnf"},

    %% Make sure it's more than just correct Erlang term
    %% or even transform the terms into something!
    %% Validator funs should accept Config and return {ok, NewConf}
    %% on success, error otherwise.
    {validators, [fun validate_foo_config/1]},

    %% ignore notifications for current process
    {subscribe, false}
]).

Expose any module via the management console:

-module(my_commands).
export([foo/1, foo/3]).

foo(help) ->
    "Foo does bar two times!".
foo(Param1, Param2, Param3) ->
    %% perform command logic
    "bar bar".

Let confetti know about it:

%% conf/mgmt_conf.conf
{port, 50000}.
{plugins, [my_commands]}.

Assuming your application is already running, perform live management configruation reload:

$ telnet localhost 50000

...

(nonode@nohost)> reload mgmt_conf
ok

Provide your own welcome screen to the management console, i.e.:
```
$ figlet MyApp > priv/helo.txt
```

Try it out quickly

Obtain the source code
rebar compile; erl -pa ebin -boot start_sasl -s confetti_app
1> example_srv:start_link().
telnet localhost 50000
Type help for available commands, and help COMMAND for command usage details.

License

BSD License. See LICENSE file for details.

Authors

Adam Rutkowski <adam.rutkowski@jtendo.com>

Contribute!

Feel encouraged to spot bugs/poor code and implement new sexy features.

Also, make sure, you add yourself to the authors where appropriate! Thanks.

paulperegud / confetti