Graham Ollis

NAME

Clustericious::Config - configuration files for Clustericious nodes.

VERSION

version 0.28

SYNOPSIS

In your ~/etc/MyApp.conf file:

 ---
 % extends_config 'global';
 % extends_config 'hypnotoad', url => 'http://localhost:9999', app => 'MyApp';

 url : http://localhost:9999
 start_mode : hypnotoad
 hypnotoad :
    - heartbeat_timeout : 500
 
 arbitrary_key: value

In your ~/etc/globa.conf file:

 ---
 somevar : somevalue

In your ~/etc/hypnotoad.conf:

 listen :
    - <%= $url %>
 # home uses File::HomeDir to find the calling users'
 # home directory
 pid_file : <%= home %>/<%= $app %>/hypnotoad.pid
 env :
    MOJO_HOME : <%= home %>/<%= $app %>

From a Clustericious::App:

 package MyApp;
 
 use Mojo::Base qw( Clustericious::App );
 
 package MyApp::Routes;
 
 use Clustericious::RouteBuilder;
 
 get '/' => sub {
   my $c = shift;
   my $config = $c; # $config isa Clustericious::Config
   
   # returns the value if it is defined, foo otherwise
   my $value = $config->arbitrary_key(default => 'foo');
 };

From a script:

 use Clustericious::Config;
 
 my $c = Clustericious::Config->new("MyApp");
 my $c = Clustericious::Config->new( \$config_string );
 my $c = Clustericious::Config->new( \%config_data_structure );

 print $c->url;
 print $c->{url};

 print $c->hypnotoad->listen;
 print $c->hypnotoad->{listen};
 my %hash = $c->hypnotoad;
 my @ary  = $c->hypnotoad;

 # Supply a default value for a missing configuration parameter :
 $c->url(default => "http://localhost:9999");
 print $c->this_param_is_missing(default => "something_else");

 # Dump out the entire config as yaml
 print $c->dump_as_yaml;

DESCRIPTION

Clustericious::Config reads configuration files which are Mojo::Template's of JSON or YAML files. There should generally be an entry for 'url', which may be used by either a client or a server depending on how this node in the cluster is being used.

After rendering the template and parsing the JSON, the resulting object may be called using method calls or treated as hashes.

Config files are looked for in the following places (in order, where "MyApp" is the name of the app) :

    $CLUSTERICIOUS_CONF_DIR/MyApp.conf
    $HOME/etc/MyApp.conf
    /util/etc/MyApp.conf
    /etc/MyApp.conf

The helper "extends_config" may be used to read default settings from another config file. The first argument to extends_config is the basename of the config file. Additional named arguments may be passed to that config file and used as variables within that file. After reading another file, the hashes are merged (i.e. with Hash::Merge); so values anywhere inside the data structure may be overridden.

YAML config files must begin with "---", otherwise they are interpreted as JSON.

This module provides a number of helpers which can be used to get system details (such as the home directory of the calling user or to prompt for passwords). See Clustericious::Config::Helpers for details.

CONSTRUCTOR

new

Create a new Clustericious::Config object. See the SYNOPSIS for possible invocations.

METHODS

$config->dump_as_yaml

Returns a string with the configuration encoded as YAML.

Clustericious::Config->set_singleton

Cache a config object to be returned by the constructor. Usage:

 Clustericicious::Config->set_singleton(App => $object);

CAVEATS

Some filesystems do not support filenames with a colon (:) character in them, so for apps with a double colon in them (for example Clustericious::HelloWorld), a single dash character will be substituted for the name (for example Clustericious-HelloWorld.conf).

NOTES

This is a beta release. The API may change without notice.

SEE ALSO

Mojo::Template, Hash::Merge, Clustericious, Clustericious::Client, Clustericious::Config::Helpers

AUTHOR

original author: Brian Duggan

current maintainer: Graham Ollis <plicease@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2013 by NASA GSFC.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.




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