log4erl Configuration

https://github.com/ahmednawras/log4erl/blob/master/CONFIGURATION.txt

Configuration Guide:
====================

TOC:
====
* Introduction
* Loggers
- Example
* Appenders
- common properties
- file_appender
- console_appender
- smtp_appender
- syslog_appender

Introduction:
=============
This document explains the format of log4erl configuarion file. The configuration file is simple
and easy to write. At any place in the file, any thing you type after '%' is a comment.
You can find a sample configuration in the file 'log4erl.conf' under 'priv' directory.

* Loggers:
==========
It contains a list of logs with the format below, where
<name> is any name you'd like to call it. <name> can later on be used with any of the log messages
in log4erl API (e.g. log4erl:info/2,3,4). If no value for <name> exists or value of "default" suplied,
then the elements inside '{' and '}' will be applied to the default logger.

logger [<name>] {
...
}

Example:
--------
logger application_logger{
...
}

%% default logger
logger {
...
}

* Appenders:
============
Inside each logger, there can be 1 or more appenders. These appenders can be
added inside loggers according to the format below.

<appender_type> <name> {
...
}

Example:
--------
file_appender file1{
...
}

insider appenders' block, you can add properties for that appender in the format 'property=value'.
Multiple properties are seperated by a comman ','Each appender type has different sets of properties,
which are detailed below.

common properties:
------------------
level = <Level> => level of log (e.g. warn)
format = <F> => format of the output (look at 'Appenders.txt')

file_appender:
--------------
dir = <Dir> => directory of output (e.g. /var/log/my_app)
file = <File> => name of the log file (e.g. my_app_log)
type = <Type> => either size or time. Only size is implemented currently
max = <Max> => Maximum size of each rotation
suffix = <Suf> => Suffix of the log file (e.g. log)
rotation = <R> => number of rotations before over-writing log files

console_appender:
-----------------
Nothing more than common properties.

smtp_appender:
--------------
ip = <IP> => ip of the SMTP server
port = <Port> => SMTP prot [Optional]
no_auth = true|false => if specified, no authentication is performed even if
username or password below is provided
username = <U> => SMTP username
password = <P> => SMTP password
from = <From> => value of the From field [Optional]
to = <To> => email to send to
title = <T> => title of email [Optional]
msg = <Format> => format of the email message [Optional]

syslog_appender:
----------------
facility = <F> => Facility to be used (e.g. ftp)
host = <H> => Host to send syslog messages to [Optional]
port = <P> => syslog port [Optioanl]